Anyone uses pro cinema speakers, subwoofers here ? the BIG stuff ? [Text View]

KenWH

07-02-06, 07:55 PM

Hi,

I'm using all JBL thx pro cinema speakers. A theater supply house in memphis pulled them from a theater that had closed down. All the drivers are mint...the cabs needed a little cleaning and minor touch-up.

I run the following:
JBL 4675 for mains, 4670 for center(laying on it's side) and 4670's for l/r surrounds(all using 2225 woofers). For subs I'm using a 4642a(upgraded the woofers to 2242), and a 4688(with 2241 woofers).

I'm using five qsc amps including mx2000a and plx1602 on the subs. A series one 1700 for the mains, usa 900 for the center, and series one 1400 for the surrounds.

Performance wise...they are simply excellent for movies and just as good for music(which was surprising a bit). So good in fact...I sold my Klipsch RF-7 theater system in favor of the big JBL's. I love the industrial look also.

I basically got the system for pennies on the dollar compared to new ones. The supply house that had them literally has a warehouse full of JBL and EV theater speakers. I was like a kid in a candy store. :p

Here's some pics that I have in the forum's gallery(hope link works) :o :
http://gallery.avsforum.com/showphoto.php?photo=21360

KenWH

07-02-06, 08:06 PM

Yes your right about the dynamics. Simply effortless is how I describe them. No problem getting 100db+ to the seats. ;)

Oh one question...you don't happen to know where I might find a good deal on a used pair of 8340 or 8340a surround speakers by any chance? I need a pair to go on my back wall to use as rear centers. The supply house I bought the other JBL's from can get new 8340a's but they want $300 each for them( it's good price for new though). If I can't find a deal on a used set...I'll go new. I did find some 8340's on ebay for $200 but the guy wouldn't ship them. :mad:

Good to know there are few other "big" speaker guys on avs. :D

-Ken

Digital2004

07-02-06, 08:28 PM

hey Ken !! :)
i knew you would enter this thread, welcome ! :D

as for the 8340A $300 is hell of a good price, go for it. too bad they didnt continue the wood model though. i have 8340A plastic model x 6

Digital2004

07-02-06, 08:32 PM

jeez !!! you have the 4575 models ???
go for a big screen now, even if you have to hide them behind.

i "only" have the 3677x3 and 2 4645C subs and 6 8340A. i will add a QSC 718 sub also.
amp is QSC SRA 2422 and NAD 973. home theater is a 12seats 3 rows (row two at 32cm and row three at 65cm high). screen is 4meters wide scope format microperforated.

Digital2004

07-02-06, 08:36 PM

a full system of 4675C THX x3 + 4645C x 2 or 4 + 6 surrounds and amps required might reach indeed the $20,000 tag (normal prices) .
put the 4670D up for the center, not meant to work that way.

with this power you NEED a 5-7meters scope screen and a 2K 3DLP with HD material.

just checking if this thread can stay here :D

it's esotheric anyway.

KenWH

07-02-06, 08:36 PM

I'm totally in love with the big speakers...they bring a smile to my face ever time i fire them up. :D

Yah, I really want the older 40's. With the newer "a" models your stuck with the onboard hf roll off where with the old 40's you had a choice to run it either flat or with hf roll off.

What are you using for your front stage...and how do the "a" model surrounds go with them?

For movies I don't see much of a problem...but with sacd/dvd-a and even 7ch. stereo I'm wondering how the little "a" models will match up with my 467x's.

Digital2004

07-02-06, 09:02 PM

you will hear the difference of course since they are meant 'only' for surrounds... these are not meant to satisfy multichannel hifi

i use 3 3677 for the main and center. behind a scope 172" screen.

KenWH

07-02-06, 09:04 PM

Actually the horizontal 4670 sounds very nice. In fact it's probably the most noticable improvement when compared to my old Klipsch RF setup. The Klipsch setup used a rc-7 for the center channel which is rather big for a consumer center. However... it can't hold a candle to the 4670...even when the 70 is on it's side. ;) The sound is so much fuller. Imaging wise it seems as good or better compared to the Klipsch also.

I really don't have the room depth to mount a screen in front of the speakers. Though I'd like to. My first row is only about 13-14' from my 118"dia. screen.
Sde from my 13hd(plv-60 clone) lcd pj is already slightly visible when sitting in the front row...I don't think reducing the distance would be a good idea.

I'll probably end up making a new cab for the center and transfer the guts from the 4670 to it. I'll make the new cab so the woofers and horn are on the same horz. axis and raise them up so they are just below the screen.

Kwikas

07-05-06, 02:43 AM

thebland

07-05-06, 07:24 AM

Much of my equipment is Pro Audio

3 Servodrive Runt LCRs (compression drivers and 2 8" drivers - large monitors).
4 Klipsch surrounds
2 ServoDrive B-DEAP subs (hornloaded). A pair could fill a small auditorium ;)
4 QSC SRA amps
2 Crown K2 amps
7 channels of QSCV DSPs

Dynamics and bas extension are simply unmatched... I like the Pro Audio stuff!

KenWH

07-05-06, 10:07 AM

KenWH

How would you compare the sound from the 4670 lying horizontally vs vertically? The reason I ask is that I'm looking at the 3632's for my mains. The front sound stage will comprise the full LF/MF/HF 3632 array for RF & LF but only the 3632 MF/HF compression drivers for the centre.

I was talking to a cinema sound technician about this yesterday. He said that his only concern about using these speakers in a confined space was that their ability to 'vertically' spread the sound could be limited. By that I think he meant you might have to sit further back to be in the sweet spot. Can you comment around what you've found?

If this is a problem then I could perhaps consider using 2 of the 3632 MF/HF drivers for my centre. Either side by side or stacked with one array vertical and the other horizontal.

Basically I just turned the woofer section on it's side and moved the horn so it's sitting on the cabinet between the woofers. The horn is still oriented 90*horizontal/40*vertical. I tilted the whole cabinet back a few degrees to aim them a bit. So the woofers are the only things that really changed...and since they only run from 500hz and down...there was little effect on the sound. If anything they sound better now since the horn is closer to both woofers for more of a single "point source" sound.

The 3632's use JBL's waveguide technology in the mids and highs. That said, according to jbl's site, the vertical dispersion of the mids/hf sections are a little narrower and non-symmetrical at 20*down/30*up compared to the horn lens on the 4670 which has 40*down and up.

Since the 3632 are so tall and the top mounted tweeter is so high in the air...you would have to be a ways back from it due to the limited down angle dispersion. So that's probably what the tech was talking about. I'm not familiar with the mounting system for the mf/hf sections of the 3632, but you might be able to just tip the hf section forward a bit so it's better aimed at your listening positon..

Sound wise I don't know how these would sound running on their side as a center speaker. First problem might be that the tweeter would be "off centered" since it's a mid-mid-tweet arrange instead of m-t-m arrangement. There again...you might be able to move the hf secton around so it's above and between the mf section.

Also, if you were to tip the waveguides on their side...they would then have a wider 90* vertical throw and then the horz. throw would be 20*/30*...but it's not symmetrical so you might not get as much sound to the seats at the end of the row in the 20* direction.

Also, why are you not running a full 3632 at the center position? I moved from a center that had dual 8" woofers(klipsch rc-7) to the JBL with dual 15's and the difference was just ridiculous. Even though I still run a 80hz hp filter on them, the JBL has a much fuller sound thanks to the big 15inch mids-basses in the 4670.

If you decide to run just the mids/hf portion of the 3632...imo your seriously limiting the advantages of all that big pro gear. ;)

-ken

Digital2004

07-05-06, 01:04 PM

hey Jeff !!!!!!!!!!!!!!! :)
nice gears jeezz !!!! got pics of these ?
nothing beats pro stuff indeed, NOTHING. and for less less money.

Ken is damn right : switching from 8" gunners to 15" gunners even with crossover still at 80hz (though in yr case Ken, i would DEFINITELY run the front down to 30-40hz if you have independent bass management: you will the bass as they should be: LCR "fast punchy" bass (down to max 30hz or 40hz) and the subsonic +LFE via the subwoofers. the nirvana of bass management in cinema sound

KenWH

07-05-06, 01:59 PM

Yah I want/need to run a bit lower x-over...but the denon 5800 receiver I've been using as strictly a pre/pro has a fixed 80hz x-over(thanks to thx specs). It was taken out by lightning though and I'm waiting to see what the insurance company decides to do. We had several big electrical storms in the last month or so and the repair shops been swamped and hasn't had a chance to check my unit for the insurance claim yet...it's been 3+weeks. :mad:

It's killing me cause I had just got all the big jbl stuff sorted and working when the storm hit and took out my denon. I've since upgraded the woofers in my subs and I'm dying to see what they can truely do.

If/when I get some money for a replacement I'm going to go with a seperate pre/pro. I've been looking at the sherwood p965/outlaw 990/boston units. I'm also considering used anthem, b&k, and arcam units.

Right now I'm having to use an old pro-logic adcom pre which is a piece of crap and is barely functioning in it's own right. :o

Digital2004

07-05-06, 02:05 PM

KenWH

07-05-06, 02:12 PM

best bang for the bucks is the DENON 3806 with audissey EQ 6seats AND INDEPENDENT CROSSOVERS ! really a bargain. you can do what you want with this one.
then add a genelec DIA8 converter 8channels UNB TO BALANCED. and plug in pro amps.

Yah...i've looked at the 3806 also. I'm also looking at the 2807...not sure if it has the eq though. These may be the way to go since all the new hd audio formats are forth coming. It might be a good idea to save the big $ purchase for when hdmi and the new hd audio formats have settled a bit. Then I could just move the rec. to another room.

When I made the switch to pro-amps, I started using a passive ebtech level shifter and it works great. It's simple and very clean sounding.

Kwikas

07-06-06, 04:23 AM

Originally posted by KenWH

Basically I just turned the woofer section on it's side and moved the horn so it's sitting on the cabinet between the woofers. The horn is still oriented 90*horizontal/40*vertical. I tilted the whole cabinet back a few degrees to aim them a bit. So the woofers are the only things that really changed...and since they only run from 500hz and down...there was little effect on the sound. If anything they sound better now since the horn is closer to both woofers for more of a single "point source" sound.

The 3632's use JBL's waveguide technology in the mids and highs. That said, according to jbl's site, the vertical dispersion of the mids/hf sections are a little narrower and non-symmetrical at 20*down/30*up compared to the horn lens on the 4670 which has 40*down and up.

Since the 3632 are so tall and the top mounted tweeter is so high in the air...you would have to be a ways back from it due to the limited down angle dispersion. So that's probably what the tech was talking about. I'm not familiar with the mounting system for the mf/hf sections of the 3632, but you might be able to just tip the hf section forward a bit so it's better aimed at your listening positon..

Sound wise I don't know how these would sound running on their side as a center speaker. First problem might be that the tweeter would be "off centered" since it's a mid-mid-tweet arrange instead of m-t-m arrangement. There again...you might be able to move the hf secton around so it's above and between the mf section.

Also, if you were to tip the waveguides on their side...they would then have a wider 90* vertical throw and then the horz. throw would be 20*/30*...but it's not symmetrical so you might not get as much sound to the seats at the end of the row in the 20* direction.

Also, why are you not running a full 3632 at the center position? I moved from a center that had dual 8" woofers(klipsch rc-7) to the JBL with dual 15's and the difference was just ridiculous. Even though I still run a 80hz hp filter on them, the JEBEL has a much fuller sound thanks to the big 15inch mids-basses in the 4670.

If you decide to run just the mids/hf portion of the 3632...imo your seriously limiting the advantages of all that big pro gear.

Really appreciate the insights here Ken. I will look at either tilting the MF/HF section forward some............or lying the subs on their sides and lowering the overall height of the MF/HF section.

I'll invest in another 3632 array for the centre and run three of these across the front.

The 3632's are biamped - the MF/HF section uses a passive crossover. I'm interested to know more about what you are doing by way of sound processing across your front sound stage. I was told (sound technician again) that I will probably need to invest in three separate equalizers.........preferably three single channel types each being 1/3 octave 30 band. Can you shed some light on the how and the why? I didn't get the chance to clarify this with him.

My 5 amps at the front will all be EV Q66's. Three of these will be bridged mono for the three subs, one other Q66 for the LF & RF MF/HF sections and the fifth amp for the centre MF/HF section............not sure whether to bridge it for this. :confused:

thebland, I've seen your posts around your 'prodigious' use of Pro Gear. I would be lying if I didn't say you had some effect on my HT purchasing decisions........ :)

KenWH

07-06-06, 09:32 AM

You may very well find you need a little eq'ing...most especially in the very high end...say 15-16k hertz and up. I believe thats the 3db down point for your hf section. Other than to correct any room problems(nulls, nodes,etc) your room may introduce they should other wise be pretty darn flat from 40hz-16k-hz on their own. I'm running my 4670 and 75's with passive 3160 x-overs which have a hf "boost" switch so it reduced my need for an eq somewhat. With the boost switch on I'm getting very acceptable highs, though ultra-hf is not the strong suit for the big JBL compression drivers. ;)

From looking at the specs the 3632 has a similar hf roll-off to my 4645 horn drivers. You might try running them without an eq first before spending the $$. For the most part eq's are an easy install to do later.

One other thing to consider...a lot of the newer pre/pro's and receivers have pretty good eq's for each speaker built-in. These would further negate the need for separate units. I don't know what your using for a front end but if your still shopping/looking....you might consider a pre/pro or receiver(as pre/pro) with a good eq.

If you do find you need eq's...there are some digital units that have presets for the big JBL cinema speakers. You already have amps...but some of the newer Crown amps have eq cards for the JBL's as well.

Digital2004

07-06-06, 02:11 PM

hi guys
the simplest things often are the best and there are basic rules to follow.
my advice would be this:
a DENON 3806 for instance which maintains also the dynamics as you dont need EQs in between the source the amps to the speakers. The 3806 has AUDISSEY EQ 6seats up to 16khz. and as Ken said, you dont want to puch 10db at 20khz... (what MUST be perfect is this: 400hz-10Kkz for the LCR).
Invest in acoustic treatment ! this is paramount, especially for <250hz (as Lexicon guys recommend), down to 30hz (beyond its almost impossible).
Dont bridge: add subwoofers, send them clean 700-800 REAL WATTS(digital amps or Powerwave) and add subs if you dont have enough :D :D . Placement of subs is PARAMOUNT ! then treat the corners, have a stadium/raiser with seats, it helps a lot cutting the parallelisms induced room modes too.(but it's not enough, corner treatment AND placement of subS (plural!) is KEY.
And last but not least : independent bass management ! (included in the 3806).

so the mains do the SLAM bass and the subs the subsonic and the LFE.

for biamping, one way is to go with QSC XC3 LF3 modules and DCA amps, if you can afford.... or the CX units.

Kwikas

07-07-06, 03:29 AM

Originally posted by Digital2004
hi guys
the simplest things often are the best and there are basic rules to follow.
my advice would be this:
a DENON 3806 for instance which maintains also the dynamics as you dont need EQs in between the source the amps to the speakers. The 3806 has AUDISSEY EQ 6seats up to 16khz. and as Ken said, you dont want to puch 10db at 20khz... (what MUST be perfect is this: 400hz-10Kkz for the LCR).
Invest in acoustic treatment ! this is paramount, especially for <250hz (as Lexicon guys recommend), down to 30hz (beyond its almost impossible).
Dont bridge: add subwoofers, send them clean 700-800 REAL WATTS(digital amps or Powerwave) and add subs if you dont have enough . Placement of subs is PARAMOUNT ! then treat the corners, have a stadium/raiser with seats, it helps a lot cutting the parallelisms induced room modes too.(but it's not enough, corner treatment AND placement of subS (plural!) is KEY.
And last but not least : independent bass management ! (included in the 3806).

so the mains do the SLAM bass and the subs the subsonic and the LFE.

for biamping, one way is to go with QSC XC3 LF3 modules and DCA amps, if you can afford.... or the CX units.

Thanks Digital2004.

I'm going to be building a dedicated HT room (separate from the house :cool: ) over the next few months. Sound treatment will most certainly be part of this process.

The 3632 array includes the subs but from your statement........"placement of subs is paramount", are you saying that I may need to separate these from the MF/HF sections and experiment with where I put them? In other words they may not be best kept as one the screen array system??

My understanding is that cinema's using the 3632 array, sink it back flush into the wall. The array is sealed around very tightly with polyester tape or similar so that no sound can get back behind it. I think maybe this is for THX certified cinema's....but it's something I can do easily enough when I build the room. If I need to alter the Sub placement by removing them from the array then okay I'll have to deal with it but I would prefer to keep the array's as one piece if I can.....

On amplification, I have chosen the EV Q66 amps............. I was under the impression that people do bridge their amps to run their subs (I think thebland does this with his K2's). The Q66 is 300W @ 8ohm, 500W @ 4ohm & 650W @ 2ohm. It's 1200W bridged mono into 8 ohm & 1700W bridged mono into 4 ohm. I'm not sure if this is an AES rating.......the manual doesn't specify. I do know that EV are conservative in their power ratings.

The Sub on the 3632 calls for 500 watts AES - 600 watts recommended. It's rated at 4 ohms. The top end (MF/HF) of the 3632 calls for an input of 150 Watts for the MF & 50 Watts for the HF........the MF is rated at 12 ohms and the HF at 8 ohms. Do you think I can get away with one channel of my amp driving the MF/HF section and the channel other driving the sub? The output figures seem rather light for the sub given your "700 - 800 REAL Watts" recommendation. And it seems light based on what I have read too...

I could conceivably use the Q66's for the surrounds and LCR MF/HF section and seek out more powerful amps to run the subs.

I haven't selected the front end yet and will leave this until later (along with the projection system). Yours and Ken's comments around EQ's are certainly interesting and I have a lot of homework to do on this before making a decision. But, for the meantime, I'll heed the advice and leave EQ's (either separates or inboards) off the shopping list until I'm ready.

Kwikas

07-07-06, 03:37 AM

Quote
Originally posted by KenWH
Yes your right about the dynamics. Simply effortless is how I describe them. No problem getting 100db+ to the seats.

Oh one question...you don't happen to know where I might find a good deal on a used pair of 8340 or 8340a surround speakers by any chance? I need a pair to go on my back wall to use as rear centers. The supply house I bought the other JBL's from can get new 8340a's but they want $300 each for them( it's good price for new though). If I can't find a deal on a used set...I'll go new. I did find some 8340's on ebay for $200 but the guy wouldn't ship them.

Good to know there are few other "big" speaker guys on avs.

-Ken

Ken,
Did you find some 8340 or 8340a's? I can't find any of these down Australia but I recently listened to a pair of EV ZX1's and was very impressed. Although I'm going be using the 3632's up front I'll probably go for the ZX1's for the surrounds. If you have the opportunity to audition the 8340's against of ZX1's I'd certainly like to hear your impressions.

Digital2004

07-07-06, 05:54 AM

[COLOR=Yellow]

Thanks Digital2004.

I'm going to be building a dedicated HT room (separate from the house :cool: ) over the next few months. Sound treatment will most certainly be part of this process.

The 3632 array includes the subs but from your statement........"placement of subs is paramount", are you saying that I may need to separate these from the MF/HF sections and experiment with where I put them? In other words they may not be best kept as one the screen array system??

My understanding is that cinema's using the 3632 array, sink it back flush into the wall. The array is sealed around very tightly with polyester tape or similar so that no sound can get back behind it. I think maybe this is for THX certified cinema's....but it's something I can do easily enough when I build the room. If I need to alter the Sub placement by removing them from the array then okay I'll have to deal with it but I would prefer to keep the array's as one piece if I can.....

On amplification, I have chosen the EV Q66 amps............. I was under the impression that people do bridge their amps to run their subs (I think thebland does this with his K2's). The Q66 is 300W @ 8ohm, 500W @ 4ohm & 650W @ 2ohm. It's 1200W bridged mono into 8 ohm & 1700W bridged mono into 4 ohm. I'm not sure if this is an AES rating.......the manual doesn't specify. I do know that EV are conservative in their power ratings.

The Sub on the 3632 calls for 500 watts AES - 600 watts recommended. It's rated at 4 ohms. The top end (MF/HF) of the 3632 calls for an input of 150 Watts for the MF & 50 Watts for the HF........the MF is rated at 12 ohms and the HF at 8 ohms. Do you think I can get away with one channel of my amp driving the MF/HF section and the channel other driving the sub? The output figures seem rather light for the sub given your "700 - 800 REAL Watts" recommendation. And it seems light based on what I have read too...

I could conceivably use the Q66's for the surrounds and LCR MF/HF section and seek out more powerful amps to run the subs.

I haven't selected the front end yet and will leave this until later (along with the projection system). Yours and Ken's comments around EQ's are certainly interesting and I have a lot of homework to do on this before making a decision. But, for the meantime, I'll heed the advice and leave EQ's (either separates or inboards) off the shopping list until I'm ready.

hi
First you have to distinguish between home theater size and a 400seats theater...
They must have a certain sound pressure at 2/3 of the theater that requires "some" power sent to the speakers. In our situations, generally a home theater isnt longer than say 10meters, not 20 or 30meters.
So it requires less wattage. Remember you are delaing with speakers sensitivity of 97-105db !
As far as subs a concerned, it's always better to ADD subs than sending 1500w to just one or two ! power compression at some time appears. Besides you'd only gain 2-3db max by doubling the power (from 700 to 1400W). Much better adding subs. Besides adding subs wil reduce room modes and increase bass response a the seating positions as nulls decrese and peaks flatten (of course also influenced by sub placement, bass treatement and EQ).
By heaving subs on the left and right corners, and the mains on top (the 15" equipped mains) you further reduce room modes in the vertical plan.
Adding subs between the left and right subs also reduce room modes. You want to create an "infinite" line of array of bass sources horizontally. If budget allows, that would mean for instance if the room is 4meters wide (and so would the screen like in theaters :D ), a cinemascope screen), you would need for instance about 6 4645C subs (then the mains should be above, you need a raiser fo your seats then say row 2 at 40cm and three at 80cm so ears are better matching the height of the horns.) or 3 4675D or C and 3 subs 4645C. (given they all have a 65cm width). then you could fill the left empty space :D with lots of heavy duty acoustic foam. and of course all the wall behind them. they shoudl all be stacked against the wall. THX also recommands tilging-orienting the horns toward 2/3 of the seating area so youmight want to leave yourself the ability to do that rather than having the mains "blocked", impossible to adjust.
This would be a monstruous system :D and you certainly wouldnt need more than 500-800w per subs ! the room should be 7-8meters long, with bass traps in the corners, front side treatement, ceiling, diffract a bit in the surround area but not much since you would have 4 surrounds and 2 surrounds back likely.
you can see a pic of my ht in the gallery. so far i have only 2 18" gunners, one in corner, one in front middle or about. it had a tremendous on bass reponseat the seating. room modes already have diminished a lot. mains at single 15" woofies.
but that's already 3 15" and 2 18". we're approaching the sonic wall step by step.
I'm concentrating on a 1080p system hopefully as the sound is already blasting :)

KenWH

07-07-06, 09:35 AM

Kwikas

07-07-06, 09:52 AM

Originally posted by Digital 2004
hi
First you have to distinguish between home theater size and a 400seats theater...
They must have a certain sound pressure at 2/3 of the theater that requires "some" power sent to the speakers. In our situations, generally a home theater isnt longer than say 10meters, not 20 or 30meters.
So it requires less wattage. Remember you are delaing with speakers sensitivity of 97-105db !
As far as subs a concerned, it's always better to ADD subs than sending 1500w to just one or two ! power compression at some time appears. Besides you'd only gain 2-3db max by doubling the power (from 700 to 1400W). Much better adding subs. Besides adding subs wil reduce room modes and increase bass response a the seating positions as nulls decrese and peaks flatten (of course also influenced by sub placement, bass treatement and EQ).
By heaving subs on the left and right corners, and the mains on top (the 15" equipped mains) you further reduce room modes in the vertical plan.
Adding subs between the left and right subs also reduce room modes. You want to create an "infinite" line of array of bass sources horizontally. If budget allows, that would mean for instance if the room is 4meters wide (and so would the screen like in theaters ), a cinemascope screen), you would need for instance about 6 4645C subs (then the mains should be above, you need a raiser fo your seats then say row 2 at 40cm and three at 80cm so ears are better matching the height of the horns.) or 3 4675D or C and 3 subs 4645C. (given they all have a 65cm width). then you could fill the left empty space with lots of heavy duty acoustic foam. and of course all the wall behind them. they shoudl all be stacked against the wall. THX also recommands tilging-orienting the horns toward 2/3 of the seating area so youmight want to leave yourself the ability to do that rather than having the mains "blocked", impossible to adjust.
This would be a monstruous system and you certainly wouldnt need more than 500-800w per subs ! the room should be 7-8meters long, with bass traps in the corners, front side treatement, ceiling, diffract a bit in the surround area but not much since you would have 4 surrounds and 2 surrounds back likely.
you can see a pic of my ht in the gallery. so far i have only 2 18" gunners, one in corner, one in front middle or about. it had a tremendous on bass reponseat the seating. room modes already have diminished a lot. mains at single 15" woofies.
but that's already 3 15" and 2 18". we're approaching the sonic wall step by step.
I'm concentrating on a 1080p system hopefully as the sound is already blasting
Thanks again.
Okay, I thought the two 15" drivers on the 3632 array's were subs.........you're saying they aren't....they are in fact 'mains' and so I need further sets of 18" drivers to go beneath these.....(at least in an ideal world) :D

Well yeah, cost is one thing......the other is size. The 3632 arrays are already nearly 2 metres tall. Fitting in another set of drivers beneath these could get challenging. :eek:

I will certainly allow for flexibility in the way I mount the MF/HF horns so that they can be tilted or angled towards the audience.........that makes sense from the comments Ken has made too.

I'm also quite comfortable now about using one channel of the Q66 to drive the MF/HF section and the other channel to drive the 'mains'. I've got enough Q66's to take care of the three 3632 arrays if I do it this way....plus two more for the 4 surrounds.

Getting a whole other bunch of subs plus requisite amps is another thing though. At the very least I would need three subs (one under each 3632 array) but probably more from what you are saying. I don't doubt your advice or knowledge here Digital but at some point the realities of the wallet do bear some consideration. :(

The room was going to be 5-6 metres wide and 10-13 metres long by the way....

KenWH

07-07-06, 10:13 AM

The subs will probably need to be placed separately from the mains for best results.

Basically the 3632's bass section(the two 15'sa) needs to be as close to the mf/hf section as possible.

The subs on the other hand, depending on the room, could very well be installed a good ways from the 3632's. Corner stacking the subs in one corner will usually give you the most spl and extension. But that's certainly not written in stone.
In my room I find that placing the subs along a side wall gives me the best overall sound.

edit:
The reason subs can be positioned away from the mains is bass below around 80hz is fairly(not totally) omni-directional which means it's difficult for the human ear to localize where it's coming from.

By the same token...that's why the bass section of 3632 needs to be near the mf/hf...the bass section in the 3632 is used to play well into the mid-bass lower mid-range area and will be easily localized if it's not close to the mf/hf sections.

As to pricing...I'm not sure of JBL pricing down under but here in the states new JBL thx subs are actually pretty affordable and make a great BANG for the buck compared to most consumer grade subs.

Here you can get new 4645c's for around $1000 delivered and I got my 4642a for $1100 delivered. Of course you need good amps for these as they are passive subs. But one large amp bridged could easily drive two more subs.

Digital2004

07-07-06, 10:29 AM

hey guys :)
as Ken says very well, those are not subs indeed. best in the serie by far are the 4645C which can go to 22hz 0dB. imagine what means when it can handle without power compression around 800w clean (real watts, so 1600AB or 800digital, +/-).
they work better by pair :D :D . you gain another 5dB (!!!). add weight on them, like say 45lbs. you will hear the difference....
Myself i would have never go that big though for the mains! anything like the 3677 3678 or GKF 505 are more than enough. the former going to 60hz and the later to 40hz. (crossover point , below going to the subs as explained earlier).
Now if you plan larger than 4meters scope screen, ok, you could envisage the 4670D or 4575C (i much prefer these two models that Ken has).
I understand the $ impact. since you already spent on the 3632 and other stuff.

try also to think about a microperforated screen (or screenresearch but you need 2000ansi with such screen in 4meters, they EAT a lot of light),that fits the width of the room. the cinematic impact is gigantic (ok you wont see part of the speakers no more :) ).

An excellent system at raisonnable price is this:

3677 x3 (cut at 60hz)

8340A x 6 (cut at 80hz). Ken, they dont sound 'as good" as the wood predecessor but for home cinema, plenty good.

4645C x 2 (wire: 2x6 or 8sq mm), modify the connectors.

amp: QSC DCA 2422 for the subs + Velodyne SMS1 (which has onboard subsonic filters)

source: DENON 3806 (feeding the surrounds too) for AUDISSEY EQ AND INDEPENDENT CROSSOVERS.

mains power: QSC DCA 1644 for the main LCR.

converter: for future: GENELEC DIA8 8channels
Jocavi bass corners (22kg each !) x 2 or 4

llumpire

07-08-06, 12:05 AM

Has anyone mentioned the Meyer Sound Lab, EAW, SLS Audio or other self-powered theatrical speakers? Anyone have any thoughts on these competitors?

Kwikas

07-08-06, 07:53 PM

Originally posted by KenWH
The subs will probably need to be placed separately from the mains for best results.

Basically the 3632's bass section(the two 15'sa) needs to be as close to the mf/hf section as possible.

The subs on the other hand, depending on the room, could very well be installed a good ways from the 3632's. Corner stacking the subs in one corner will usually give you the most spl and extension. But that's certainly not written in stone.
In my room I find that placing the subs along a side wall gives me the best overall sound.

edit:
The reason subs can be positioned away from the mains is bass below around 80hz is fairly(not totally) omni-directional which means it's difficult for the human ear to localize where it's coming from.

By the same token...that's why the bass section of 3632 needs to be near the mf/hf...the bass section in the 3632 is used to play well into the mid-bass lower mid-range area and will be easily localized if it's not close to the mf/hf sections.

As to pricing...I'm not sure of JBL pricing down under but here in the states new JBL thx subs are actually pretty affordable and make a great BANG for the buck compared to most consumer grade subs.

Here you can get new 4645c's for around $1000 delivered and I got my 4642a for $1100 delivered. Of course you need good amps for these as they are passive subs. But one large amp bridged could easily drive two more subs.

Ken, this really explains things some more........thanks.

Can you tell me what your room size is and how far apart your LCR speakers are? I've no doubt I'll have to experiment some with the 3632's but I'm curious as to what you've found best in your set up. What size is your screen too by the way?

Basically, I can build the room around the system as I'm starting with a blank piece of paper.

I'll look to getting two 4645C's out of the USA. I'm already buying some JBL gear up there and I have friends in the freight forwarding business so my shipping costs are not too bad. I am hoping that two 4645C's will do the necessary.......from what you and Digital have said so far, it sounds as that number will be fine.

KenWH

07-08-06, 11:37 PM

My screen wall is 24-feet across and room depth 21-feet plus the irregular area in the back left corner. Ceiling height is 8.5- feet. Not an ideal shaped room by any means but it is what it is. ;)

My screen is a 16x9 format measuring 58 inches by 107 inches. First row of seats is 14-feet back second row about 18-feet.

There are some differing thoughts on speaker spacing but I've found a good starting point is for the left and right mains and the center of your main row of seats to roughly make a triangle with equal measurements for all three legs. With the center channel obiviously between the mains. I've found this to be a pretty good starting point for both movies and music setups.

For a mostly or all movies system you may find a more convincing front stage by placing the left and right as close to the edges of the screen or just inside the edges of the screen if your using a perf'd screen.

This placement can make the sound more tied into the on-screen action which makes the sound seem like it's actually coming from the screen. If your speakers are spaced too widely past the screen...some panning audio effects will be artificially wide sounding and not flow with action on the screen.

Right now my current "movie" setup is a bit compromised to allow for better placement of my Magnepan 1.6's that I use strictly for 2ch. music. Therefore I've had to move the left and right jbl's out a little further than I'd really like. As a result...I sometimes get the car or airplane coming out of the corner of the room effect. :o

As a side note...I glanced at a pdf file on the 3632's and I believe the mf/hf brackets that come with them will allow for some angle adjustment. So you should be able to dial-in those high mounted tweets fairly easily. :)

Kwikas

07-09-06, 03:32 AM

I'm still looking at building a baffle wall in front of the main wall and flush mounting the 3632's into it. Once I've got the MF/HF section angled correctly and the LCR placement sorted I'll mark out the positions. It will be easy enough to build a front wall with an upright lower section for pushing the LF drivers into and an angled upper section to accommodate the MF/HF drivers. I'll completely seal off the 'cut arounds' and sound deaden with the appropriate foam in behind. The MF/HF section has a flange around it with pre drilled holes which makes it easy to bolt into the wall. I want the fronts of these arrays to be flush and not to sit out in the room....the same as with current commercial installs. :)

At this stage I'm thinking to build a room 6 metres (20') wide, 11 metres (36') long and use a 4 metre (157") wide perf'd screen. If I put the L & R 3632's just inside the edge of the screen it means that I'll only have about 857mm (34") between the closest edges of the L & C arrays and C & R arrays. The 3632's are 762mm (30") wide........at that spacing they might to be too close....what do you think? I may have to put the L & R arrays out past the edge of the screen a little so as I can space them a bit more. I know I'll have to test this though...... :confused:

What about your rear speaker positions? How have you managed the placement of these?

Digital2004

07-09-06, 10:54 AM

with that size of front wall width, i'd do a 5meters cinemascope screen with a projector like the WD2000 from mitsubishi for instance (2000ansi lumens real) and an ISCO II lens.
that's still 17FTL more than SMPTE recs of 13FTL. (2000/114sq ft).
you would have no problem of spacing between speakers. and the field of view would be more cinematic (with the frame width, you'd have left about 40cm from screen edge till wall).
think HD :) . 1080i even on 720p and the ISCO on that size would blow you away.
Only condition is to have a MINIMUM 1500ansi lumens from the projector. Minimum.
especially if you go with a Screenresearch which EATS lots of lumens. more than the typical microperforated screens. dont baffle the subwoofers until you have made all tests of best
positioning the beasts.
on Dolby website i think there are technical guidelines for properly position the mains and surrounds (orientation, tilting, height). as this size of room is a small mini cinema already :)

KenWH

07-09-06, 11:21 AM

At this stage I'm thinking to build a room 6 metres (20') wide, 11 metres (36') long and use a 4 metre (157") wide perf'd screen. If I put the L & R 3632's just inside the edge of the screen it means that I'll only have about 857mm (34") between the closest edges of the L & C arrays and C & R arrays. The 3632's are 762mm (30") wide........at that spacing they might to be too close....what do you think? I may have to put the L & R arrays out past the edge of the screen a little so as I can space them a bit more. I know I'll have to test this though...... :confused:

Indeed 34" might be a bit close. Move them out past the screen. You can always make a grille to cover them.

What about your rear speaker positions? How have you managed the placement of these?

If I recall you plan to use wall mount surround units...if so Digital04 is more familiar with those and could probably give you better advise on placing them.

Commercial cinemas use "arrays" of surrounds. Since your room has a good bit of length, you may need to do the same, only in a smaller scale. In a nice long room such as yours you might do four units (2 on each side) for side surrounds and another pair on the back wall for rear center duty for 7.1 material.

Placing the surrounds will depend on if your going to have two rows of seats and which row will be the main(best optimized) row. I've found in ht environments that it's a bit of a challenge to get even surround coverage to multiple rows without compromising the sound field some. Especially using direct radiator speakers. Again Digital04 is more versed in using these so I defer to him ;)

I'm a big multi-channel music nut and to keep the tone even throughout the room I'm running 4670 floor-standers as my side surrounds. If you looked at my pics they were in the back corners...well I've since moved them to directly even with my rear row of seats and firing perpendicular (straight out) from the wall. The horns have a wide enough dispersion that it gives a really nice enveloping sound to both rows. Though the sound is a bit strong for the ones sitting on the ends. :p

I'm still deciding what to do for rear centers but i want to use the same components that are in the other speakers. I'm probably going to have to build them myself.

Kwikas

07-10-06, 01:43 AM

Hey Digital04,

Every time we talk, my screen gets larger and the weight of my wallet gets smaller. :)

Yeah, I CAN fit a 5 metre wide screen into the room but DO I REALLY WANT TO? :eek:

At the present moment I'm more likely to do what Ken suggests and move the L & HR out a little more. But I am still some way off getting this room built so I'm going to leave the projection issues for later.

By the way, what's the recommended minimum viewing distance for a 4 metre screen when using the WT2000? Can you tell me?

The reason I want to get the speaker system sorted out ASAP is that it's extremely hard to get JBL PRO stuff down here and when it does become available it's is ridiculously expensive. I got lucky and landed a couple of 3632 MF / FF sections for an unbelievable price. Since the AUS$ / US$ exchange rate isn't too bad for us right now, I'm wanting to get the rest of the speakers and JBL parts out of the USA as soon as I can.

I'm all set on using three 3632 arrays at the front and two 4645C's (or 4648'sa) as subs.........

But what about surrounds? I notice Ken is wanting to match his speakers and I understand his reasons.....particularly for multi channel music. He already has two 4670's also and just needs to get a couple more - or at least he needs the drivers. In my case, I don't have any surrounds what-so-ever.

If I match my surrounds with the 3632 array's (which are a LF: M115H-8A and a HF: 2418H-1), the only JBL speaker system that comes close is the smaller 3622N array. It doesn't have the MF section. But to use 3622's as surrounds would be an expensive exercise.

As Ken says I could go to a total of 6 surrounds with 2 on each side and 2 at the back or........I could just shorten the room and have 1 on each side. I thought that I might use the EV ZX-1's and simply fix them directly onto the wall.

I guess it comes down to what sort of surround sound stage I'm wanting. Since multi channel music is not really a big thing for me, I imagine timbre matching the surrounds isn't so critical.

Kwikas

07-10-06, 01:47 AM

Ken / Digital,

There was some discussion on PRO gear here too.......

http://www.avsforum.com/avs-vb/showthread.php?t=624127&page=1&pp=30&highlight=ZX1

Digital2004

07-10-06, 04:04 AM

Hey Digital04,

Every time we talk, my screen gets larger and the weight of my wallet gets smaller. :)

:D

Yeah, I CAN fit a 5 metre wide screen into the room but DO I REALLY WANT TO? :eek:

i would if have THAT large a room as you will/do. you'd be set up for 20years... :)

At the present moment I'm more likely to do what Ken suggests and move the L & HR out a little more. But I am still some way off getting this room built so I'm going to leave the projection issues for later.

By the way, what's the recommended minimum viewing distance for a 4 metre screen when using the WT2000? Can you tell me?

i would say first row at 3.5meters. it depends a lot on the screen perforations. if it's a Stewart's like (5%+ density) microperforated you sure can. make sure you test different screens before. have 3 rows, well spaced (leg room).at least 70cm between each seats.

The reason I want to get the speaker system sorted out ASAP is that it's extremely hard to get JBL PRO stuff down here and when it does become available it's is ridiculously expensive. I got lucky and landed a couple of 3632 MF / FF sections for an unbelievable price. Since the AUS$ / US$ exchange rate isn't too bad for us right now, I'm wanting to get the rest of the speakers and JBL parts out of the USA as soon as I can.

I'm all set on using three 3632 arrays at the front and two 4645C's (or 4648'sa) as subs.........

4645C are real subs/ 4648 are 'bass reinforcements' down to 35-40hz.

But what about surrounds? I notice Ken is wanting to match his speakers and I understand his reasons.....particularly for multi channel music. He already has two 4670's also and just needs to get a couple more - or at least he needs the drivers. In my case, I don't have any surrounds what-so-ever.

8340A or 8330 or those from QSC also. for home theater sound.

If I match my surrounds with the 3632 array's (which are a LF: M115H-8A and a HF: 2418H-1), the only JBL speaker system that comes close is the smaller 3622N array. It doesn't have the MF section. But to use 3622's as surrounds would be an expensive exercise.

don't, it's overkill. if you want to listen to SACD DVDA, get yourself 5 columns (TRIANGLE KLIPSCH BW DALI etc etc) in your living room. and a sub. positioned in a circle...

As Ken says I could go to a total of 6 surrounds with 2 on each side and 2 at the back or........I could just shorten the room and have 1 on each side. I thought that I might use the EV ZX-1's and simply fix them directly onto the wall.

yes, 2 Left 2 right 2 EX BACK. as i did.

I guess it comes down to what sort of surround sound stage I'm wanting. Since multi channel music is not really a big thing for me, I imagine timbre matching the surrounds isn't so critical.

see above.

KenWH

07-10-06, 09:20 AM

Can't much help on seating distance. I just know with my 13hd(16x9 native lcd) that 14-feet is about as close as you want to sit to a 118" diagonal screen. That said...the Mit's is dlp and should have a smoother image with far less screen door.

Surrounds...again hard to say. But in your case trying to do all 3632's would be quite the undertaking to say the least. :D

I use my room for probably at least 50% music and 30% movies and 20% hd satellite(hi-def sports mainly). Since music is my main use at the moment...i feel the overwhelming need to have all 6 or 7 speakers match. Especially after hearing how easy the non-matching RS-7's were to locate.

Now that hd dvd/bd is out...my room-use ratio may change a bit. ;) It's hard to go back to 480p dvd's after watching an hd movie via satellite...the new hi-rez dvd's look even better than sat. from what few demo's I've seen personally.

I just hope they start putting out movies I would actually want to own... :rolleyes:

mysphyt

07-10-06, 09:46 AM

Has anyone mentioned the Meyer Sound Lab, EAW, SLS Audio or other self-powered theatrical speakers? Anyone have any thoughts on these competitors?

I am currently using an all EAW Cinema Systems line up. I'm using the CB-153X LCR's and CR82FM surrounds. These are not powered models. The CB-153X's are pro cinema speakers designed for smaller cinemas, they have a 90 x 90 conical dispersion pattern that works well in the short throw home theater environment. I've gone through quite a few pro audio speakers in the past year looking for the right set for me (QSC, EV, JBL) and the EAW's are the one's I've chosen to live with. I like the three way design, IMO the 8" midrange reproduces voices with less sibilance and harshness than the two way systems with 12" and 15" LF/MF drivers that I've auditioned. The 15" LF driver in the CB-153x maintains authority in the mid and upper bass regions, crossed over to LAB12 v3 subs at 80Hz for subwoofing duty.

I've posted some more info and pics here. (http://www.myhometheater.homestead.com/ProSpeakers.html)

KenWH

07-10-06, 02:20 PM

mysphyt

07-10-06, 03:07 PM

mysphyt,

Looks like a great system. :)

How are you liking your ref50? I'm without decent processing right now due to a lightning strike. :( I've seen a few of these going fairly cheap on ebay and agon and was wondering how these sound. I remember back 6yrs or so ago that the ref30 was regarded by many as the pre/pro to have. I'm looking at the sher. p965, outlaw 990 and other similar priced new and used units.

Though I hate to spend a bunch of cash on a processor now cause within a year all the new hd audio formats will be common. I'll probably just buy a low-mid level receiver with pre-outs to tide me over for now.

Thank you,

Prior to the Ref50 I used a low-mid level Denon reciever with an Ebtech unbal/balanced converter to drive the system. The Ref50 with balanced outputs, a full feature set and cleaner sound was a huge step up for me. With that said, I'd think twice about buying the same model today (Series 1) as it has been superceded by the Ref50 S2 and won't support emerging formats.

Tim916

07-10-06, 05:44 PM

Do any of you guys have experience with Danley products? The SH-100 looks like it might make for a good HT speaker. The DTS-20 sub has gotten some attention over in the subwoofer forum.

http://www.danleysoundlabs.com/

Kwikas

07-20-06, 08:53 PM

Originally posted by mysphyt.
I am currently using an all EAW Cinema Systems line up. I'm using the CB-153X LCR's and CR82FM surrounds. These are not powered models. The CB-153X's are pro cinema speakers designed for smaller cinemas, they have a 90 x 90 conical dispersion pattern that works well in the short throw home theater environment. I've gone through quite a few pro audio speakers in the past year looking for the right set for me (QSC, EV, JBL) and the EAW's are the one's I've chosen to live with. I like the three way design, IMO the 8" midrange reproduces voices with less sibilance and harshness than the two way systems with 12" and 15" LF/MF drivers that I've auditioned. The 15" LF driver in the CB-153x maintains authority in the mid and upper bass regions, crossed over to LAB12 v3 subs at 80Hz for subwoofing duty.

mysphyt,
How are you managing your LF - MF/HF cross overs for the L / C / R speakers?

I'm going to be using EV Q66 pro series amps but these can't be fitted with crossover cards like the EV CPS series which are specifically designed for cinema use.

As Ken pointed out earlier, some of the newer Crown amps like their CT series can be retro-fitted with ScreenArray PIP modules. One of these modules is made specifically for the JBL 3632's but I'm not into buying another set of amps......

EV do make the Dx38 Sound System Processor which could be used......$$$$ perhaps! :confused:

Also, I'm interested to know more about the Behringer Feedback destroyer and Parametric EQ that you are using....your schematic shows it's hooked up to your centre channel amp and your subwoofer amp.....can you tell me more about its function?

Thanks.

mysphyt

07-21-06, 12:07 PM

mysphyt,
How are you managing your LF - MF/HF cross overs for the L / C / R speakers?

Just using the bass management of the B&K Ref 50 processor.

I'm going to be using EV Q66 pro series amps but these can't be fitted with crossover cards like the EV CPS series which are specifically designed for cinema use.

As Ken pointed out earlier, some of the newer Crown amps like their CT series can be retro-fitted with ScreenArray PIP modules. One of these modules is made specifically for the JBL 3632's but I'm not into buying another set of amps......

EV do make the Dx38 Sound System Processor which could be used......$$$$ perhaps! :confused:

Also, I'm interested to know more about the Behringer Feedback destroyer and Parametric EQ that you are using....your schematic shows it's hooked up to your centre channel amp and your subwoofer amp.....can you tell me more about its function?

Thanks.

The Behringer is currently doing equalization duty for the subs and center (lvery light on the center). It is connected in series between the processor and power amps. The equalization is primarily room mode correction for the sub and some HF compensation for the center because it is mounted behind fabric and the LR are not. It is an OK unit as long as you are careful to keep all your signals within operating limits.

What I'd love to have is a Lake Processor. (http://www.dolby.com/professional/live_sound/products/lake_processor.html) I'd use it on the L/C/R/SUB. It is up to 4 channels in so to do the full 7.1 would require 2. I'd also consider a Rane Dragnet DSP system or dBX 4800 DSP.

PTT

07-23-06, 03:22 AM

What do you guys think about three of these

http://www.djmart.com/jbl-3678-loudspeaker-system.html as LCR and 4 of these

http://lydrommet.ravn.no/artikkel/produkt/vis.html?id=15432

In a room 4 by 8 meters with some leaking. Is it possible to combine such a setup with commercial subwoofers like SVS pb12plus/2 or is it not recommendable?

thanks guys

all the best

PTT

Digital2004

07-23-06, 03:51 PM

PTT
hi
with experience, i would advise to go for full range front LCR. with JBL it's models like the 4670 4675C for instance. GKF it's 505 and Exclusive (2x15', 105kg).
it allows you the best possible home cinema bass set up: LCR in full range down to 30-40hz and the subwoofers doing the LFE + the <40hz.
It's important to have a good sound pressure (acoustic pressure) match that the LCR be big speakers, if you combine them with 18" gunners.
Otherwise, it's better the leave the LCR in "small" form (80hz for instance).
This is my next upgrade. Ken is doing the right thing. :)
I cut my 3677 at 50hz but their 50-80hz range pressure is not match to the 18'' subwoofers. There's too big a difference in pressure and there's thus a big drop in pressure in the 60-80hz zone because of this crossover. And we all know how important this zone is in film sound. in fact the 40-80hz zone is way more important than the 20hz zone. test for instance an explosion or a gun shot and cut the mains and then cut the sub. you'll lose a lot more by cutting the mains.

KenWH

07-23-06, 04:08 PM

Hi guys...just an update on my quest for proper rear centers. I'm about 80% done with building my "frankenstein's monster" rear centers.

Basically I've built a pair of wedge boxes 2.3cu.ft. in volume with medium fill. I stuffed a 2225h 15" woofer and a couple 4"x8.5" ports in each and tuning is around 50hz. The volume and port config was suggested over at a JBL forum.

On top will go a 2445 comp drivers sand 2385a lens on each. Xover point will be 500hz to match the rest of my speakers. Now in boxes this small I know it won't have the greatest bass extension but it should suffice.

I also replaced my damaged pre/pro with a Sherwood P965 which has an adjustable crossover. I'm pretty happy so far with the 60hz setting for the 4675's and 4670's.

Digital2004

07-23-06, 05:09 PM

hi Ken
the Sherwood has independent crossover ?
i would cut your main at 40hz or 35hz.

just did another test, LCR at 50hz and 80hz but this time i corrected the subs in the 50-63hz region ( a little boost to compensante from the crossover region losses + different acoustic output from the 3677).
no picture ! the 50hz cut is way better, because there's that bass wall in front of you and the subs go deeper because they concentrate on the infra and the amp gives all his power to the LFE + 50hz-20hz range. So, it's lesser evil than having the 3677 cut at 80hz.

BUT ! , again, the ideal is 3x double 15" mains LCR + 2-4 18" gunners :)
the BASS wall. very important. it also reduces room modes !
and if the front wall is on its left and right front heights made of subs only, +LCR twin 15", you probably have no more room modes in the bass and an incredible wall of bass + incredible unlimited headroom. but this also requres to properly treat the front wall completely, perhaps baffling the speakers and subs inside an acoustic wall.

PTT

07-23-06, 11:57 PM

Thank you very much mr digital. By the way do those speakers you mentioned need alot of space behind them, like most big hifi speakers does.

I have some experience with some rather big hornloaded 15" speakers and placing them to near the rear wall made them sound muddy /slow in the bass region.

But the JBL is probably made for placement near backwall?

Also I am confused by the crossover issues. Do I need an external active crossover ? Could I eventually use my Denon 3806 for such?

Thanks again this is very interessting thread. I would like to learn some more about this pro stuff. Seems like regular home theater is missing out on alot:-)

all the best
PTT

Kwikas

07-24-06, 12:10 AM

BUT ! , again, the ideal is 3x double 15" mains LCR + 2-4 18" gunners
the BASS wall. very important. it also reduces room modes !
and if the front wall is on its left and right front heights made of subs only, +LCR twin 15", you probably have no more room modes in the bass and an incredible wall of bass + incredible unlimited headroom. but this also requres to properly treat the front wall completely, perhaps baffling the speakers and subs inside an acoustic wall.

Digital, this is what I intend to do in my cinema. That is, build a full front baffle wall and flush mount the three 3632's into it..........with the MF / HF compression drivers angled downwards.

My only problem might be mounting the two 4645C's into the same wall. I'll probably have little space to fit them......particularly if they ideally should be underneath the 3632's. Do you think the 4645's will (could) work okay alongside the 3632 ScreenArrays?

I see that other people - including Ken, have mentioned that his subs sound better mounted against the side wall.....I'm going to have to experiment once the room is built.

Originally Posted by KenWH.
Basically I've built a pair of wedge boxes 2.3cu.ft. in volume with medium fill. I stuffed a 2225h 15" woofer and a couple 4"x8.5" ports in each and tuning is around 50hz. The volume and port config was suggested over at a JBL forum.

On top will go a 2445 comp drivers sand 2385a lens on each. Xover point will be 500hz to match the rest of my speakers. Now in boxes this small I know it won't have the greatest bass extension but it should suffice.

Ken, I wish I was as proficient and knowledgable. Anyway, where there's no appropriate level of skill, parting with money will have to suffice :)

I've been studying up on the 8340A's for surround duty and while I'm sure they'll be okay, I'm leaning more towards the AC2215/00's. This is because they have the same drivers in them as the 3632's and that's got to be a good thing..

Originally posted by mysphyt
What I'd love to have is a Lake Processor. I'd use it on the L/C/R/SUB. It is up to 4 channels in so to do the full 7.1 would require 2. I'd also consider a Rane Dragnet DSP system or dBX 4800 DSP.

Mysphyt, those look like great processors but don't you need to have amps with HD15 connectors to use them? I don't think the Q66's would work with any of these unfortunately.

I'm actually not sure securing any equalizers or crossovers right now because as Ken pointed out earlier, a good pre/pro may be able to handle all this. I haven't got my front end yet and wont be for a little while. I'll get this once the cinema is built - along with the projector.

The annoying problem down here though is that to get an equaliser or crossover when you need it means you'll be paying retail. A couple of good crossovers and equalisers (Rane & EV) have just become available to me at good prices and it's rare for them to come up......it's a kind of catch 22.

Kwikas

07-24-06, 12:55 AM

Guys..........

I've just found this......in terms of an outboard sound processor for the ScreenArrays (and surrounds)...........what about this as a unit?

http://www.jblpro.com/pages/electronics/active.htm#DSC260

Any ideas as to it's suitability for my intended setup? Thanks

Digital2004

07-24-06, 01:26 AM

Hi guyes

the 3806 is an excellent tool, this receiver has audissey EQ and independent crossovers. it will serve you perfectly. for instance crossover LCR at 60hz, surrounds 80hz.
or you can try all SMALL crossover at 60hz.
the speakers are all "front bass reflex" so you can push them against the front wall, that you will have treated acousticly of course. it's not compulsory to baffle wall the speakers though, especially the subs since you first have to experiment where ideally to place them against the front wall or as Ken did and as Tomlinson recommends often, to place them at mid point against the side walls (+/-).

as for external crossovers, i'm more familiar sort of with the XC3 LF3 SF3 from QSC that you plug into the DCA amps. very easy to use (sort of :) ). for bi triamp, subsonic cut, compensate for screen loss.

Kwikas

07-24-06, 03:07 AM

Digital,

Just to clarify, are you saying that with a good processor like the 3806, you don't really need need external crossovers like say a Rane 22B and/or equalisers? If that's the case, I'll look to get a unit like this when I'm ready.

Thanks for the advice about the front wall. I'm going to be building a room within a room so it will have a separate internal front wall anyhow...I may as well design it properly use it as a baffle wall.... :)

However, I can see that my subs may not be positioned up front.......perhaps more likely down the side.

Digital2004

07-24-06, 04:43 AM

hello
yes the 3806 can do front biamp and independent crossovers so for each channel independently (! like a Lexicon processor for instance).
be sure sur first launche the Audissey EQ setup as it's compulsory before you can adjust the crossovers FQ per channel.

make sure the front wall is heavy, like concrete (then add the acoustic treatment). it must be solid, to give full "support" to the front speakers in the lower frequencies.

test for the subs positioning in the room. thing is however than you ideally need three large front speakers if you want to start creating that "wall of bass", since your subs might be placed elsewhere (on the side walls for instance). you got to test the two possibilities (sibs on the side walls or subs on the front wall)) and see what gives best results.

Digital2004

07-24-06, 02:52 PM

what works as tested if seating area in middle of room: (idea is to get even bass at all rows):

subs front L or R corner + rear opposite corner (opposite diagonal corners)

subs at front mid side walls ( Tomlinson Holman likes that a lot)

full height subs L+R and along front wall (very expensive)

a sub at heach wall mid point (what you do Ken at least 1/2 of it :) )

a sub in each corner

in all cases accoustic resonators necessary.

Greg_R

07-24-06, 06:53 PM

Kwikas, you may want to change your text color. Those of us using the alternate AVS color scheme (light grey background) are getting headaches from the yellow lettering!

Kwikas

07-24-06, 08:17 PM

Hi Greg.

Thanks for advising me. My screen seems to show that my yellow color posts are the same color as all the others who have contributed here (including your message)..... :confused:

What about this?

Greg_R

07-25-06, 04:49 PM

Go into your profile and fix the settings...

Tom Brennan

07-29-06, 12:35 PM

I've used both Altec and JBL theater drivers and speakers in my hi-fis and HTs for many years and I prefer the Altec stuff. Modern JBL stuff sacrifices nuance and tonality for broad bandwidth, insane power handling and constant coverage, older JBL stuff often sounds better, mainly the woofers and horns not the compression drivers.

Best I had was a set of Altec A5 VOTs, next in preference were A7-500s. With their model 515 woofers and 1.4" 288 drivers the A5s have a little more heft and ease in the midrange than the A7s with their 416 woofers and 1" 802-902 drivers.

Of course Altec multicell and radial horns sound much nicer than JBL's (or anybody's) constant-directivity horns (IMO). The old Altec "Hollywood" tar-filled multicells are the finest horns I've heard, better than Edgar saladbowls even.

In my new house I'm using Altec 605 Duplex studio monitors as my mains, some A7-500s are in the garage awaiting new paint, then I'll move them into the HT and use the 605s as rears.

No doubt 515s will some day find their way into the 825 VOT cabinets and the 802-511s will someday be replaced with 288s on 1005 multicells, thus do A7s morph into A5s.

Kwikas

07-31-06, 06:38 PM

KenWH

08-01-06, 08:55 AM

Can any of you guys tell me what you think about using JBL AC2215/00's as surrounds rather than the 8340's? The drivers in the 2215/00's are the same as in my 3632 ScreenArrays.........

Also your thoughts on using one JBL 4642A sub vs 2 4645C's?

Crown and JBL have recently released the CDi series of amps specifically designed for JBL theatre speakers. In their recommended data for a system which is exactly what I want, they suggest using one CDi1000 amp for each of the 3632's (biamped), one CDi2000 amp for the 4642A sub (bridged mono) and one CDi2000 amp for six 8340 surrounds.

Now that I've finished my surrounds and hear how seamless the sound is...I totally suggest using surrounds that match the fronts as much as possible.

I can give you some insite on the subs your looking at also. I have a 4642a which I ran "stock" for about a year. Paired with a qsc plx1602 it is an excellent sounding sub. About two months ago I dropped in some 2242 drivers which are used in the 4645c's into the 4642 cabinent. I would suggest just going with two 4645c's as the drivers are a setup from the ones in the 4642.

Overall I have more output...deeper extension without losing any sound quality after doing the driver swap.

Kwikas

08-02-06, 08:25 AM

Originally posted by KenWH
Now that I've finished my surrounds and hear how seamless the sound is...I totally suggest using surrounds that match the fronts as much as possible.

I can give you some insite on the subs your looking at also. I have a 4642a which I ran "stock" for about a year. Paired with a qsc plx1602 it is an excellent sounding sub. About two months ago I dropped in some 2242 drivers which are used in the 4645c's into the 4642 cabinent. I would suggest just going with two 4645c's as the drivers are a setup from the ones in the 4642.

Overall I have more output...deeper extension without losing any sound quality after doing the driver swap.

Ken,

I can't get better advice than that. Actually, I suspected that the 2215/00 speakers would be better sounding than the 8340 surrounds in my system. I was pleased when I found that JBL actually make a cabinet that uses a couple of the same drivers found in the 3632's.......they should be a good match up. I'll run 3 pairs of 2215/00 surrounds using the EV Q44's. The EV Q66's can do duty on the 3632's.......

Great advice on the 4642A vs 4645C too - thanks. I'll go with two 4645C's......

Originally posted by Tom Brennan
I've used both Altec and JBL theater drivers and speakers in my hi-fis and HTs for many years and I prefer the Altec stuff. Modern JBL stuff sacrifices nuance and tonality for broad bandwidth, insane power handling and constant coverage, older JBL stuff often sounds better, mainly the woofers and horns not the compression drivers.

Best I had was a set of Altec A5 VOTs, next in preference were A7-500s. With their model 515 woofers and 1.4" 288 drivers the A5s have a little more heft and ease in the midrange than the A7s with their 416 woofers and 1" 802-902 drivers.

Of course Altec multicell and radial horns sound much nicer than JBL's (or anybody's) constant-directivity horns (IMO). The old Altec "Hollywood" tar-filled multicells are the finest horns I've heard, better than Edgar saladbowls even.

In my new house I'm using Altec 605 Duplex studio monitors as my mains, some A7-500s are in the garage awaiting new paint, then I'll move them into the HT and use the 605s as rears.

No doubt 515s will some day find their way into the 825 VOT cabinets and the 802-511s will someday be replaced with 288s on 1005 multicells, thus do A7s morph into A5s.

Tom,

Perhaps slightly off topic but what amps are you using to drive the Altec's may I ask? Did you - or do you, run pro amps with these? Given the history you've had with pro cinema speakers, I'm interested to know whether you (or anyone else here) can comment on something I've heard as regards the use of pro amps.

I have been told on more than one occassion that pro amps perform best when they're running hard - by that I mean at higher power output. Apparently, they can have a tendancy to falter or 'power oscillate' at lower volumes..........I'd be interested to hear what you may have found. I never heard this comment made by others on the forum when I was 'shopping' for my pro amps.....but perhaps they all run theirs at full blast........ :)

Originally posted by mysphyt
Prior to the Ref50 I used a low-mid level Denon reciever with an Ebtech unbal/balanced converter to drive the system. The Ref50 with balanced outputs, a full feature set and cleaner sound was a huge step up for me. With that said, I'd think twice about buying the same model today (Series 1) as it has been superceded by the Ref50 S2 and won't support emerging formats.

mysphyt,

Would you buy the ref50 S2 to replace your S1 and if you did, how much of the crossover and EQ could be handled by the ref50 S2? Would it negate the need for a Dolby Lake, DBX Drive rack or Rane etc?

Tom Brennan

08-04-06, 06:48 AM

"Perhaps slightly off topic but what amps are you using to drive the Altec's may I ask?"

I've used all kinds of amps----SS amps both "audiophile" and pro and both PP and SET tube amps. I've been at this horn speaker thing for more than 30 years so I've used lots of stuff. Best sound was Altec A5s bi-amped (REAL bi-amping with an active crossover) with 125 wpc SS below 500hz and 12 wpc 6bq5 PP tubes above 500hz.

IME prosound amps run fine at low levels and a couple of pals use QSC pro amps to drive large horn systems in the home and both systems sound marvelous.

I find the high power of pro amps not needed for my uses and I drive my HT with a regular Denon HT receiver with about 75-100 wpc or so. Another Altec horn system in the living room is run by a 12wpc PP tube amp (6bq5s again) and a third Altec system in my music room is run by a 30wpc Teac "Tripath" chip-amp.

All three systems sound great to me. The only really "bad" amps I ever had were a Dynaco 120 and a 200 wpc Peavey prosound amp, the Peavey sounded especially bad, like a Skilsaw.

Kwikas

08-06-06, 07:52 AM

Thanks Tom.

I'm going to be running Q44's and Q66's as I explained in an earlier post. I think the biamped Q66's will be way overkill for the MF/HF sections of the 3632 ScreenArrays but since the Crown DSi1000 (biamped) is recommended for these speakers by Harmon pro, who am I to argue? :)

http://www.crownaudio.com/images/apps/cinema02.gif

I also notice in this diagram that one DSi2000 is used to run ALL surrounds. I'm not sure how this is achieved.....can anyone advise? My idea is to use one amp for each set of surrounds........which means three amps in total.

I'm looking very closely at the B&K Reference 50S2 preamp for the front end. But I also need some help on figuring out how I can hook up the six JBL 2215/00 surrounds to it. I can see that it handles four surrounds okay but I'm not sure how to get the extra two wired in........

http://www.bkcomp.com/ref50.asp

Can any one offer up advice on this....? Digital??

noah katz

08-06-06, 02:55 PM

"I can see that it handles four surrounds okay but I'm not sure how to get the extra two wired in........"

What signal are the extra surrounds getting?

I use two pairs of (different) side surrounds, one pair are 4 ohm each, the other 8.
The former are wired in series and the latter in parallel to my receiver; works fine.

Kwikas

08-07-06, 12:21 AM

What signal are the extra surrounds getting?

Noah, the extra surrounds will get a SSL & SSR signal.

I think I've sorted out a way to do this......should have looked at the amps a bit more closely.

The EV Q's have another L & R signal 'output' on the back of them which can take the incoming feed and direct it to another power amp.

So, L&R signal from the B&K into one amp for one set of SSL & SSR speakers, and then out of the back of the same amp directly into another amp for the additional set of SSL & SSR speakers.

That should do it.........

wcaughey

12-23-06, 03:04 PM

KenWH

12-23-06, 03:50 PM

I had a question about the pairing of jbl pro speakers in home theaters...

Earlier in the thread 8340A surrounds are recommended with the 3677 LCR channels. Would there be a negative to using the 8330A surrounds instead?

Just some quick benefits I'd see is more horizontal & vertical coverage (110 degrees horizontal,105 vertical), some saved money, and more saved money on amplifier power (their specs on the jbl site show them to be able to handle 400watt peaks), and a slightly broader freq. resp.. I could go comfortably go with crown 402ds instead of bumping up to the 602d's to maintain clarity with the 150watt increase. Also the 91db sensativity seems sufficient for any smaller room (<5000 cubic feet) compared to the 96db of the 8340A, especially with the closest seats in rows to them a small 1.5m (4feet).

For a room 21' deep and 19' wide, (I am planning on using a set of surrounds for each row (2 rows total), as well as 2 for the rear channel. Are the 8340A's really necessary or is there no problem using the 8330A's?

Imo the 8330's would work fine. Neither the 30's or 40's are likely going to be perfectly matched tone wise to the 3677 anyway. So for the reasons you state above the 30's would likely work out better for you. Being that your going to be sitting much closer to the surrounds(plus your planning to have two sets for the sides)...their lower sensitvity probably won't be much of an issue.

All my surrounds use the same horn and woofers, and roughly the same sensitivity as the front LCR(see avatar ;) ) and I have to cut the surrounds way back or they over-power my LCR.

edit:
The one thing that may or may not be noticeably between the 8340's and the 8330's is the compression driver/horn in 40's may sound a bit better with the 3677. I can't really say as I've not heard the JBL surrounds.

Curt Palme

12-23-06, 07:21 PM

Right now I'm using a Community rig for my left and rights, the SBS 25 for bass (2 X 15") and 3 way 12" for mid highs. I had smaller Community speakers for centerchannel, but they were horrible.

It's got lots of balls, esp with the Community processor, but isn't very HiFi. I'll be switching out to EAW speakers soon. I've got 4 channel Inter M amplifiers in the rack (www.inter-m.com).

The only reason I'm using these is because they were free. I also want to try Martin Logan electrostats that I've got sitting in the corner, but no time, no time...

Lots of pro audio gear sounds great in the home. If I could find some minty JBL 2225s, 2205s, slot tweeters and the nice horn mids, I'd be very happy. One unsung horn that sounded very nice was an old early 1980s Fostex one. I don't know the model number, but I do remember that the horn was all wood construction, and sounded a lot nicer than a bunch of the fibreglass counterparts.

KenWH

12-31-06, 01:13 AM

TSHA222

01-02-07, 11:03 PM

I use JBL commercial cinema speakers as I have a fairly large room. My setup is described in the 2.35 CH thread Alan maintains in another area and I have some pics of the theater under construction and some after pre-completion (it will never be FULLY completed!!) I just wanted to add that the speakers have really shown their worth since I installed HDDVD and Blu Ray players. I feed the 7.1 analog outs into my Arcam AV8 multi-channel input (with use of a switcher of course) and you can tell you are listening to something other than your normal HT setup.

KenWH

01-03-07, 06:34 PM

wcaughey

02-01-07, 10:25 PM

ken, thanks for the heads up...I hope it's still not too late :-P

Kwikas

03-19-07, 02:47 AM

Ken & TSHA222.....you guys still here??? Are you using electronic crossovers for your fronts and if so, what are they?

Kwikas

03-19-07, 03:20 AM

...............I'm going to need 3 in 6 out for the three ScreenArray's.........

KenWH

03-19-07, 09:11 AM

...............I'm going to need 3 in 6 out for the three ScreenArray's.........

On my fronts I'm using a DBX 223xl (2way) and a Behringer cx3400(as a 2way) for my center. For amps: Each front main runs off separate QSC ex1600's and the center runs off a QSC plx1602.

Going with active x-overs made a BIG difference for me over the jbl passives as the passives didn't have enough hf attenuation. Now I can really dial in the mid-bass from the woofers nicely with the horns.

For now I'm still running my side and rear surrounds with passive jbl x-overs but I did add a 16ohm adjustable attenuator on the horns...not the best solution but it improved the sound a good deal imo.

All that aside...If I had the money invested in my speaker system like you Kwikas I'd probably spring for the DBX driverack units that have presets for the JBL cinema speakers pre-programmed. :D

Kwikas

03-22-07, 09:36 AM

Originally posted by KenWH....
All that aside...If I had the money invested in my speaker system like you Kwikas I'd probably spring for the DBX driverack units that have presets for the JBL cinema speakers pre-programmed

Yes it probably makes sense but they cost a lot and once set, you're unlikely to touch them again. Plus, there seems to be a whole heap of features that I'd never use......I guess HT use for these things is a kind of 'tune and forget' install

The driverack 260 doesn't have factory presets in it for the 3632's I don't believe. So I'd need to go for the 480....$$$$$$$ :eek:

I was looking at the 223xl's like you have. They seem to be good value for money......I'd need three but it's way less cost than one 480...

KenWH

03-22-07, 10:48 AM

Hey Kwikas,

I was thinking the screen arrays were 3-way's...that's why I was suggesting the driverack units. I went over to jbl's site and saw that the arrays are 2-ways instead...sorry about that. :o

For a cost effective 2-way the dbx 223xl's are hard to beat...the regular 223 uses 1/4" in/outs instead of xlr so if you don't need xlr ins/outs the 223 is a bit cheaper.

mysphyt

03-22-07, 01:51 PM

...............I'm going to need 3 in 6 out for the three ScreenArray's.........

I'm using a Behringer DCX2496 ULTRADRIVE PRO digital crossover on my three front EAW Cinema speakers. It is a 3 channel in, 6 channel out device with parametric eq on each channel.

KenWH

03-22-07, 04:05 PM

I'm using a Behringer DCX2496 ULTRADRIVE PRO digital crossover on my three front EAW Cinema speakers. It is a 3 channel in, 6 channel out device with parametric eq on each channel.

I tried one of those on my l/c/r and I liked its flexibility and fairly simple interface.
I also liked that the x-overs,eq's, etc. for the front three channels were all housed in one unit making adjustments very easy to do. Unfortunately one channel on the dcx had a bad hiss/distortion in it so I sent it back...in fact thats when i decided to swap the dcx for the dbx 223xl. I have a couple different products by behringer and for the most part they are all nice units for the money.

If you get a good one and it works properly, the dcx would be an excellent way to go.

W.S.

03-24-07, 06:33 PM

After many years of blowing my hard earned cash on high end home audio equipment to no end I decided that enough is enough with (so called) high end audio equipment. Don't anyone get me wrong the high end stuff looks great and sounds pretty but hasn't satisfied me in the reliability department. I was burning anywhere from 2-4 amps a year and many more speaker systems. I had to try something radically different. I packed up all my remaining high end gear (still have it in storage) and I went pro audio. I haven't looked back going on 3 years and counting. The sound quality is better than any of the high end stuff I had before this and the power is so incredible that powering 1 speaker with 1 channel of a 2 channel pro amp made me exit the premises not just the sound room. So now I'm running 10 Yorkville AP4040 pro amps powering 10 Yorkville Elite LS1004 subwoofers , 6 Yorkville Elite L804 loudspeakers, and 4 L704 Yorkville loudspeakers. That's just for sound reproduction. To get the most out of my pro setup I complimented it with pro analogue and pro digital processing equipment (mixer analogue/ mixer digital/ ad da converter/ digital eq / compressor/ line eq....) . It all works simply fantastic and it makes modern movie soundtracks and music cd's sound phenomemal and the older (not so great sound mixes) very good indeed. I never expected such flexibility but now I know this is possible. So lately when I read articles on the new sound formats that are coming I'm not as interested in them anymore even though I understand why they are necessary. Not everyone can install a couple tons of audio gear in their homes. But if you can? Do it! You'll be blown away. :D :D

Digital2004

05-09-07, 01:04 PM

WS
do you have photos of this mighty set up ?

Kwikas

05-15-07, 09:54 AM

Originally posted by mysphyt
I'm using a Behringer DCX2496 ULTRADRIVE PRO digital crossover on my three front EAW Cinema speakers. It is a 3 channel in, 6 channel out device with parametric eq on each channel.

I'm considering the Behringer......a Sabine Navigator 3600.....or a Xilica DCP 3060........all of which have 3 in 6 out.

A person here is selling two new Altodrive 3.2 units that could be of interest. These are at a good price - well below the Sabine & the Xilica and just below the Behringer. I'd have to get both though and I'd prefer just the one box. I also don't know much about the Altodrive and I can't find too many user comments when I google it.......perhaps it wasn't that common.......or that good... :(

Cam Man

05-15-07, 11:01 PM

KenWH

05-15-07, 11:55 PM

Ken and others,

How are you or did you handle time alignment in your L/R stack? Typically, the cinema processor has time alignment for the compression driver and LF section. From what I hear, that is pretty critical.

From my limited research I've found:
Basically since mine are all two way's with a low 500hz crossovers the time alignment is a bit more flexible/forgiving than some of the big 3-ways in this thread. Jbl has a schematic for the 46xx series showing where the horns should be physically mounted on the woofer enclosure thus getting alignment in the ball park. Beyond that I've really not gotten more into it. From what I understand(might be wrong) when it comes to mounting horns it is the area where the throat opens into the lens which needs to be fairly close to the same vertical plain as the woofer cones. For example I followed JBL's schematic for my 4675's(ones in my sig with the large baby cheek lens) and the front of the lens is several inches closer to listener than the woofers. It looks a bit odd but that's the way it's supposed to be. :p

Now I can see the large(TALL) multi-way screen arrays being a nighmare since they are designed with the lens and woofers all on the same vert. plain. So yes they'd need a speaker controller like a dbx driverack etc. I believe the dbx gear has all the alignment parameters already preprogrammed.

Summer Baez

05-16-07, 12:05 AM

.. it's not often home theaters are equipped with the big stuff...

If I was starting a home theater from scratch I would use pro speakers. When one come to home theater from audio it make sense to keep and use old audio speakers for home theater after an upgrade. Home theater does not require audiophile grade type of speakers.

KenWH

05-16-07, 12:19 AM

I sold a full 7ch Klipsch rf-7' setup in order to buy my jbl's. I also had a pair of Magnepan 1.6's I ran for critical 2ch. However I soon sold the maggies to as I just kept spending more and more time with the JBL's. The large horns that can run all the way down to 500hz sure do a darn nice job with the mids...the only thing I felt the maggies did better was the uhf's as the jbl's rolloff pretty quick around 18k hz's. The highs have improved some since changing over to a denon 2807(using it as a pre/pro only) as the auto eq in it has opened up the highs quite a bit.

Curt Palme

05-16-07, 12:19 AM

I'm considering the Behringer......a Sabine Navigator 3600.....or a Xilica DCP 3060........all of which have 3 in 6 out.
(

To me, Behringer is low end garbage, I'll never deal with any of their product. I pulled a few pieces apart to see how it was made, that was enough for me. I've installed a Xilica 3060 in an arena. It worked well. Haven't used the Sabine, but generally it's decent stuff.

Kwikas

05-16-07, 03:02 AM

Originally posted by KenWH
Now I can see the large(TALL) multi-way screen arrays being a nighmare since they are designed with the lens and woofers all on the same vert. plain. So yes they'd need a speaker controller like a dbx driverack etc. I believe the dbx gear has all the alignment parameters already preprogrammed.

Ken, I'm still checking on this but I believe the alignment parameters for the 3632's are only to be found in the dbx 4800.......$$$$$$'s.......... but if someone can tell me different then I'd like to know. However, even if the dbx 260 (including the PA version) has them, I'd still need two units and that's more expensive than one Xilica 3060 or a Sabine 3600.

Ashley also make a 3 in 6 out too and I've heard good things about their processors so I guess this is another one to consider.

Smart Technologies released their TCX 650 for biamped L/C/R. Even though it's a commercial unit, it should work okay. However, they don't make them any more and finding one would be more difficult than buying any of the ones above.

Cam man is right. This is a critical matter. But I think any of the ones we've talked about here can handle it.....including the Behringer.

It's a pity that Harmon Pro haven't released a 3 in 6 out DBX specifically for cinemas using JBL biamped fronts. I guess they've covered this off by putting the crossovers into their Crown amps. Maybe the Cinema market just isn't large enough on its own to warrant another dbx driverack.....and I'm certainly not swapping out my EV Q66's to buy a heap of Crown DSI's.... :eek:

Originally posted by Curte
To me, Behringer is low end garbage, I'll never deal with any of their product. I pulled a few pieces apart to see how it was made, that was enough for me. I've installed a Xilica 3060 in an arena. It worked well. Haven't used the Sabine, but generally it's decent stuff.

Thanks for the info re the Xilica. It's always good to get feedback from an actual install. How as the interface? Was it simple to use? The Xilica is certainly high on my list.

Curt Palme

05-16-07, 10:51 AM

THE only problem I ran into was finding a RELIABLE USB to 9 pin serial adapter. This is a common issue with computer controlled sound equipment when you don't have a laptop with a 9 pin connector on it..:(

From what Bose told me, Microsoft only released a non USB software platform for manufacturers to write software on a long time ago before USB was popular. As a result, every manufacturer that I dealt with from Bose to Mackie to Crown had a 9 pin serial port to connect to. Finding a reliable USB to serial converter is a royal pain. I ended up with one that needed to be booted up 6X or so, but once it communicated with the device, it was solid.

As with all this computer controlled stuff, work with it in the shop before installing it. It saved me a few hours of dinking around in the field, as I installed it at an arena 18 hours away from me (in Kitimat, go Google that city..:))

As for the Xilica software, yes, it's pretty decent. As I said, play with it on the bench in a simple 2 channel setup before you install it permanently so you know what it does ahead of time.

Cam Man

05-16-07, 11:43 AM

Seems like the alignment would not be terribly difficult to handle if you had the tools to measure and adjust time precisely. I use the Ashly Protea digital parametric EQs. I would think that you could use a pair of channels for each stack in a biamped system. The delay for each channel of the Ashly is in very small increments, therefore permiting fairly precise alignment if you can disable each driver while measuring the other. Still, not cheap.

Has anyone tried any of the Klipsch pro cinema speakers?

Kwikas

05-18-07, 10:19 AM

Originally posted by Curt
THE only problem I ran into was finding a RELIABLE USB to 9 pin serial adapter. This is a common issue with computer controlled sound equipment when you don't have a laptop with a 9 pin connector on it..

That's what is so good about this forum. Where else could I find that out until it was too late.....thanks for the info.

Originally posted by Can Man
Seems like the alignment would not be terribly difficult to handle if you had the tools to measure and adjust time precisely. I use the Ashly Protea digital parametric EQs. I would think that you could use a pair of channels for each stack in a biamped system. The delay for each channel of the Ashly is in very small increments, therefore permiting fairly precise alignment if you can disable each driver while measuring the other. Still, not cheap.

The Ashly stuff is good. What model are you using....is it a 3.24cl? Are you using a PC with this or tuning it through the front panel?

Originally posted by Digital2004
Dont bridge: add subwoofers, send them clean 700-800 REAL WATTS(digital amps or Powerwave) and add subs if you dont have enough . Placement of subs is PARAMOUNT ! then treat the corners, have a stadium/raiser with seats, it helps a lot cutting the parallelisms induced room modes too.(but it's not enough, corner treatment AND placement of subS (plural!) is KEY.
And last but not least : independent bass management !

Digital, I haven't purchased the sub(s) yet....I was considering JBL 4645C(s) or a 4642A. However, I'm starting to think more about an IB arrangement with 15" drivers.......it might work out well considering the room is going to be built (we've just moved house) and they could be placed in a row along the bulkheads at the front and back of the room.......

Kwikas

05-18-07, 10:20 AM

..............I'll be using a K2 for sub duty. My understanding is that it's easier to drive subs in an IB set up rather than a ported or fully enclosed box......

Cam Man

05-18-07, 07:58 PM

The Ashly stuff is good. What model are you using....is it a 3.24cl? Are you using a PC with this or tuning it through the front panel? 4.24PS using the (laptop) PC control software.

wcaughey

05-24-07, 04:20 AM

Question about those jbl pro 3677s...the frequency response they list with the +/- 3 db runs from 45-12k....the -10 db rating is 40-20k.

I understand the 45-12k +/- 3db well enough, but is there a real drop off with 12k-20k frequency material? Or does this mean that sensitivity just drops off from large headroom 99 db to a lower number (probably like 89 or something)...Can this be compensated for via EQ by softening the 40-12k?

Anyone have any experience with the 3677s?

KenWH

06-01-07, 04:28 PM

Kwikas,

Hows the processor hunt going? Have you looked at the BBE ds48(4in/8out)? As far as pricing goes it slots in between the Behringer unit and the low end DBX driverack units. I'm seriously back in the market for one of these type of processors.

I'm considering the Behringer......a Sabine Navigator 3600.....or a Xilica DCP 3060........all of which have 3 in 6 out.

A person here is selling two new Altodrive 3.2 units that could be of interest. These are at a good price - well below the Sabine & the Xilica and just below the Behringer. I'd have to get both though and I'd prefer just the one box. I also don't know much about the Altodrive and I can't find too many user comments when I google it.......perhaps it wasn't that common.......or that good... :(

Kwikas

06-05-07, 03:21 AM

Originally posted by KenWH
Hows the processor hunt going? Have you looked at the BBE ds48(4in/8out)? As far as pricing goes it slots in between the Behringer unit and the low end DBX driverack units. I'm seriously back in the market for one of these type of processors.

Ken, I've just secured a BSS 9088 Soundweb processor......8 in 8 out. It's more than I need but I got it at a good price (as much as one can get a good price on BSS Soundwebs that is)...... :eek:

I'm now starting to get into finalising the speaker purchases .......I've presently got two 3632 ScreenArray HF/MF tops so I'll be getting another top shipped out from the USA shortly. That will have sorted the front three HF/MF sections at least.

I'm debating about the bottom LF sections. Some cinema's run full 3632 ScreenArrays utilising the 3639 LF enclosures. These use 2 x M115H-8A's. Others run different LF sections like 4647A's utilising 1 x 2226H drivers. While others mix the 3632 tops with 5641 enclosures......thus.......

http://www.jblpro.com/pressroom/august06/pacificsoundwaves.html

Any recommendations here? It probably doesn't matter too much although a smaller LF cab like the 4647A would get the 3632 HF/MF horns down closer to the floor than a 3639.

I'm debating surrounds too..... either six 8330's or six 8340's. I was going to consider matching the surround drivers with the front drivers like you have done but my set up will almost be totally for movies so it's not as critical. Any comments on these models?

I'm leaning more towards the 8330's because of the coverage. They are less efficient than the 8340's but with EV Q66's powering them I doubt this is going to matter a whole lot.

KenWH

06-05-07, 09:23 AM

Ken, I've just secured a BSS 9088 Soundweb processor......8 in 8 out. It's more than I need but I got it at a good price (as much as one can get a good price on BSS Soundwebs that is)...... :eek:

I'm now starting to get into finalising the speaker purchases .......I've presently got two 3632 ScreenArray HF/MF tops so I'll be getting another top shipped out from the USA shortly. That will have sorted the front three HF/MF sections at least.

I'm debating about the bottom LF sections. Some cinema's run full 3632 ScreenArrays utilising the 3639 LF enclosures. These use 2 x M115H-8A's. Others run different LF sections like 4647A's utilising 1 x 2226H drivers. While others mix the 3632 tops with 5641 enclosures......thus.......

http://www.jblpro.com/pressroom/august06/pacificsoundwaves.html

Any recommendations here? It probably doesn't matter too much although a smaller LF cab like the 4647A would get the 3632 HF/MF horns down closer to the floor than a 3639.

I'm debating surrounds too..... either six 8330's or six 8340's. I was going to consider matching the surround drivers with the front drivers like you have done but my set up will almost be totally for movies so it's not as critical. Any comments on these models?

I'm leaning more towards the 8330's because of the coverage. They are less efficient than the 8340's but with EV Q66's powering them I doubt this is going to matter a whole lot.

Sounds like your well on your way to a knock-out system!! :D
I also looked at the bss units...very nice units indeed.

I found a bbe 4/8 unit on ebay last night at a good price so I pulled the trigger on it. If it sounds as good as the dcx I tried earlier(minus the problematic channel) I'll be more than happy. I just couldn't see spending more on a processor than I did on my speaker/sub setup(I bought all my speakers used from a theater supply company). :p

As to your LF cab dilemma(poor guy ;) )...one obvious thing is the efficiency of the two designs. The dual woofer box at 4ohm will yield around 6db or more of sensitivity over the single woofer box. Either way the mf/hf sections will need some attenuation but the dual woofers would reduce the amount needed somewhat.

One last thing...when you get all this gear assembled we need pics!!!

Take care,
Ken

Solfan

06-05-07, 06:20 PM

I've got two of the original MCA/Cerwin-Vega Earthquake subs. They've been in the garage for years, my new house couldn't accomodate them [4'x4'x22"].

I was running them in my last house, the output is unreal and relatively clean as long as a REAL steep slope is used. And they must have solid room corners to load into.

I built a 48dB/octave 25hz low-pass filter for them but never had a good listening room to test it.

Otherwise, I'm a long-time user of old-style EV horn stuff, still cherish the T-25 and T-350 combination. :)

Kwikas

06-06-07, 08:56 AM

Originally posted by KenWH
As to your LF cab dilemma(poor guy )...one obvious thing is the efficiency of the two designs. The dual woofer box at 4ohm will yield around 6db or more of sensitivity over the single woofer box. Either way the mf/hf sections will need some attenuation but the dual woofers would reduce the amount needed somewhat.

Yes...understand your point here.........in reality I think it's going to come down to what pricing I can get on either three 3639 cabs or three 4647A cabs . Attenuation issues aside, price is probably going to be the determining factor. There might be some audible difference between these two boxes but that would be extremely difficult for me to test....and probably not worth worrying about.

One last thing...when you get all this gear assembled we need pics!!!

I was planning to build a dedicated HT room at our last place but we sold it just recently. We've just had twins arrive into the family and the previous house was too small........the project is still happening but it's going to take more time now unfortunately. :(

Originally posted by Solfan
I've got two of the original MCA/Cerwin-Vega Earthquake subs. They've been in the garage for years, my new house couldn't accomodate them [4'x4'x22"]. I was running them in my last house, the output is unreal and relatively clean as long as a REAL steep slope is used. And they must have solid room corners to load into.

YIKES!! Yeah, you really need a dedicated room when you're running this kind of gear. For subs I'm looking closely at the JBL 2242's like Ken has or running an IB set up with 15's. The subs are kind of the last piece of the speaker jigsaw for me and I need to do a little more research into this. There seem to be a lot of paths you can take.............. :confused:

Solfan

06-06-07, 10:33 AM

Some of these PA style direct radiator subs can be coaxed into fantastic infra-bass house shakers by suspending them a few inches off the floor, aiming downward. :D

dirtyharriett

06-13-07, 08:36 PM

Well let me start by saying that I have been in this wonderful hobby for over 20 years. I am currently well into the process of installing my twin manifold under the floor IB sub system. It has 8 18" drivers driven at 5000 watts (2500 @ 4 ohms per manifold). I have been told that my IB system is going to overpower my current M&K MX5000 THX speaker system (has two MX-5000 subs... was 13K back in the day). In researching a replacement speaker system I have absolutely decided on a JBL pro cinema system (MANY, MANY thanks to KenWH for the help you have given me). I am planning on putting the LCR and 2 subs behind a 160" AT screen. The horns on the 4675C's make them a little too tall to fit behind the screen and the JBL sales rep I spoke to said for dispersion reasons concerning my room size I should use the 4670D's. My room is not as big a KenWH’s.. I really hate that because those 4675's with that huge horn look so much sexier but that's the breaks. I plan on putting 3 4670D's up front along with 2 4642A's (in between the LCR's). I am planning on using 4 JBL 8340's for the surround speakers. I simply don't have the room for anything larger like KenWH is using. This arrangement along with my MONSTER IB sub system should give me a pretty good bass response ... I HOPE!!! I have decided to go with a few DBX Driverack 260's for the speaker management systems. This speaker arrangement will be powered by a selection of 12 QSC amps as described below. My room is only 13.5' by 21' and has a two tier seating arrangement. The equipment is held in a twin stack Middle Atlantic rack system that is neatly tucked away under the 2nd tier seating area at the bottom of the stairs. Overall the room should look awesome when we finish the HT remodeling. The thing that REALLY bugs me is the lack of space for larger surrounds... especially on the sides.

LCR's
3 x JBL 4670D's Bi-Amped with 6 QSC RMX 1450 amps bridged to 4 ohms to yield 1400 watts each (obviously 2 amps per speaker)

Front subs
2 x JBL 4642A Amped with 2 QSC RMX 2450 amps bridged to 4 ohms to yield 2400 watts for each sub

Surrounds
4 x JBL 8340A Amped with 2 QSC RMX 2450 amps stereo at 8 ohms to yield 500 watts per channel

IB sub system (manifolds are made to hold 6 drivers each... I have the 4 extra holes plugged at this time. It will however allow expandability for up to 12 18" drivers)
8 x FI CarAudio 18" Q18 drivers Amped with 2 QSC RMX 5050 amps bridged to 4 ohms to yield 5000 watts each (The Q18 drives are custom wired for IB sub system use and have an insane Xmax of 27mm) The 2 QSC RMX 5050 amps will be replacing EP2500 amps...

equipment list (the ones I'm NOT in the process of replacing ASAP)

projector JVC DLA-RS1 on 155" 16.9 screen (I LOVE THIS PJ!!!)
Onkyo TX-NR905 (on order... I'm waiting)
HD DVD Toshiba HD-AX2
Blu ray Sony PS3
Lumagen RadianceXD (on order... I'm waiting)

After room modifications are complete...
SMX 160" 2.35 AT screen with CIH masking system

Will need to join HTAA (Home Theater Addicts Anonymous) ASAP... ha, ha!!!

mysphyt

06-13-07, 10:25 PM

dirtyharriett,

Sounds like a sweet set up, I think you'll be very pleased....

KenWH

06-14-07, 09:22 AM

dirtyharriett

06-14-07, 09:44 AM

Hi Nicole,

I was happy to help. :) It's going to be a killer setup when your done!!!

The one other suggestion I can give to anyone running prosound amps with fans(especially if your running 12 ;) ) is to mount them where you won't here the fans as they can get loud. It's no fun hearing fans drone during the quite passages in a movie.

Ken, fortunately for me since my rack system is UNDERNEATH the second tier seating area there is a tremendous amount of sound isolation and so far you can't hear a peep. I have a large fan down there to help keep things cool (going to be installing a small A/C unit soon) and several items with noisy fans and so far... SILENCE. Even my projector is sound isolated by projecting throught the wall of one of the up stairs bedrooms. So far... so good with that issue. Thanks for the advice though. I have to admit that I am salavating at the thought of getting to hear your system. I'll have to bring a few IV bags of fluids just to make sure I don't dehydrate from all the drool... ha, ha!!!

coldmachine

06-14-07, 10:49 AM

Genelec 3xx full 7.1 system with twin subs. First audio tests tomorrow, full install next week.

dirtyharriett

06-14-07, 02:09 PM

Well today I went down the road to my local Pro equipment shop and shared the good news that I will be spending a horrid amount of money with them on QSC amps. I talked to the manager about QSC amps for a while and he said that in order to be competitive ALL amp manufacturers are generous with their amp specs these days. With this info in hand I decided to make a few changes on my equipment to buy list. I am replacing the QSC RMX 1450's with the 2450's and instead of 2450's on the subs I will go with the 5050's. After adding up the RMS rated wattage on my updated equipment list I was shocked to see that the wattage yield will be 30,200 watts. Man this thing is going to ROCK the house... I HOPE!!! I purchased my first DBX Driverack 260 on ebay last night and got a great deal on it! My custom manifolds should be ready to pick up on 6/19 and I purchased my first QSC RMX 2450 today. The ball is starting to pick up speed on this baby. I can hardly wait till the IB system is installed. I should be able to hear the first sound tests within a few weeks if all of the equipment gets here in time. I love this hobby!!!

Updated equipment list & specs

LCR's
3 x JBL 4670D's Bi-Amped with 6 QSC RMX 2450 amps bridged to 4 ohms to yield 2400 watts each (obviously 2 amps per speaker)

Front subs
2 x JBL 4642A Amped with 2 QSC RMX 5050 amps bridged to 4 ohms to yield 5000 watts for each sub

Surrounds
4 x JBL 8340A Amped with 2 QSC RMX 2450 amps stereo at 8 ohms to yield 500 watts per channel

IB sub system (manifolds are made to hold 6 drivers each... I have the 4 extra holes plugged at this time. It will however allow expandability for up to 12 18" drivers)
8 x FI CarAudio 18" Q18 drivers Amped with 2 QSC RMX 5050 amps bridged to 4 ohms to yield 5000 watts each (The Q18 drives are custom wired for IB sub system use and have an insane Xmax of 27mm) The 2 QSC RMX 5050 amps will be replacing EP2500 amps...

equipment list (the ones I'm NOT in the process of replacing ASAP)

projector JVC DLA-RS1 (I LOVE THIS PJ!!!)
Onkyo TX-NR905 (on order... I'm waiting)
HD DVD Toshiba HD-AX2
Blu ray Sony PS3
Lumagen RadianceXD (on order... I'm waiting)

After room modifications are complete...
SMX 160" AT screen with CIH masking system

Mark Seaton

06-14-07, 03:37 PM

Hi Dirty,

That's certainly a system that will part your hair! :eek:

While I understand your urge for high power, especially for the front LCR, have you considered going with some better/bigger 2ch amps instead of pairs of bridged lesser amps? With this small a room and >100dB sensitivity from the horns, noise floor could be a serious issue. I suspect this would be easier to deal with using a non-bridged amplifier. The other noise source and issue you will have to deal with will be in the DriveRack 260. These are nice units, but designed for pro use with higher average input levels. You are obviously determined to have some awesome dynamic capability. I'm just posting to make sure you give these smaller details some due attention.

Finally, be sure to pick up some measurement equipment and at minimum get Room EQ Wizard going so you can tame that monster of a system into sounding its best!

KenWH

06-14-07, 03:58 PM

Unfortunately over rated specs are common even in the "better" brand amps like QSC. :( It can even vary within a brand...from model line to model line.

I run several different models of QSC's and they all have been good amps. I bought all but one used off of EBAY and they always seem to deliver a good sound. My favorite QSC model right now is the older EX line. I run a pair of EX1600's on my main l/r and they are cool(literally) as the fans don't activate till the amps actually get hot. With the high sensitivity(100db+) of the JBL's the EX's fans don't even come on during most movies. I wish all my amps were like this.

In addition to the two EX1600's I run a plx1602 on my center, a plx2402 on my 4642sub, a MX 2000a on my 4688 sub and two USA 900's on my surrounds. I have two dedicated 20amp circuits in my equipment closet and have yet to trip a breaker. :cool:

The RMX line is QSC's old school model line as they use large traditional transformers(as opposed to lightweight fancy switching ones first seen the power light series) so just be sure to have plenty of AC power going into the amp rack. You might want to talk with your electrician about arranging the power distribution in such a way minimize ground loop issues as much as possible before he does the rough in. A dedicated breaker box even wouldn't be out of the question on an audio project as large as yours also.

One more thing your going to want to get is a few power sequencer/conditioners to startup/shutdown all those amps. I run two 20amp Furman PS-PRO II's (http://www.furmansound.com/product.php?id=PS-PRO_II) and they work very well for me.

Keep us updated on the progress.

-Ken

KenWH

06-14-07, 04:15 PM

dirtyharriett

06-14-07, 05:35 PM

Nicole,

Mark certainly knows his stuff. I didn't realize till after reading Marks post that your planning on running two amps on each for your front mains. :eek: With the high sensitivity of the JBL's you really don't need that much power.

I use seven amps for my entire system...I run one large amp on each of my front l/c/r mains. My QSC's(and most good pro-amps) are dual mono designs which allows me to run the lowpass out of my crossovers to channel one and the highs from the crossover to channel 2 with no crosstalk and no worry about keeping the ohm loads the same on both channels.

If you have x amount of dollars alotted for amps...I'd suggest considering what Mark said about getting fewer higher quality amps. Though the rmx line is good...it is QSC's entry level amp line.

Ken, I was told to Bi-amp the LCR's by Bill Matthews at Tri-State. The reason I wanted to go with the QSC RMX series is two fold. First they are the most common to find used or refurbished and secondly years ago when I tried to go to the digital amps for weight purposes in my PA system I didn't think they performed nearly as well as my old school QSC's. Times my have changed... it just seems I can get the most bang for my buck going the RMX route. I couldn't even find a place that sells QSC's new cinema amps. Finding them used or refurbished would probably be next to impossible. I'm sure I would end up spending almost 2-3 times as much as I will buying the used/refurbished RMX's (I have a GREAT local source that is giving me awesome prices). If anyboby knows for sure that the RMX's will sound like crap in this system for gods sake please speak now!!!

Solfan

06-14-07, 05:39 PM

Dirtyharriett, that system will be totally insane!! I'd love to get something like that hooked up someday, but I have to get a place waaaaaaay out in the country with no neighbors.

Lotsa more stuff: :)

When I was starting out with this many years ago, I was pissed at how the room lights would dim on loud passages. :confused:
Now I run the bass amps configured for 240VAC,
[Crown MT-2400 for the subs and a Crown K1 for midbass]. There are also three dedicated 120VAC circuits for the other stuff, including the pipsqueak midrange and highs amps. :)

Regarding those big old midrange horns, I never let them run free-standing without some kind of damping material surrounding the edges. Some of them can sound horrible with their natural resonance adding to the mix.

Don't forget yer blocking caps, especially when you're tuning/experimenting! A pretty good supplier has been Madisound.com.

Lastly, a cheap tone-generator is invaluable with these systems to find buzzes and rattles. Loose cabinets, walls and windows etc. can ruin the sound of an an otherwise clean system. Ebay was filled with $25>$100 models last time I checked.

KenWH

06-14-07, 06:57 PM

Ken, I was told to Bi-amp the LCR's by Bill Matthews at Tri-State. The reason I wanted to go with the QSC RMX series is two fold. First they are the most common to find used or refurbished and secondly years ago when I tried to go to the digital amps for weight purposes in my PA system I didn't think they performed nearly as well as my old school QSC's. Times my have changed... it just seems I can get the most bang for my buck going the RMX route. I couldn't even find a place that sells QSC's new cinema amps. Finding them used or refurbished would probably be next to impossible. I'm sure I would end up spending almost 2-3 times as much as I will buying the used/refurbished RMX's (I have a GREAT local source that is giving me awesome prices). If anyboby knows for sure that the RMX's will sound like crap in this system for gods sake please speak now!!!

I've never talked with Bill other than a friendly hi how are you when I stop in at the shop...I usually deal with Fred at Tri-State. They're all nice folks though. :)

Are you sure what Bill meant was two amps per speaker? Running a single amp with the lows on one channel and the highs on the other is considered bi-amping also. Not bridging would also get a bit cleaner sound out of the amp as distortion levels usually go a bit when you start bridging.

Here's a diagram from Crown/JBL showing a medium sized bi-amped cinema system. http://www.crownaudio.com/images/apps/cinema02.gif
Just keep in mind the mains they show are actually three-ways that use a passive x-over between the mids and the tweets.

Even if you wanted to do two amps per speaker, you can run a much smaller(cheaper) amp for the horns as you will already be attenuating the horns so much anyway to bring them inline with the bass section. The horns just don't need very many watts even during LOUD scenes at reference levels and beyond.

RMX's are nice amps don't get me wrong and lots and lots of people run them. If those are what you can get a good deal on then by all means run them. :) The biggest knock I hear on the RMX line is fan noise(you've got that covered).

I listed my amps in an above post and I have both newer switching and traditional non-switching QSC designs. I've found that the bass is indeed stronger and tighter with my traditional transformer equipped amps like my MX2000a. Not to offend anyone but they just seem to have more balls down low. :D

I do think that the modern QSC switching designs do slightly better on the horns though as they seem a bit cleaner sounding. It's probably not enough of an improvement to warrant paying a large premium in cost over the RMX's though.

Mark Seaton

06-14-07, 07:11 PM

Ken, I was told to Bi-amp the LCR's by Bill Matthews at Tri-State. The reason I wanted to go with the QSC RMX series is two fold. First they are the most common to find used or refurbished and secondly years ago when I tried to go to the digital amps for weight purposes in my PA system I didn't think they performed nearly as well as my old school QSC's. Times my have changed... it just seems I can get the most bang for my buck going the RMX route. I couldn't even find a place that sells QSC's new cinema amps. Finding them used or refurbished would probably be next to impossible. I'm sure I would end up spending almost 2-3 times as much as I will buying the used/refurbished RMX's (I have a GREAT local source that is giving me awesome prices). If anyboby knows for sure that the RMX's will sound like crap in this system for gods sake please speak now!!!

Hi Nicole,

The issue is really a matter of gain structure, which we generally don't have to pay much attention to in consumer systems. In pro systems, it's a bigger issue. driving the DR 260 with a receiver and then into pro amps that drive ~100dB sensitivity speakers sets up some concerns about the noise floor through the system, especially in a small room.

There almost certainly will be some low level, background hiss, but if this is managable or objectionable to you is only something you can determine once you set things up. Adjusting the gains through the system will be the tricky part. Fortunatley with the speakers so efficient, you shouldn't have to boost the Onkyo's signal too much.

On the amplifiers, yes, you want to bi-amp, but you don't need to bridge an amp into each driver. You might want to inquire to QSC as to if the PLX2 or other amps might have a lower noise floor vs. the RMX amps or which RMX amps would be better. Off-the-cuff, I would probably suggest switching the 6 x 2450s to 3 x 4050HD's or 5050's. That's a huge amount of power for those speakers, where really a 2450 or 1850HD would be plenty. The issue with bridging is that you double the noise when you basically put the two channels in series. I'd probably save some money with 3 4050HD's up front and then use 2 more for the surrounds over the 2450s. I suspect at that point your still saving money over the current amps. :rolleyes:

Finally, how are you planning to combine the two 4642A subs with the IB?

dirtyharriett

06-14-07, 08:08 PM

Hi Nicole,

The issue is really a matter of gain structure, which we generally don't have to pay much attention to in consumer systems. In pro systems, it's a bigger issue. driving the DR 260 with a receiver and then into pro amps that drive ~100dB sensitivity speakers sets up some concerns about the noise floor through the system, especially in a small room.

There almost certainly will be some low level, background hiss, but if this is managable or objectionable to you is only something you can determine once you set things up. Adjusting the gains through the system will be the tricky part. Fortunatley with the speakers so efficient, you shouldn't have to boost the Onkyo's signal too much.

On the amplifiers, yes, you want to bi-amp, but you don't need to bridge an amp into each driver. You might want to inquire to QSC as to if the PLX2 or other amps might have a lower noise floor vs. the RMX amps or which RMX amps would be better. Off-the-cuff, I would probably suggest switching the 6 x 2450s to 3 x 4050HD's or 5050's. That's a huge amount of power for those speakers, where really a 2450 or 1850HD would be plenty. The issue with bridging is that you double the noise when you basically put the two channels in series. I'd probably save some money with 3 4050HD's up front and then use 2 more for the surrounds over the 2450s. I suspect at that point your still saving money over the current amps. :rolleyes:

Finally, how are you planning to combine the two 4642A subs with the IB?

I'll try to address the issues in order....

Hiss... if this is a problem... in the past when I had PA systems I was able to use a floor gate to completely eliminate any hiss what-so-ever. Will the same trick work for this set-up or will I need it... I don't know yet.

Ok.. I will switch to 3 RMX 5050's to drive the LCR's and bi-amp with the two channels contained in each amp. That will drop my watts from 2400 to 1800 but you say this is overkill anyway.

As far as the subs go… the JBL specs say the peak power for the 4642A's is 4800 watts. I think I will stick with the RMX 5050's bridged to 5000 watts @ 4 ohms. I could certainly gate those without fear of much detail loss. Practically EVERYBODY I know who has large IB systems is driving them with a bridged amp. I think I will stick with the RMX 5050's bridges to 5000 watts @ 4 ohms for them as well. With both of these systems I can always change later BUT I want to atleast give them a try like this.

Well I guess this simplifies amp buying now... It looks like now I'm only buying RMX 5050's. I'm glad I didn't open the box on the 2450... I'm sure my guy at the pro shop with give me full trade towards a 5050...

Mark, as far as the subs between the LCR's…. I have been told by the IB expert guys that the sound from an IB system sounds different than that of a sealed or ported sub system. I fear I have listened to sealed and ported subs for so long that I will miss some of that sound. That is my reasoning for using the two 4642A subs. As far as making all this stuff sound right. That is what I will be paying some sound guys who have forgotten more about this stuff than I will ever know to figure out. I have a real love/hate relationship with all this equipment. I LOVE watching movies... NOT setting it all up. I BEG and pay other people to do that for me.

dirtyharriett

06-14-07, 08:38 PM

I've never talked with Bill other than a friendly hi how are you when I stop in at the shop...I usually deal with Fred at Tri-State. They're all nice folks though. :)

Are you sure what Bill meant was two amps per speaker? Running a single amp with the lows on one channel and the highs on the other is considered bi-amping also. Not bridging would also get a bit cleaner sound out of the amp as distortion levels usually go a bit when you start bridging.

Here's a diagram from Crown/JBL showing a medium sized bi-amped cinema system. http://www.crownaudio.com/images/apps/cinema02.gif
Just keep in mind the mains they show are actually three-ways that use a passive x-over between the mids and the tweets.

Even if you wanted to do two amps per speaker, you can run a much smaller(cheaper) amp for the horns as you will already be attenuating the horns so much anyway to bring them inline with the bass section. The horns just don't need very many watts even during LOUD scenes at reference levels and beyond.

RMX's are nice amps don't get me wrong and lots and lots of people run them. If those are what you can get a good deal on then by all means run them. :) The biggest knock I hear on the RMX line is fan noise(you've got that covered).

I listed my amps in an above post and I have both newer switching and traditional non-switching QSC designs. I've found that the bass is indeed stronger and tighter with my traditional transformer equipped amps like my MX2000a. Not to offend anyone but they just seem to have more balls down low. :D

I do think that the modern QSC switching designs do slightly better on the horns though as they seem a bit cleaner sounding. It's probably not enough of an improvement to warrant paying a large premium in cost over the RMX's though.

Ken, THANKS for the diagram!!! Wish I had the original link so I could see a larger version. I'm going to ask a really dumb question. How did they power 3 sets of surrounds with one channel. I know it is all the same signal but did they use some kind of distribution box or something like that? Bill did say use two amps BUT we were at the time talking about some older much lower power surplus amps he had... not the much more powerful amps I have been suggesting.

Kwikas

06-15-07, 03:42 AM

Originally posted by KenWH
Here's a diagram from Crown/JBL showing a medium sized bi-amped cinema system.

Ken, that's very much the same system I'm proposing in my HT as you know........still debating on what subs to use (IB or 4642A or 4645C etc).....the room is in the design stage presently and I'm having to consider building codes because one wall will run right along the back boundary of our block and there are height restrictions.

Even if you wanted to do two amps per speaker, you can run a much smaller(cheaper) amp for the horns as you will already be attenuating the horns so much anyway to bring them inline with the bass section. The horns just don't need very many watts even during LOUD scenes at reference levels and beyond.

Yes that's absolutely right. The EV Q66's that I'm going to run will be plenty for the LF section and way too much for the tops........so, some care is needed.

By the way, did you buy the BBE 4/8? Have you installed it?

Originally posted by DH
Ken, THANKS for the diagram!!! Wish I had the original link so I could see a larger version.

DH, try here.....http://www.crownaudio.com/pdf/139627.pdf

KenWH

06-15-07, 08:43 AM

Ken, THANKS for the diagram!!! Wish I had the original link so I could see a larger version. I'm going to ask a really dumb question. How did they power 3 sets of surrounds with one channel. I know it is all the same signal but did they use some kind of distribution box or something like that? Bill did say use two amps BUT we were at the time talking about some older much lower power surplus amps he had... not the much more powerful amps I have been suggesting.

Kwikas has the link above for the pdf. They run the surrounds using series/parallel connections...no switch box needed. Most proamps are VERY flexible as to what loads they can drive. For instance your 5050's can drive down to a 2ohm load in stereo and that's basically what load you would get driving 3 pairs of the 8ohm 8340's (wired parallel) in stereo.

edit:
Nicole...don't be so quick to trash the IB idea. Yes 8 of those 18's you selected are expensive but they will go much deeper than the 4642's. Every post I read about IB's rave about the sound quality and deep extension. "The Cult" has a good forum dedicated to IB fans and users. You will need to register to access/post there but those guys know IB's.
http://ibsubwoofers.proboards51.com/index.cgi

KenWH

06-15-07, 08:50 AM

dirtyharriett

06-15-07, 11:32 AM

Kwikas has the link above for the pdf. They run the surrounds using series/parallel connections...no switch box needed. Most proamps are VERY flexible as to what loads they can drive. For instance your 5050's can drive down to a 2ohm load in stereo and that's basically what load you would get driving 3 pairs of the 8ohm 8340's (wired parallel) in stereo.

edit:
Nicole...don't be so quick to trash the IB idea. Yes 8 of those 18's you selected are expensive but they will go much deeper than the 4642's. Every post I read about IB's rave about the sound quality and deep extension. "The Cult" has a good forum dedicated to IB fans and users. You will need to register to access/post there but those guys know IB's.
http://ibsubwoofers.proboards51.com/index.cgi

Ken, what would you think of me doing 3 3632's instead of 3 4760D's for the LCR's. They sure look like they would be easier to mount in a wall baffle and they are 3 way instead of 2 way. What are your thoughts on this. Thanks... Nicole

psgcdn

06-15-07, 11:44 AM

Very impressive stuff guys. Must sound incredible.

I use Klipschorns, Klipsch La Scala and Heresy speakers in my HT and the dynamics and clarity are incredible as well, but my hat is off to you!

dirtyharriett

06-15-07, 11:51 AM

"By the way, did you buy the BBE 4/8? Have you installed it?"

I did...installed it a couple nights ago and so far I'm very happy with it. As far as sound quality and certainly build quality goes it's better than the Behringer digital unit I tried.

The only thing that kinda bugged me is that the user interface via the front panel is not as easy to use as the Behringer so I had to use my desktop computer(via serial port) to set it up. But that's not that big of a deal for a fixed install like mine...now that it's set i shouldn't need to mess with it again.

Ken, I'm sorry but here comes yet another dumb question... how do you squeeze a 7.1 system into a 4 channel input with 8 outputs like the BBE 4/8. It seems like nothing has 8 inputs. What do you do??? just buy two 4 input units? Let me phrase it this way... If you could have ANY speaker management system to control the system I am building and money was not a factor... what would you chose (of course money is always a factor but I just want to see if I can afford what the best piece of equipment for the job is). MANY thanks... Nicole

KenWH

06-15-07, 12:02 PM

Ken, what would you think of me doing 3 3632's instead of 3 4760D's for the LCR's. They sure look like they would be easier to mount in a wall baffle and they are 3 way instead of 2 way. What are your thoughts on this. Thanks... Nicole

Kwikas is doing just that and as I've never heard the 3632's I'll differ to him on those. They certainly should be impressive though I really like the big compression drivers on the 4670/5's. ;)

KenWH

06-15-07, 12:22 PM

Ken, I'm sorry but here comes yet another dumb question... how do you squeeze a 7.1 system into a 4 channel input with 8 outputs like the BBE 4/8. It seems like nothing has 8 inputs. What do you do??? just buy two 4 input units? Let me phrase it this way... If you could have ANY speaker management system to control the system I am building and money was not a factor... what would you chose (of course money is always a factor but I just want to see if I can afford what the best piece of equipment for the job is). MANY thanks... Nicole

Not a dumb question at all. I only run my fronts bi-amped. I have passive JBL 3160a 500hz 2-way x-overs on my surrounds.

As to processors...I'm by no means an expert on the new digital speaker controllers but from my limited knowledge and use the BSS unit Kwikas is using and the Ashley Protea line are both nice higher end units. Though I would imagine the DBX 4800 series is probably the best sonic match for the JBL's if $$$ is not object....brace yourself for this price: :eek: http://www.sweetwater.com/store/detail/DriveRack4800/
This unit has all the configurations(time alignment, eq, x-overs,etc) for the JBL's built in. Lol...I think for that price though it ought to at least have a popcorn popper and a soda fountain built in also. :D

-Ken

Mark Seaton

06-15-07, 03:50 PM

The BEST dsp product in my mind right now is the Dolby Lake Processor. If you are just using it for processing/EQ of main channels it comes in 8x8 format. If you want more channels, you could get one configured as a 4 input x 12 output for your front LCR + Sub and then use one of many 4x4 options for the surrounds.

Other 8x8 processors are the BSS London series, the SymNet products, and many other competitors. If you actually wanted it all in one box, you can easily get the 8 input and 12 outputs you want from BiAmp's AudiaFlex platform. Note that all of these are intended for setup via laptop connection which can even be over a network in most cases.

Kwikas

06-15-07, 11:41 PM

Originally posted by DH.
... If you could have ANY speaker management system to control the system I am building and money was not a factor... what would you chose (of course money is always a factor but I just want to see if I can afford what the best piece of equipment for the job is). MANY thanks... Nicole

Originally posted by Mark Seaton
The BEST dsp product in my mind right now is the Dolby Lake Processor.

Nicole, I believe that Mark is spot on here....and if money were no object, I would have gone down the Dolby route. But money is a factor (for me at least) and I ended up looking closely at three choices for my L/C/R front speaker management....all of them were specifically 3 in and 6 out and high quality units. In no particular order these were Ashly, Xilica and Sabine.

As Ken said, the DBX 4800 is also certainly worth consideration but it was a bit too pricey for me. The advantages are that it does have the JBL pro cinema speaker parameters built into it......(Crown DSi amps have the crossovers built into them - at least they do for the 3632 speakers I believe).

I wasn't considering BSS (purely for cost reasons again) but a BSS soundweb 9088 (8x8) became available down here and so I grabbed it. These are very high end units and I have confidence that it will deliver........

Originally posted by KenWH
I only run my fronts bi-amped. I have passive JBL 3160a 500hz 2-way x-overs on my surrounds.

Unless you want all out processing capabilities and that includes full active crossover management etc of your surrounds, you are likely only going to concern yourself with a processor for the front 3 speakers. The surrounds can be left to run using their passive x-overs as Ken has mentioned. For my part, I have no intention of doing any active x-over management with the surrounds. The passive x-overs will be fine but YMMV.

Mark mentioned "that if you want it all in one box............" and that is certainly worth considering. I didn't want to have several units linked together to manage the fronts. I'm sure the dbx 260 Driveracks will be okay if they are daisy chained(you'll need two if you're looking at managing the fronts only) but a one box solution felt like a better way to go for me.

Originally posted by DH
Ken, what would you think of me doing 3 3632's instead of 3 4760D's for the LCR's. They sure look like they would be easier to mount in a wall baffle and they are 3 way instead of 2 way. What are your thoughts on this. Thanks... Nicole
Today 06:50 AM

Nicole, I didn't start out looking at 3632's. They kind of found me. I got some tops at a really good price so I grabbed them. Now I'm starting to get the other parts of the system. The 3632's are used a lot in screening (post production) rooms.

Look here...http://www.jblpro.com/pressroom/august06/pacificsoundwaves.html

These guys use the 3632 tops but not the bottoms. I'll be using the 3632 bottoms which are known as 3639's.

3632 ScreenArrays are also found in smaller to mid sized cinema's....you may well have been in cinema's that use them.

They are available as either triamped or biamped versions. I'm going with the two ways which means one amp per front speaker. One channel for the LF section and the other channel for the MF/HF section. The MF/HF section utilises a passive crossover.

Originally posted by Solfan
Regarding those big old midrange horns, I never let them run free-standing without some kind of damping material surrounding the edges. Some of them can sound horrible with their natural resonance adding to the mix.

In-so-far as a baffle wall is concerned, I've been told it's not really necessary for the 3632 horns.........but Solfan has a point here. I'm going to run these without a baffle wall to start with and see what happens. I can always build one later - after I've got them aimed properly.

Originally posted by DH
Ken, I'm sorry but here comes yet another dumb question...

I came to this forum quite recently because what I am wanting to do isn't exactly straight forward. I asked a lot of questions and I've learnt a lot from many of the people here. The only 'dumb' thing to do is to not ask the questions you should have. It's much better to be informed....it can save you a lot of time and money. :D

By the way, Mysphyt has a great site that's certainly worth looking at.........
http://www.myhometheater.homestead.com/ProSpeakers.html

This is a great hobby. No-one gets hurt except Mr. Wallet..... :eek:

dirtyharriett

06-16-07, 12:52 PM

Well this has been a very long but enlightening week. Further research has shown another possible QSC amp choice but I am waiting to hear back on prices and availability. The other amp is a QSC DCA 3422. It is their flagship amp in the commercial digital cinema series. It doesn't quite have the power of the QSC RMX 5050 but is supposed to have a lower noise floor. The guy at the pro shop placed a call to QSC and they are supposed to be getting back to him with more info. He DID however tell me that even with ALL RMX 5050's as long as we take care of any A/C power issues that a COMPLETELY silent floor was ABSOLUTELY obtainable with the right equipment and tweaking. With this is mind I will probably end up buying 8 QSC RMX 5050's. I won't be able to make a final decision until I hear back with more info and pricing on the DCA 3422's. It really doesn't make a whole lot of sense to me to give up more clean power if a noise free floor can be achieved with the 5050's unless some other unknown benefit can be achieved with the DCA 3422's. I hopefully should know in less than a week. For the time being after I get the LCR's I will probably just purchase another DBX Driverack 260 off of ebay. After much research I have little doubt that the Dolby Lake processor is the ultimate piece to have for the job BUT at around 5K... It will definitely have to come afterwards as an upgrade. I want to get the whole system up and running ASAP and right now something like that would just eat up too much capital. Does anyone know of a current preamp that has HDMI 1.3, will process Dolby TrueHD and DTS master audio and has BALANCED OUTPUTS? I know I don't have to have balanced outputs but it sure would be nice...

dirtyharriett

06-16-07, 05:03 PM

Spezzy

06-17-07, 08:07 PM

Do any of you guys have any experience with the 8330As? I was thinking about going with these Pro Cinema type speakers too for my room, as I want extremely impressive sound quality. My room is small (1375 cu ft however). I was wondering how you would place the 8330As for surrounds in a 7.1 setup. I am going to be having 2 4642As very soon and I figured I might as well change my surrounds since they are not even JBLs. Also, what would be a good matching set of fronts?

Sorry about butting in, but everytime I asked a question about these JBLs or any of the Pro type JBLs I never get any responses.. :(

Kwikas

06-18-07, 03:27 AM

Originally posted by Spezzy
Do any of you guys have any experience with the 8330As? I was thinking about going with these Pro Cinema type speakers too for my room, as I want extremely impressive sound quality. My room is small (1375 cu ft however). I was wondering how you would place the 8330As for surrounds in a 7.1 setup. I am going to be having 2 4642As very soon and I figured I might as well change my surrounds since they are not even JBLs. Also, what would be a good matching set of fronts?

I am looking at either the 8330A's or the 8340A's too. I'm not sure of the sound differences between these though........can others comment? I'd certainly like to know the answer...........the 8340 has higher power handling and higher sensitivity but the 8330A has better coverage

Placement will depend upon your seating position(s) and the availability of a suitable wall space to affix them to. I wouldn't imagine there would be too much more experimenting around placement of these vs consumer surrounds.......

Matching set of fronts?.......that's much harder to determine since surrounds generally don't have to 'match' the L/C/R's. Matching surround drivers with front drivers is not so important for movies. Some people run entirely different makes of surrounds vs their fronts and are quite okay with this.

You could perhaps consider 3 x JBL 3622N's for your fronts or 3 x 4622N's. Just be aware that you do need a certain amount of room volume to enable full extension with pro cinema speakers. The other thing to ensure is that you are able to have enough space between the L/C/R so as to get sufficient channel separation. I have been told by the pro cinema installers down here that I can't really get away with anything less than 1 full metre between my 3632's up front. That equates to a minimum screen width of 4.3 metres in my set up. How much width do you have?

Two 4642A's in your space...? :eek: My room size will be close to 7,500 cubic feet. I'm contemplating only one 2 x 18" cabinet (EV). Each 18" driver powered by each channel from my K2. This is a 2,000 watt cab design and will be more than sufficient.....unless you are like some of the other people in this forum.... :D

Spezzy

06-18-07, 01:50 PM

I am looking at either the 8330A's or the 8340A's too. I'm not sure of the sound differences between these though........can others comment? I'd certainly like to know the answer...........the 8340 has higher power handling and higher sensitivity but the 8330A has better coverage

Placement will depend upon your seating position(s) and the availability of a suitable wall space to affix them to. I wouldn't imagine there would be too much more experimenting around placement of these vs consumer surrounds.......

Matching set of fronts?.......that's much harder to determine since surrounds generally don't have to 'match' the L/C/R's. Matching surround drivers with front drivers is not so important for movies. Some people run entirely different makes of surrounds vs their fronts and are quite okay with this.

You could perhaps consider 3 x JBL 3622N's for your fronts or 3 x 4622N's. Just be aware that you do need a certain amount of room volume to enable full extension with pro cinema speakers. The other thing to ensure is that you are able to have enough space between the L/C/R so as to get sufficient channel separation. I have been told by the pro cinema installers down here that I can't really get away with anything less than 1 full metre between my 3632's up front. That equates to a minimum screen width of 4.3 metres in my set up. How much width do you have?

Two 4642A's in your space...? :eek: My room size will be close to 7,500 cubic feet. I'm contemplating only one 2 x 18" cabinet (EV). Each 18" driver powered by each channel from my K2. This is a 2,000 watt cab design and will be more than sufficient.....unless you are like some of the other people in this forum.... :D

I was initially going the DIY route, but locally I could get 2 of them for $500. Plus they're in perfect condition. I was thinking of using a Linkwitz Transform to bring up the Low-end :)

3662Ns are nice.. So are the other ones. But I think I will stick with my other fronts and center for now :o My room is not going to fit them, my room is about 10ft wide. lol.

These surrounds.. I would put one on each side wall and the other 2 in back correct? I've never used di-poles so I don't know much about placing these. :confused: Right now I'm using monopoles for rears and bipoles for side. I'm hoping these JBL surrounds will improve my surround sound experience :D
I'm thinking the 8330As would be a much better sounding speaker since it is a 3-way, should give some better sounding vocals. Should these surrounds be mounted up high?

Kwikas

06-19-07, 11:37 PM

Originally posted by Digital2004
As far as subs a concerned, it's always better to ADD subs than sending 1500w to just one or two ! power compression at some time appears. Besides you'd only gain 2-3db max by doubling the power (from 700 to 1400W). Much better adding subs. Besides adding subs wil reduce room modes and increase bass response a the seating positions as nulls decrese and peaks flatten (of course also influenced by sub placement, bass treatement and EQ).
By heaving subs on the left and right corners, and the mains on top (the 15" equipped mains) you further reduce room modes in the vertical plan.
Adding subs between the left and right subs also reduce room modes. You want to create an "infinite" line of array of bass sources horizontally. If budget allows, that would mean for instance if the room is 4meters wide (and so would the screen like in theaters ), a cinemascope screen), you would need for instance about 6 4645C subs (then the mains should be above,

Okay, since I'm at the planning/drawing phase for the room I'm keen to know a little more about sub placement.........

The screen will be 750mm off the floor and I can build a large wall cavity (stage) to run all the way along the front wall behind the screen to sit my 3632's onto. The screen will fit in front of the stage...it will be around 4.5 metres long.

What are you pro gear guys doing as regards sub placement? I know some of you have them along the side walls (like KenWH) but what about putting the subs between the L/C/R speakers behind the screen? Is anyone doing this?

I could also consider putting the sub(s) into the front corner(s) of the room below the screen and recess them back in underneath. I believe the corners are a better place for subs than under the screen and directly in front........yes?

People have pointed out that you need to experiment with placement and I accept that. My problem however, is that this room is going to double as a childrens play room so I don't want the speakers out in the room. Period. The subs need to be below the screen (recessed under the stage floor at the sides or front) or behind the screen.

Sorry purists but I don't get much choice on this....... there has to be allowances for the WAF. As it is, I'm getting away with a lot of spend here ;)

I take Digitals point about there being a better case to have multiple subs rather than just one or two 18" gunners fed with bridged power.

I have the opportunity to buy 2 sub cabinets each one with 2 x 18" drivers. Does this change the rules any? How would you consider placement of these - particularly given that you can't experiment that much, except between the two positions I've mentioned..

Finally, what are your thoughts about the number of sub cabinets...? Is one 2 x 18" enough or should I look at getting two 2 x 18"? The room will be about 7,500 cubic feet....

Thanks as always

KenWH

06-20-07, 09:04 AM

Okay, since I'm at the planning/drawing phase for the room I'm keen to know a little more about sub placement.........

The screen will be 750mm off the floor and I can build a large wall cavity (stage) to run all the way along the front wall behind the screen to sit my 3632's onto. The screen will fit in front of the stage...it will be around 4.5 metres long.

What are you pro gear guys doing as regards sub placement? I know some of you have them along the side walls (like KenWH) but what about putting the subs between the L/C/R speakers behind the screen? Is anyone doing this?

I could also consider putting the sub(s) into the front corner(s) of the room below the screen and recess them back in underneath. I believe the corners are a better place for subs than under the screen and directly in front........yes?

People have pointed out that you need to experiment with placement and I accept that. My problem however, is that this room is going to double as a childrens play room so I don't want the speakers out in the room. Period. The subs need to be below the screen (recessed under the stage floor at the sides or front) or behind the screen.

Sorry purists but I don't get much choice on this....... there has to be allowances for the WAF. As it is, I'm getting away with a lot of spend here ;)

I take Digitals point about there being a better case to have multiple subs rather than just one or two 18" gunners fed with bridged power.

I have the opportunity to buy 2 sub cabinets each one with 2 x 18" drivers. Does this change the rules any? How would you consider placement of these - particularly given that you can't experiment that much, except between the two positions I've mentioned..

Finally, what are your thoughts about the number of sub cabinets...? Is one 2 x 18" enough or should I look at getting two 2 x 18"? The room will be about 7,500 cubic feet....

Thanks as always

Hi Kiwkas,

Sub placement is so room dependent experimenting is best but since your limited to the front portion of your room the following should apply:

Corner placement will likely get you the highest spl's and possible deepest bass response but may be boomy sounding as the corners boost certain frequencies more than others. Away from the corners the flatter the response...as a rule. Of course you can put them in corners and then use eq's to flatten the peaks.

When using two subs....to get the maximum coupling effect between them they need to be as close to each other as possible. If they are right next to each other you should get at least a 3db sensitivity increase as essentially they become one large subwoofer. If they are placed away from each other...say one in each front corner you should still see a gain with the second sub but it will only be about a db or so...but the "coverage" through out the room should be more even.

Imo...with your room requirements I'd probably try to put one in each front corner and eq them if needed.

Kwikas

06-21-07, 09:06 AM

KenWH

06-21-07, 09:31 AM

Thanks for the advice Ken.

I was thinking to go the IB route but it's going to be too difficult given the room configuration so I've settled on 18" ported designs....hence my placement question.

I've still got quite some way to go yet but the planning stage is fun none-the-less..... :)

...as the gear buying. :D

Are you running 2 single 18" JBL's for your subs or more than this?

Cheers

I'm running two dual 18's...total overkill but I love bass. :p

On one side of the room I'm running a 4642a(upgraded it with 2242 woofers) and on the other side I'm running an older 4688(using the 2241 woofers that originally came in my 4642a) that i bought used from my theater supply house. Since the 4688 is an older design many are not familiar with it. It's more of a bandpass style design rather than ported.
http://www.jblpro.com/pub/obsolete/4688.pdf

It's a pretty impressive sub and I got it for a pretty cheap price. Though I'd rather have another 4642a as it's more efficient, plays a bit deeper, and looks a little better imo. :D

Kwikas

06-22-07, 04:50 AM

Originally posted by KenWH
I'm running two dual 18's...total overkill but I love bass.

You'd need to....... :D :D

I'm looking closely at buying 2 dual 18" EV cabs right now.........not sure how I'll go on getting these but we'll see. The seller claims 20hz - 400 hz and if that's correct then they should do the business :eek:

I'd love the JBL 2242 drivers like you have but the pro gear down here is quite scarce and it's best to grab it when the opportunity comes up. Since we're talking about subs here, I'm not too concerned just so long as the brand is reputable. However, I will certainly be finishing the rest of my speaker set up with JBL's regardless of what subs I end up getting.

The BSS 9088 is 8 in 8 out and I've already taken up 6 outs for the fronts which leaves me with 2 more outs. I thought I might use these for the two subs so as to have some independent bass management.

Do you have any comments around the 8340's vs the 8330's for surrounds? I would think that the 8340 is the next step on but I'm not sure.....

Cheers

KenWH

06-22-07, 09:12 AM

Certainly nothing wrong with EV gear. Do you know which model EV sub your looking at?

Looking at the EV subs on THX's cinema equipment list I would guess they would all perform well with the jbl full-ranges...with the most notable difference in subs being output between single and dual woofer units.
http://www.thx.com/products/professional/pdf/ApprovedEquipList.pdf

Most are spec'd to have around 10db or slightly more drop off at 20hz so don't expect a ton of infrasonic output. Really you won't get great below 20hz bass with any of the large cinema subs...regardless of brand. I run a high pass filter at around 18-19hz on both of my JBL subs.

Using the extra channels on the BSS for the subs should work fine.

I can't really say much on the surrounds...I've never used them. Though before building my diy rears...I was all but set on getting a pair of 8340's as I liked that it was more efficient and that it had the horn hf section. I have yet to hear dome tweeter equipped speakers blend with horn tweeter equipped speakers properly. They 8330's may work fine...but I like horns.:)

Your in Australia...correct? KRIX is based/built there and they happen to have an impressive looking pro cinema line. Have you considered their subs or any of their other cinema gear?

-Ken

http://www.krix.com.au/

Kwikas

06-22-07, 07:04 PM

Ken,

Yeah, I'm in Melbourne...

I don't know what the drivers are in the EV cabs. The guy wont pull them out but he says they are definitely EV and both of the dual cabs he's selling have come out of an install. They seem to be in very good condition but they aren't the TL880's. The TL's use the EX 180B drivers I believe.

I do know that some time ago the EV importer here commissioned a cabinet builder to custom make dual and single cabs around the EV 18" driver specs. These were very popular and found their way into a lot of cinema's and clubs and I think these are two such units..... I don't doubt his 20hz - 400 hz claim...... :cool:

I found a website a while back (didn't bookmark it so now gone :mad: ) which showed a very expensive private home theatre in the USA. The designers/installers had selected JBL fronts and surrounds but gone with EV TL880 dual cabs for subs. I was a little surprised on the sub choice given that the JBL 2242 drivers are newer designs than the EV offering. From what I hear the 2242's like you have are an incredible driver.

Still, I think any of the pro speaker makers like JBL, EV, EAW Klipsch etc are more similar than different when it comes to their commercial offerings....and for nearly all of these commercial subs 20hz seems to be about the bottom limit as you point out.......for me that's plenty low enough and 4 of these 18" drivers should provide more than enough shake :eek:

I'll let you know if I'm successful with the purchase.....

Yeah, I've spoken with Krix. They make really nice gear and I think their drivers are Beyma....http://www.beyma.com/

They are not to be confused with the Chinese Biema. :D and if you ask me, those names are a little too close........

I wouldn't object to owning any of the Krix pro stuff but again it just depends what comes up for sale on the second hand market. I've yet to see one single piece of Krix gear surface for sale down here. It's difficult enough to find JBL or EV pro gear and when it does, you've got to grab it......or you'll miss it and be waiting another several (long) months.

I'm extremely envious of the ease at which you guys in the USA can get this stuff...and your prices are rediculously cheap.. :mad:

Thanks for the advice on the 8340's vs 8330's..........I'll go with the 8340's

Cheers

Kwikas

06-23-07, 10:21 PM

I'll let you know if I'm successful with the purchase.....

Got 'em........ :cool:

KenWH

06-24-07, 12:25 PM

Kwikas,

More than likely your EV's have this woofer:
http://www.partsexpress.com/pe/pshowdetl.cfm?&Partnumber=294-565 :D

-Ken

KenWH

06-24-07, 12:59 PM

Kwikas,

Here's EV's page on the tl880d. It uses a pair of the woofers I linked above. Is this the subs you got? I know earlier you weren't sure which units you'd be getting.

If they don't have an id tag on the back look for the dual small rectangular ports. I don't recall seeing that port configuration on any other brand of large cinema sub.

You may also be able to use a small mirror and a flashlight to see the back of the woofers to confirm the model #'s of woofers. But more than likely it will be the EVX-180's. EV makes another 18" woofer in the MT driver line but in cinema applications I believe the EVX driver line is what is used.

EDIT:

Sorry just re-read your above post. So your sure they're not 880's. So at this point we're just trying to id the drivers. Ok...the obvious approach :) :if you can see inside the box(through the ports) the magnets should have an id sticker. Also from looking at pictures of each of the 18's EV makes...the EVX cone is a very dark charcoal gray...almost black where the MT 18 is a good bit lighter gray.
Also it appears the EVX line uses a one piece rubber gasket/trim piece around the lip of the frame and the MT line uses paper/foam gasket with relief cuts around the screw holes.

Check here for pics of each:http://www.electrovoice.com/products/223.html

Kwikas

06-25-07, 12:01 AM

Originally posted by KenWH
Sorry just re-read your above post. So your sure they're not 880's. So at this point we're just trying to id the drivers. Ok...the obvious approach :if you can see inside the box(through the ports) the magnets should have an id sticker. Also from looking at pictures of each of the 18's EV makes...the EVX cone is a very dark charcoal gray...almost black where the MT 18 is a good bit lighter gray.
Also it appears the EVX line uses a one piece rubber gasket/trim piece around the lip of the frame and the MT line uses paper/foam gasket with relief cuts around the screw holes.

Thanks for all the links and info Ken. The cabs are located in Sydney so I'm going to have to get them down to Melbourne. I'm arranging for this to happen mid July when I'm next up in Sydney on business. I wont see them before that unfortunately......but I'll let you know once I have ID'd the drivers.

The cabs are definitely not TL880's. I think they are the locally built ones but this doesn't concern me as I've been told that these cabinets were very well built...better built than the EV boxes even....they have 4 round vents in each cab (2 per driver).

I was shocked at the price on the page you linked us to. If they are indeed the EX180B drivers then I've got an incredibly good deal. I think they are more likely to be the 180A though.....we'll see.........

Cheers

MichaelCarey

06-25-07, 12:32 AM

While not exactly marketed as cinema speakers, my Whise Profunder 624 sub is certainly in the same league.
I'm almost scared to let it really go at extreme clockwise end of the dial. The 624 consists of two enclosures, each with a 15" driver. Being a passive system, I drive mine with a Yamaha P2500 amplifier in bridge mode. You can see my 624 in the first link in my sig.
http://www.whise.com.au/reviews.htm
More suited to a recording or post-production studio, I get plenty of deep, clean, powerful bass.

I've always gone for the overkill in subs. Before the Profunder 624, I had a home-build bandpass sub based on a JBL 2242H 18" driver. This also provided me with excellent results, when I bought the Profunder 624, I donated it to a local church for use during their "youth" services where it could really stretch it's legs.

Michael.

Kwikas

06-25-07, 04:17 AM

Originally posted by MichaelCarey
While not exactly marketed as cinema speakers, my Whise Profunder 624 sub is certainly in the same league.

I think we can certainly call this one a pro sub Michael... even if it hasn't found its way into cinema's...;)

I haven't heard of these......are they still being made? I may well have looked around for one if I'd known sooner.......it sounds like a beast :eek:

Originally posted by KenWH
So at this point we're just trying to id the drivers.

Ken, I've now been told that the dual 18" EV cabs that were made here locally were called the EV X218. This was a name given to them by the seller/distributor. They are not found on the EV website (for obvious reasons) and they use two EV X180A drivers. The 'B' driver is the later version but apparently there is very little difference between these drivers and by that I mean it's not worth swapping them out.

Have you guys seen this?......http://www.harman.com/wp/pdf/multsubs.pdf

I makes for some interesting reading.

Originally posted by KenWH
I have yet to hear dome tweeter equipped speakers blend with horn tweeter equipped speakers properly. They 8330's may work fine...but I like horns.

I'm kind of wrestling with the surrounds right now. The JBL 8340's are a logical choice given my fronts but I've now had a great offer on some EV ZX1's and they would also be quite suitable....... probably.........:confused:
These are also horn loaded BUT they have never been used in commercial cinema's - at least not to my knowledge. Does this make them unfit for use in home cinema though. Probably not.

I notice from comparing the specs however that the JBL 8340A gives slightly better coverage at 100 degrees horizontal and 60 degrees vertical. Whereas the ZX1's are 90 degrees horizontal and 50 degrees vertical.

There is an EV ZX1I (installation) model that provides 100 degrees of coverage both ways.....that's got to be a good thing. I might do some further investigation on these too I think.......

MichaelCarey

06-25-07, 05:41 PM

I think we can certainly call this one a pro sub Michael... even if it hasn't found its way into cinema's...;)

I haven't heard of these......are they still being made? I may well have looked around for one if I'd known sooner.......it sounds like a beast :eek:

I'm not sure on where Whise is at the moment, I bought mine in 2001 (I think).
I thought they had been bought out by Whatmough (another Australian speaker company), their Impulse and Impact subs are based on PAM technology developed by Whise. When I go to the Whise web page now, there is a new address and a head company I have never heard of before. The Profunder 624 had a big brother, the Profunder 616... a MONSTER of a passive sub more suited to much larger venues than my HT!
If you do a Google search on PAM and Profunder 616 you can find some interesting reading. The 624 is also mentioned on Tom Holman's web page
www.tmhlabs.com

Michael.

KenWH

06-25-07, 06:32 PM

Speaking of Tom Holman(as in the Tom Holman eXperiment aka:THX)... I recently had an opportunity to buy a large old Kintek powered sub. At the time I'd never heard of Kintek but after doing a bit of research it turns out that George Lucas ran the same Kintek's back in the 80's for their main screening room at Skywalker Ranch. It must have been pretty good subs.

If I had known that it was such good sub I would have bought it in a second.

edit:
corrected spelling for Kintek.

Kwikas

06-25-07, 11:48 PM

If I had known that it was such good sub I would have bought it in a second.

...and had three subs.... :eek: :eek: :D

Digital2004

06-26-07, 12:51 AM

wow, my thread has gone bazooka :)
Dirty: what room size ????????? dont overkill. dont bridge either, absolutely no need for home theater use. you won't have more than 50seats, 12x7meters HTroom are you ??
bridgin raises distorsion 3x btw

go with the QSC DCA amps
use a quality preamp (sunfire, or a receiver with EQ and a Genelec RCA XLR converter)

acoustics !!!!! you must make:
a front thx wall or even baffle the speakers
put resonators in the room corners (big stuff)
make a stadium with at least 3 rows if you want such a big speakers system

here is one great system:
3 3677 or 3678 on top of 3 4648 enclosures driven by one DCA 1622 (plenty enough) with
XC3 crossover. signal from sce: crossover at 40hz (below 40hz going to the 4645C subs)
biamp the combination of 3677 or 78+ 4648 with one DCA 1622
crossover of biamp: 500hz

4 4645C subs (LFE + <40hz from other channels) with 2 DCA 3422 feeding them

6 8450A surrounds with 1xQSC DCA 1824 (4channels amp)

SMS1 velodyne equalizing the subs and subsonic filter on at 20hz 12db/octave

screen: microperforated 1.1gain (not painted !) curved scope 4meters screen (beyond that the RS1 can"t, you'd need 2000ansi lumens)
3 or 4 rows of 5 cinema seats

dont make things too complex and avoid overcrowding the system from amps to speakers to preserve maximum of dynamics. the DCA line also has several controllers via PC.

enjoy :)

note that QSC has an excellent line of cinema speakers, very very well designed and built like tanks. i would seriously consider them too, notjust their amps

KenWH

06-26-07, 09:17 AM

...and had three subs.... :eek: :eek: :D

Nahhh...couldn't fit another big sub in my room...even if I wanted to. I would have got the Kintek instead of the 4688. The JBL was much cheaper and at the time I had never heard of Kentec so I passed on it for the JBL. By the time I figured out what the Kintek was it had been sold. :(

Here's an article (http://www.rawsound.com/articles/THX2/index.html) detailing the early day's at the Skywalker Ranch. Under "SUBWOOFERS" they talk briefly about the Kintek's.

Kwikas

07-02-07, 09:42 AM

Originally posted by digital2004
6 8450A surrounds with 1xQSC DCA 1824 (4channels amp)

Hey digital, I looked for these but couldn't find them anywhere. Do you mean JBL 8340A's? I'm looking at these or the EV FRi-2082 for surrounds. I like the 100 deg x 100 deg coverage pattern offered by the EV's.........you can check them out here
http://www.electrovoice.com/productfamilies/41.html

Kwik

Curt Palme

07-02-07, 11:12 AM

I just hooked up three EAW JP260 speakers for LCR and added a Tannoy CPA 12.3 sub cabinet.

http://www.eaw.com/info/EAW/Loudspeaker_Product_Info/Legacy_Loudspeakers/JF_Series/JF260e/JF260e.pdf

http://translate.google.com/translate?hl=en&sl=zh-TW&u=http://market.myav.com.tw/shop/detail.php%3Fwwwid%3Dcd9ffdb73dbaebccd2acc9d2dbbf5c1d%26id%3 Dda327b994ae14c97fd7ae29c1ec120e5&sa=X&oi=translate&resnum=1&ct=result&prev=/search%3Fq%3Dtannoy%2Bcpa12.3%26hl%3Den%26rls%3DGGLR,GGLR:20 06-14,GGLR:en

Next up- room treatment, more AC circuits and a tensioned screen, eqs and a room sweep to get rid of rattles.

Kwikas

08-21-07, 06:44 AM

Originally posted by Curt
I just hooked up three EAW JP260 speakers for LCR and added a Tannoy CPA 12.3 sub cabinet.

Curt, how did you go with these? Are you happy with the results?

The plans are now being drawn up by the architect for a stand alone Rumpus room / Cinema at the back of our yard. It will be concrete block construction but it's going to be compromised somewhat by the windows. However, the WAF came into play here and with the large spend on the room and equipment, I wasn't going to get it all my own way.......:(

Okay, I need some help guys........I've searched and searched but can not find plans for a JBL 4507A LF enlosure OR a JBL 4509 LF enclosure. Does JBL ever publish detailed plans for their enclosures? Has anybody got data or plans on either of these cabinets that they can share?

Thanks

djshtnut

08-21-07, 07:41 AM

KenWH,

Awesome speakers! I would love to have those!

coldmachine

08-21-07, 09:22 AM

Is no-one else out there using large Genelecs?

Im using a 7.1 324a and 324c based system and it has to be the best SQ I've ever heard. SPLs are astounding with stellar fidelity, trully mastering quality. Each speaker is active tri-amped. One of the main benefits of a system like this is the installation and calibration by people with decades of studio monitoring expertise. I've yet to see thier equal.

KenWH

08-21-07, 09:47 AM

Originally posted by Curt

Curt, how did you go with these? Are you happy with the results?

The plans are now being drawn up by the architect for a stand alone Rumpus room / Cinema at the back of our yard. It will be concrete block construction but it's going to be compromised somewhat by the windows. However, the WAF came into play here and with the large spend on the room and equipment, I wasn't going to get it all my own way.......:(

Okay, I need some help guys........I've searched and searched but can not find plans for a JBL 4507A LF enlosure OR a JBL 4509 LF enclosure. Does JBL ever publish detailed plans for their enclosures? Has anybody got data or plans on either of these cabinets that they can share?

Thanks

I've never seen detailed plans for JBL's "utility" cabs on the net. Looking at my empty 4508 the construction is pretty straight forward though.

You've probably already found these but here's a 3-way that uses the 4507a for lf and has basic dimensions for it: http://www.jblpro.com/pages/pub/cinema/5671.pdf

Here's a bit more info on the non "a" 4507:
http://www.jblpro.com/pub/obsolete/Low_Frequency_Enclosures1.pdf

Here's a 3-way that uses the 4509 and lists the lf enclosure dimensions also.

You might also look around and/or ask for details here: http://www.audioheritage.org/vbulletin/

Sorry I couldn't be more help.

Ken

Curt Palme

08-21-07, 10:30 AM

Originally posted by Curt

Curt, how did you go with these? Are you happy with the results?

Thanks

Yes, they sound much better than the Community cabinets that I had in there. Mind you, the center channel on the Communities weren't matched to the L and R, so that's a big difference. The whole room needs massive treatment though, that's the big problem now. Sales have been slow over the summer, and to add insult to injury, the corporate sales I had are slow paying, so I've done zero with the room in the last couple of months. Haven't even watched a movie in it.

Just got an HD DVD player and a Lumagen and DVI card for the projector, so that's the next move. Then as a bonus, the new g/f seems to know more about construction than I do, so he says she'll help me pull in a wall to hide the speakers and to mount the fixed screen. How cool is THAT? :p

Kwikas

08-21-07, 09:29 PM

Originally posted by coldmachine
Im using a 7.1 324a and 324c based system and it has to be the best SQ I've ever heard. SPLs are astounding with stellar fidelity, trully mastering quality. Each speaker is active tri-amped. One of the main benefits of a system like this is the installation and calibration by people with decades of studio monitoring expertise. I've yet to see thier equal.

Damn right cm. I'm just part way through this process (gear purchase and room planning) and it's much more of a 'journey' than the installation of regular plug and play systems. To wring the best out of pro gear, there is a lot of effort and expertise required. You've obviously sought out the best advice and got the right people involved. This is something I'm going to have to do as well. Fortunately while going through this, I've been able to make contact with people who know their stuff around installing and calibrating commercial JBL speaker systems..........and they will be called upon!!!..:D

Originally posted by Curt
Just got an HD DVD player and a Lumagen and DVI card for the projector, so that's the next move. Then as a bonus, the new g/f seems to know more about construction than I do, so he says she'll help me pull in a wall to hide the speakers and to mount the fixed screen. How cool is THAT?

Sometimes you just luck out!..:D
I'm keen to know more about your full(?) baffle wall build Curt. Some people say it's necessary while others are less concerned about it. All of the photo's I've seen around JBL 3632 ScreenArray installations show them mounted in a full baffle wall. It's going to be extra work to do but I'll do it if the concensus is that it will give a real and measurable SQ improvement. I was thinking to start without one first though........

Origianlly posted by KenWH
I've never seen detailed plans for JBL's "utility" cabs on the net. Looking at my empty 4508 the construction is pretty straight forward though.

Thanks Ken. I will go the Audioheritage site and ask.......I've been to the other sites you provided already. It's good to know I've not missed anything around the JBL cabinets. I haven't shipped the LF cabs for the 3632 out of the USA as yet and I'm now starting to wonder about whether I should just build them here instead. Decisions.....decisions........:confused:

I was more or less settling on the 4509 LF enclosure but then I saw that JBL have recently launched the 3631 ScreenArray which uses the same 3632 MF/HF top but a 4507A LF cab. I could probably build either LF cab.........interestingly, I can buy 2 M115-8A 15" drivers for the 4509 LF cab for about the same price as 1 2226H driver for the 4507A cab.

I think the 3631 SceeenArray was born out of the work JBL did with the Pacific Soundwaves screening rooms in 2006.

Sonically, JBL are claiming that the 3631 ScreenArray with the 4507A LF cab is slightly better than the 3632 ScreenArray with the 4509 LF cab. It's probably academic for room though......

coldmachine

08-22-07, 03:52 AM

Originally posted by coldmachine

Damn right cm. I'm just part way through this process (gear purchase and room planning) and it's much more of a 'journey' than the installation of regular plug and play systems. To wring the best out of pro gear, there is a lot of effort and expertise required. You've obviously sought out the best advice and got the right people involved. This is something I'm going to have to do as well. Fortunately while going through this, I've been able to make contact with people who know their stuff around installing and calibrating commercial JBL speaker systems..........and they will be called upon!!!..:D

If its of interest to you, the only other company that was able to even come close to Genelec in terms of pure performance and quality was Dynaudio.

What budget are you working with for your sound system ?

Kwikas

08-22-07, 06:47 AM

Originally posted by coldmachine
If its of interest to you, the only other company that was able to even come close to Genelec in terms of pure performance and quality was Dynaudio.

What budget are you working with for your sound system ?

Thanks for the thoughts and advice here cm. I've got a large amount of money already invested in the JBL's (3632 MF/HF sections) and EV subs (4 x 18") so a move to other speakers - at this point at least, isn't an option for me....or the wife..:D

Kwikas

08-22-07, 08:23 AM

Originally posted by KenWH
I've never seen detailed plans for JBL's "utility" cabs on the net. Looking at my empty 4508 the construction is pretty straight forward though.
Ken, I've seen elsewhere some comments around JBL utility cabinets that suggested they were okay for quality and okay for construction. They aren't fantastic though and a custom cabinet maker could do a lot better.......for a price. Would you say this is right?

Fundamentally, it seems to me that an unloaded JBL utility cabinet is cheap......but they do the job. And, given that they are hidden away in commercial installs, the importance of performance outweights asthetics anyway.

I have looked at shipping the JBL cabinets out of the USA - loaded or unloaded, because they are cheap over your side BUT the freighting costs to Australia (at mates rates too by the way) is pretty darn hefty. That's because the freight companies work on a formula of weight vs volume and charge for whichever is the greater of the two.

So, I've been thinking about building the LF cabs myself..........either the 4509 or the 4507A. I haven't given up the idea of buying in the USA and shipping out to Australia but building 3 LF cabs might be the best option...........

coldmachine

08-22-07, 08:47 AM

Originally posted by coldmachine

Thanks for the thoughts and advice here cm. I've got a large amount of money already invested in the JBL's (3632 MF/HF sections) and EV subs (4 x 18") so a move to other speakers - at this point at least, isn't an option for me....or the wife..:D

No probs. Just checked out those JBL units. The Genelecs wouldnt really be a similar product, forget my suggestion.

Good luck with your project.

KenWH

08-22-07, 02:26 PM

Originally posted by KenWH

Ken, I've seen elsewhere some comments around JBL utility cabinets that suggested they were okay for quality and okay for construction. They aren't fantastic though and a custom cabinet maker could do a lot better.......for a price. Would you say this is right?

I would agree totally here. Other than having dado'd joints for the front and rear panels there is really nothing difficult or tricky about their contstruction. A few of my cabs(remember I bought them all used) failed the knuckle test and rattled so I went ahead and pulled the woofers from all the cabs and applied new addesive/sealant along with some extra cleating in the weak spots.

Fundamentally, it seems to me that an unloaded JBL utility cabinet is cheap......but they do the job. And, given that they are hidden away in commercial installs, the importance of performance outweights asthetics anyway.

My thought exactly...the big black boxes aren't going to win any beauty contests. I personally like the industrial look so other than a bit of flat black touch up paint I'm running them just as they were when they were pulled from the cinema.

I have looked at shipping the JBL cabinets out of the USA - loaded or unloaded, because they are cheap over your side BUT the freighting costs to Australia (at mates rates too by the way) is pretty darn hefty. That's because the freight companies work on a formula of weight vs volume and charge for whichever is the greater of the two.

So, I've been thinking about building the LF cabs myself..........either the 4509 or the 4507A. I haven't given up the idea of buying in the USA and shipping out to Australia but building 3 LF cabs might be the best option.

Yah int'l shipping is a nightmare for such large items...I would certainly look into your idea of doing "custom" boxes either through a cabinent maker or if your handy with power tools making them yourself. I don't know if you looking to adhere directly with JBL's factory tunings for the cabs but building your own would allow you to "tune" them exactly how you wish.

Again the folks over at the heritage site would be the brains to tap on different box volumes and tunings. When I decided to build my own rear centers to match my 4670's & 75's they were a big help in getting me a usable design and they turned out great.

Take care,
Ken

Kwikas

08-29-07, 07:31 AM

Originally posted by KenWH
Again the folks over at the heritage site would be the brains to tap on different box volumes and tunings. When I decided to build my own rear centers to match my 4670's & 75's they were a big help in getting me a usable design and they turned out great.

Good advice thanks, and I've started the discussion over there.........I'm going to go with making up three 4507A's and I'll tune them to 40hz.

It looks as though the 4507A's are simply 4507's but the drivers have been moved to the centre.

I can't see these being too difficult to make and in fact I'll probably end up with a better built cab....so it's 3631 ScreenArray's now rather than 3632's.

Ken, what type of speaker cable connects do the LF sections on your 4's have? I've never been able to eyeball what JBL use........and how are these wired through to the drivers in the cab i.e. how have they ensured there are no holes & it's air tight?

I see some EV Fri speakers on e-bay. Nice - and probably my first choice for surounds but at USD400/pr and out of Canada I'll have to pass......:(

By the way, we got our first plan draft for the HT / Rumpus room back from the architect today so it's starting to move along...

Kwikas

08-29-07, 08:15 AM

Originally posted by KenWH
I would agree totally here. Other than having dado'd joints for the front and rear panels there is really nothing difficult or tricky about their contstruction. A few of my cabs(remember I bought them all used) failed the knuckle test and rattled so I went ahead and pulled the woofers from all the cabs and applied new addesive/sealant along with some extra cleating in the weak spots.

I think the two top and two bottom edges are mitred (45 degrees) joints...and the front baffle and rear are dado's...yes? The baffles are set in about 1 cm from the front edges of the cab but the back is flush.....

I was going to do dado's on all joints....doing a 45 degree mitre is pretty difficult.

What bracing did you see inside your cabs? Was there much?

KenWH

08-29-07, 05:13 PM

Originally posted by KenWH

I think the two top and two bottom edges are mitred (45 degrees) joints...and the front baffle and rear are dado's...yes? The baffles are set in about 1 cm from the front edges of the cab but the back is flush.....

I was going to do dado's on all joints....doing a 45 degree mitre is pretty difficult.

What bracing did you see inside your cabs? Was there much?

It looks like the joint where the top and bottom panels meet the side panels are on a 45 with the front and rear baffle dado'd in about 1/4" from the edge all around(front and rear).

bracing:
Hopefully the pics will give you a good idea as to bracing.
Basically there's a pair of 1x4's on the rear baffle running the full length top to bottom. There is also a single full length(top to bottom) 1x4 on each side panel. Finally there's a single short piece of 1x4 mounted between the ports going from the front baffle to the rear.

There's also several small cleats on the long joints to add additional strength.

If you need more pics or have any other questions let me know.

-Ken
edit:
there's also a short 1x4 brace on the top and bottom pieces also.

KenWH

08-29-07, 05:23 PM

As to the wires you can see the stock(thin) JBL wire in one of the pics. JBL uses a "universal" cut out on the rear baffle and depending on what is needed for the application they can swap in different x-overs or binding posts. Mine simply have binding posts which are mounted on 3/4" particle board about 2" larger than the hole in the rear baffle. This piece in mounted(screwed) on the inside of the cab and uses a small gasket to keep it air tight. You can see the back of this piece in one pic also.

KenWH

08-29-07, 05:32 PM

Here two more pics showing the outside. In one you can see the lip around the front baffle. The rear is set in the same amount also.

Kwikas

08-30-07, 04:35 AM

This is huge help Ken and it's much appreciated........thanks a lot!:)

As I see it there are really three things I need to concern myself about and none of them are about building the cabinet skins. That's straight forward enough I think..

What I don't fully understand is:

1. The internal bracing of the 4507A cabinet (where and how many)
2. Internal dampening (where and how much)
3. The 4 port lengths (I want 40hz)

As I understand it, all three have an effect on tuning. Also, the standard 4507 cabinet (NOT the 'A' version) utilises a 'baffle to back' brace just like your photo's showed. The 4507A cabinet however, has the driver in the middle of the baffle so I'm not sure whether the baffle in this cab has been braced to the back and if it has, where have JBL put the brace? And braces use up internal volume and so need to be considered.......etc etc

I'll come back when I've gotten some more replies from the people over at the Lansing Heritage forum. However, it looks as though he 4507A cab is kind of identical to the 4507....but the driver and ports have been centred on the 'A' version.

Cheers