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Discussion Starter #1
So I made a couple of posts and have done some more research regarding my basement home theater setup with the LMS-R 15" sub.. Right now the sub is tuned to 20 Hz and the output is "ok" but I'm thinking I should be able to get more out of it. More meaning I have too many nulls/void/modes in the room. I really can't move the sub anywhere else in the room as it is pretty large in size (the sub) and I want to keep it up front. Also I have more than a couple of listening positions for friends and family.


I downloaded Room EQ wizard and did some testing.. Should I post the waterfall output? Anything else? I can calibrate the soundcard but I can't calibrate the MIC as it is the newer Radio shack model and there isn't a file that I know of available for it. Also in my basement it is carpeted flooring with dry wall all around. I also have 2 Areas in the ceiling that hang a bit lower because of the vents being run for the AC in the above rooms. From research I was thinking of doing the following.. maybe someone can add to it?


1) buy another lms-R and use the ep4000 in 2 channel mode for awhile and then add another amp later. Not sure how much later I would add another amp so keep that in mind. Also keep in mind that the additional sub would be kept up front.. I would put one on the left and one on the right side of the center channel (as the boxes fix under the projector screen).


2) add some DIY bass traps.. I'm trying to get a price/quota for oc 705 now (plus it might be a fun DIY project). Was thinking of adding it in the left front corner and also above the listening position to block the parts of the AC vents that hang down...


3) get some sort of EQ... minidsp looks like it would be fun to mess around with but I'm not sure how I feel about buying plugins.. Can minidsp or other EQ's so phase shifts for 2 subs?


thanks,

mike
 

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What, if any, EQ are you applying now? Audyssey or anything like it? You may get some improvement by playing with the sub's phase setting and/or the distance setting in your AVR, as well as by moving the sub slightly. Can you post your FR and waterfall graphs from REW? That would help as well. While it's true that a second sub can smooth some of the room's modes and nulls, it's worth trying to get the FR as flat as possible with the single sub first. Also, please post your room dimensions (LxWxH).


BTW, you should be fine with the RS meter as a microphone as long as you're focused on the 10-200 Hz range with your measurements.


Ken
 

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Discussion Starter #4

Quote:
Originally Posted by Scott Simonian  /t/1420971/lms-r-15-in-6-cubic-foot-box-setup-in-room#post_22232811


I'd go for all three, if possible. Also, don't use OC705 for "bass traps". It's too dense. I'd make some panels with R-19 or something that is similarly soft and fluffy. Yes, the MiniDSP can EQ and phase shift two different subs. In fact it can for up to four of them, if I am not mistaken.

Thanks for the reply Scott! Always appreciated.. .from my reading online a lot of people recommend the oc705 though specifically for bass traps.. I'm all for using R-19 cause I believe you can get that at Lowes and such (where oc 705 has to be ordered from someplace magical it seems)... I'm still learning. I was actually just going to do some testing tonight with cushions to see if it makes any difference at all. Not sure if this is even worth testing (throwing some larger sized pillows in the corner of the room just to get an idea).


I'm really liking the technical aspects of the minidsp but they are based in Hong Kong and do not have any resellers in US. This is all personal preference but I wish someone in the states would carry it and I could call up and order... For 125 or so bucks it seems like it would solve some of the problems...


I guess I could always buy a receiver with XT32 in it.. looks like the onkyo 818 model (which is relatively new as of now) has it built in and isn't overpriced..


Mike
 

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Discussion Starter #5

Quote:
Originally Posted by K-Wood  /t/1420971/lms-r-15-in-6-cubic-foot-box-setup-in-room#post_22232810


What, if any, EQ are you applying now? Audyssey or anything like it? You may get some improvement by playing with the sub's phase setting and/or the distance setting in your AVR, as well as by moving the sub slightly. Can you post your FR and waterfall graphs from REW? That would help as well. While it's true that a second sub can smooth some of the room's modes and nulls, it's worth trying to get the FR as flat as possible with the single sub first. Also, please post your room dimensions (LxWxH).

BTW, you should be fine with the RS meter as a microphone as long as you're focused on the 10-200 Hz range with your measurements.

Ken

Ken,


Right now I'm doing very little EQ sub wise. I have a pioneer 1021-K receiver and it does have it's own room correction in but no EQ specifically for bass.. I forget if I can even adjust the distance setting for my sub (I can for the other 5 speakers though). I'll definitely double check tonight. http://www.pioneerelectronics.com/PUSA/Home/AV-Receivers/Pioneer+Receivers/VSX-1021-K/


Right now in its almost finished state the box I would guess weighs around 150 pounds.. so it is a pain to move.. I have tried moving it around the open (open meaning no furniture in the way) front left hand corner and didn't see any better results (actually seemed worse in most cases). I even placed the back of the sub against the left hand side wall so the sub was facing the right hand side, no good.


Also since I'm using a pro-amp and built the sub I'm not sure there is any way for me to adjust or change the phase at all...


I will try to get some graphs posted very soon of my ouput.. I will also try to get some pics of the room up.


thanks,

Mike
 

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Typically most rooms have 3 to 10 nulls and peaks, ranging from +-5 to +-15db.

Cubic and L-shaped rooms tend to be the worst for room-modes.

There is no room that has none... unless the walls are made of rice-paper and it's located at the precipice of Mount Thor.


Theoretically: +1 cone gives +3db, +1 amp gives another +3db (if they don't cancel each other out.)


The EP4k only has two phase options, in-phase and out (by flipping the wires manually at the terminals, hehe)


Having a good DSP for subs is a "must have" in most rooms.


Yes, post your REW FR. What is your LxWxH?
 

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Discussion Starter #7

Quote:
Originally Posted by BassThatHz  /t/1420971/lms-r-15-in-6-cubic-foot-box-setup-in-room#post_22234466


Typically most rooms have 3 to 10 nulls and peaks, ranging from +-5 to +-15db.

Cubic and L-shaped rooms tend to be the worst for room-modes.

There is no room that has none... unless the walls are made of rice-paper and it's located at the precipice of Mount Thor.

Theoretically: +1 cone gives +3db, +1 amp gives another +3db (if they don't cancel each other out.)

The EP4k only has two phase options, in-phase and out (by flipping the wires manually at the terminals, hehe)

Having a good DSP for subs is a "must have" in most rooms.

Yes, post your REW FR. What is your LxWxH?

The room dimentions are 14x20x8 but in the rear of the room it extends a bit (think L-shaped basement room)..


What are existing options for DSP/EQs/room corrections? My list so far would be


1) new receiver with XT32 (I don't think I want to go with anything less than XT32)... 800 bucks

2) the behinger FBQ2496 .. sort of requires PC as well... (price includes way cheap laptop form clearance bestbuy, 300+120) ... 420 bucks

3) the 400 dollar DSpeaker 8033 anti-mode bass thing.. I checked and the seller in the US listed the cheaper model as out of stock... 400+ bucks

4) minidsp is out as no US sellers of the product. Plus I would need laptop as #2 does..


My laptop I was testing with is just flat out too old (old celeron with 512 meg of memory).. I tried running room eq for linux as well on it and it was still just too slow.. So i'm guessing I need a new laptop for room eq testing..


Any other options?


thanks,

Mike
 

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Mike: The Behringer Feedback Destroyer can usually be found for less than $100. Before you conclude that you need a new laptop, you might try downloading the Behringer software to see if it will run on your laptop. As I understand it, the EQ is done in the device and the software merely provides a way to set the parameters, which are then loaded into the device.


Alternatively, is your laptop sufficient to run REW? If so, then you can generate the EQ filters in REW and load them directly into the BFD through its MIDI interface. I think you can do the same thing with the FBQ2496 if you decide to go that route.


Plug your room dimensions into Bob Golds Room Mode Calculator here to see where your likely modes and nulls are.


BassThatHz:
Quote:
Theoretically: +1 cone gives +3db, +1 amp gives another +3db (if they don't cancel each other out.)

Can you explain what you mean? Are you referring to the effect of adding another subwoofer?


Ken
 

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Quote:
Originally Posted by K-Wood  /t/1420971/lms-r-15-in-6-cubic-foot-box-setup-in-room#post_22235910


Mike: The Behringer Feedback Destroyer can usually be found for less than $100. Before you conclude that you need a new laptop, you might try downloading the Behringer software to see if it will run on your laptop. As I understand it, the EQ is done in the device and the software merely provides a way to set the parameters, which are then loaded into the device.

Alternatively, is your laptop sufficient to run REW? If so, then you can generate the EQ filters in REW and load them directly into the BFD through its MIDI interface. I think you can do the same thing with the FBQ2496 if you decide to go that route.

Plug your room dimensions into Bob Golds Room Mode Calculator here to see where your likely modes and nulls are.

BassThatHz:

Can you explain what you mean? Are you referring to the effect of adding another subwoofer?

Ken
Doubling cone area or doubling power theoretically gains you 3db each. So doubling both power and woofers gains you 6db. In practice though, you will place the subs in different parts of the room to smooth frequency response, so your net gain will never be +6db across the entire bass spectrum.
 

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If you are going the Behringer route, don't get a FBQ2496 or a DEQ2496, get a DCX2496 instead. The FBQ and DEQ won't have the all features you will need, like HP/LP XO's, Pre/Post Gain/Delay, and Phase, along with the EQ.

Also you can add up to 6 subwoofers with it, without requiring the purchase of yet another box.


The FBQ is a simplified version (10%) of the DEQ, the DCX has most of what the DEQ has (85%)... plus it adds the aforementioned stuff, which is more critical than optional to us DIY'ers.


The only advantage the MiniDSP has over the DCX is that it has adjustments down to 10hz rather than 20hz; and it can be cheaper... depending on what you need out of it. (Did I miss anything?)


Since you mentioned it, the MiniDSP requires a computer, a DCX does not.


The Anti-Mode is a waste of money IMO.
 

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Quote:
Originally Posted by mikeciccarelli  /t/1420971/lms-r-15-in-6-cubic-foot-box-setup-in-room#post_22232841


Thanks for the reply Scott! Always appreciated.. .from my reading online a lot of people recommend the oc705 though specifically for bass traps.. I'm all for using R-19 cause I believe you can get that at Lowes and such (where oc 705 has to be ordered from someplace magical it seems)... I'm still learning. I was actually just going to do some testing tonight with cushions to see if it makes any difference at all. Not sure if this is even worth testing (throwing some larger sized pillows in the corner of the room just to get an idea).

I'm really liking the technical aspects of the minidsp but they are based in Hong Kong and do not have any resellers in US. This is all personal preference but I wish someone in the states would carry it and I could call up and order... For 125 or so bucks it seems like it would solve some of the problems...

I guess I could always buy a receiver with XT32 in it.. looks like the onkyo 818 model (which is relatively new as of now) has it built in and isn't overpriced..

Mike

Rumor is that PE will start carrying the minidsp "soon"



Steve
 

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Discussion Starter #12
well I got rew on linux working so i was able to do some tests finally... i have xbmc loaded up on some old hardware... had to hook up old usb SB card cause output is via hdmi... i will post some graphs soon.. took me 3 hours to realize i needed regular java as fedora comes with the icedtea version... initial graphs look flat except

Just an fyi... all xt32 receivers are more than 1400 :) so i wont be getting xt32... I think i want to get another sub... prolly another lmsr... then get another amp later on... i might wait for minidsp if PE is going to sell it.
 

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Discussion Starter #13
Attached is the output.. These were done at -22 db FS sweep level under the calibrate screen... Otherwise I would always go too high on the output...


[ I removed the ROOM EQ graphs as they were wrong.. will update below ]


here is a brief layout of the room.. off to the right hand side would be the steps to go upstairs:




When just using the RS meter I'm getting up to 100 db pretty often with 1 15" LMS-R @ around 12 feet...
 

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You seem to be getting alot of infrasonic energy in the 5 to 10 Hz region. Is that your sub, or background noise? My guess would be background noise based on the fact that it doesn't decay in the waterfall like the other frequencies.
 

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Discussion Starter #15
Well just as an update... I added another lms-r 15" and put it up front to the right of the center channel (see picture above) and it didn't make much of a difference for my specific problem. Having spent a decent amount of 2 subs and pro amp I wanted it to work... I bought the new denon AVR-2113CI.. this seemed to finally fix my problem.


Ultimately I'd like to add another amp, 1 for each sub but really the ep4000 seems to be handling them nicely in stereo @ 4 ohms. I think with the EQ'ing the receiver is doing it doesn't make the amps clip nearly as much.. Yes I could have gone the cheaper route of just an EQ but I was worried it wouldn't fix all the of the problems.. All in all I wish I just would have gotten a receiver with Audyssey EQ XT but this project didn't start out to be where it is today..


I wonder how much there really is to the Audyssey XT hardware/software.. Is it more than just an EQ for the subs? Seems like it..


Mike
 

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You and i have a similar combo, sans the amp. The 1021k was not able to produce enough signal for my inuke before i changed some eq gain settings. This might be an issue for you? I have a 12in variant in a ported box, and i am able to hit peaks in 120ish pretty easily, along with extension down to 15hz decently.
 

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Discussion Starter #17

Quote:
Originally Posted by noobzorta  /t/1420971/lms-r-15-in-6-cubic-foot-box-setup-in-room#post_22283818


You and i have a similar combo, sans the amp. The 1021k was not able to produce enough signal for my inuke before i changed some eq gain settings. This might be an issue for you? I have a 12in variant in a ported box, and i am able to hit peaks in 120ish pretty easily, along with extension down to 15hz decently.

I bought an art cleanbox II to boost my signal.. I found that with this setup and other setups that I've used proamps in home theater that I needed the art cleanbox pro II... In the past I bought 1 for use in a different room with a crown xls 1500.. In that specific case I was hoping it would helped with the hum (ground loop) I was getting... Note that my amps I use do not have any DSPs (I think the inuke might let you tune "stuff" a bit more).


Couple of notes about cleanbox pro 2

1) Not sure it actually "cleans" up the ground loop hum.. I believe this actually was fixed some other way on my crown xls 1500.. just got lucky. With the ep4000 I had to ground the chassis to get rid of MOST of the ground loop/hum.. I still hear a bit of hum if I really crank the gains (which I don't have to do in most cases).


2) If you buy a cleanbox pro 2 it allows you to boost single to proamps so that you don't have to crank the output signal from the receiver (helpful if you want to use proamps in addition to "normal" all-in-one subs). For both the crown xls 1500 and the ep4000 I have cleanbox pro 2's.


I'm going to do some more testing tonight.. I had to finish up on the 2nd LMS-R box.. At around 10-12 feet from the sub I was getting around 105 db max with 1 15" but I really couldn't "hear" the bass.. It seemed like it was constantly out of phase with a single sub.. With the 2 15's I'm hoping to get a bit more now.. Regardless of the placement, number of subs and art cleanbox the biggest difference was just using Audyssey.. Reading the Audyssey page I could have gotten away wth MultiEQ but went with the Denon that has XT.


thanks,

Mike
 

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Couple things, audyssey also sets the delay for your sub to help with the eqing process. Two, the cleanbox pro II will start to roll-off around 20hz or a little below, so get rid of it and go for a more suitable signal booster/converter, or just buy the DCX2496 as others have suggested to get MORE EQ, MORE VERSATILITY, and 24 db's of signal boost should you need it. Running a sealed setup, with those subs, you are capable down to 10hz, dont rob yourself of that last 10hz...


The audyssey xt is def. a step up, and xt32 is an even BIGGER step up. Trust me, ive already done it. went from a denon 2311, to 3311, to now a 4311, as well as a cleanbox pro, to a tiny little eq box, to a berry mic2200, to now the dcx 2496 and the options I get are unreal. the DCX is a bit of a beast to figure out at first, and I actually bought an SMS-1 out of frustration as it REALLY does all the eqing for you, and you can see it on the screen, but alas, i havent decided to give up on the dcx yet, so I may just sell the sms-1.


Some other conversion boxes to check out if you dont want to go that route yet, are the henry matchbox HD, the samson s-convert, or the other that I all have in my back room right now and cant remember the name (maybe the ati mm1100).
 

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Discussion Starter #19
at this point the new receiver is running at -12 db so I'm guessing I could just completely ditch the pro II as it adds around 15 db I think max? And right now I have it around 1/2 to 3/4's gain... I should really just get rca to xlr cables and be done with it.. Ultimately it was never not having enough power or signal or low enough bass... it was completely bad room acoustics. I think since I've gone with the new denon I won't need a DCX at all.. just rca to xlr cables...


I built the subs for ported setup.. no plans on going to sealed as I seem to be getting plenty of
 

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Quote:
Originally Posted by mikeciccarelli  /t/1420971/lms-r-15-in-6-cubic-foot-box-setup-in-room#post_22284882


at this point the new receiver is running at -12 db so I'm guessing I could just completely ditch the pro II as it adds around 15 db I think max? And right now I have it around 1/2 to 3/4's gain... I should really just get rca to xlr cables and be done with it.. Ultimately it was never not having enough power or signal or low enough bass... it was completely bad room acoustics. I think since I've gone with the new denon I won't need a DCX at all.. just rca to xlr cables...

I built the subs for ported setup.. no plans on going to sealed as I seem to be getting plenty of
 
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