Wanted BIG BASS: Big room open to an even bigger room with lots of windows! - Page 3 - AVS Forum
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DIY Speakers and Subs > Wanted BIG BASS: Big room open to an even bigger room with lots of windows!
Oklahoma Wolf's Avatar Oklahoma Wolf 07:51 AM 04-30-2012
Looks like a decent design to me, as long as the driver specs are accurate.

Anything you get below 20Hz is gravy... I wouldn't count on an awful lot of extension below that number given the size of the room and the behavior of tapped horns below F3.

Chassmain's Avatar Chassmain 01:43 PM 04-30-2012
Quote:
Originally Posted by paulspencer View Post

Think about how you will install the driver. Current design looks like it needs a hatch. You can use the mouth for that if you place it in the front.

Was hoping I could install it right through the mouth without a hatch?

Will this be doable? Or should I reorientate the mouth so that I can install the driver straight on in through the mouth like your design?

Was planning on building it the way shown in Google sketchup to make construction the absolute easiest and allow me to shoot the horn into the corner in hopes of creating a larger operating horn path by using the corner of the room
Chassmain's Avatar Chassmain 02:26 PM 04-30-2012
Just purchased two 2010 Kicker CVXs with the dual 2 ohm voice coils. Went back and forth many times this morning/afternoon between pushing the buy button on the Fi Audio SSDs and Kicker CVXs.

In the end decided to go with the Kickers's by Mike's strong recommendation, a few other tapped horns I've seen using them, and the fact that I believe I have more accurate parameters for them.

Thinking about running these horns each off a single channel of my Emotiva XPA-5. At 300 Watts a piece I'm hoping they will still slam plenty hard, and if I need more I'll buy a bigger amp.

Now what should I use for DSP that uses balanced inputs?
beastaudio's Avatar beastaudio 02:35 PM 04-30-2012
the balanced mini DSP if you want to hook it up to your laptop to make adjustments, the Behringer dcx2496 if you are more of a button pusher like me
Chassmain's Avatar Chassmain 02:40 PM 04-30-2012
Quote:
Originally Posted by beastaudio View Post

the balanced mini DSP if you want to hook it up to your laptop to make adjustments

That's what I'm thinking, but what do people use to connect their XLR cables to the S + - terminals on the mini-dsp?
beastaudio's Avatar beastaudio 03:02 PM 04-30-2012
there are several phoenix-xlr connectors out there, or people are bare wiring it in there as well. This is what made me nervous but there are plenty of ways to fix that with no problems whatsoever.
Oklahoma Wolf's Avatar Oklahoma Wolf 03:17 PM 04-30-2012
Quote:
Originally Posted by Chassmain View Post

Just purchased two 2010 Kicker CVXs with the dual 2 ohm voice coils.

Now you're talking

Probably still the best tapped horn drivers on the market, right there.
Chassmain's Avatar Chassmain 07:20 AM 05-03-2012
Okay, miniDSP is all ordered with the balanced XLR to Phoenix cable adapters.

Now which plug-ins is best for my application?

2 Way Advanced
2 Way Advanced 2.1
4 Way Advanced

To begin with I'll only have 2 subwoofers that I'd like to EQ separately, but depending on how this works I may someday by another one or two. Does this mean I want the 4 way advanced so that I can EQ each separately?
JackNC's Avatar JackNC 09:06 AM 05-03-2012
Either one works, the difference is the 2-way advanced has two 2 way crossovers while the 4-way advanced has a single 4 way crossover with bandpass capability. For your app, this doesn't matter since you feed the same input to all subs, likely with just a low pass crossover. Using it in ADV mode, e.g. with BIQUAD programming, you can use the xover biquads for equalization purposes but it still doesn't matter because with both plug-ins you get a total of 4 xover outputs.
lilmike's Avatar lilmike 09:52 AM 05-03-2012
I use the 2-way advanced plugin.

The MiniDSP is 2-channels in, with 4 channels out. Each high-pass/lowpass and EQ section can be configured independently - in other words, you could highpass and EQ all 4 subs with a single MiniDSP and the 2-way advanced plugin.
Chassmain's Avatar Chassmain 07:50 PM 05-03-2012
Thanks, I'll just go with the 2-way advanced then...

What about hardware? What does everyone like to use to mount their speakers? I suspect there must be something much better than sheet rock screws.
Chassmain's Avatar Chassmain 01:29 PM 05-15-2012
Changed the design around slightly so that it'll be firing from the front to give access to load the driver through the mouth. Does anyone see any issues with this?



Other than that, the drivers have arrived, miniDSP is sitting in a box.

What else do I need as far as hardware/hurricane nuts to mount the driver? Where I will be mounting the driver from the back so that the front of it is against the MDF will I need some gasket or sealing tape or something along those lines?

Somebody else will be building this for me so I want to make sure I have everything all lined up for a seamless build.

I need:
6 sheets of 3/4" medium density fiber board
4 tubes of PL premium

What else???

Thanks guys!
LL
kgveteran's Avatar kgveteran 02:09 PM 05-15-2012
Subscribed !
radman12's Avatar radman12 02:19 PM 05-15-2012
terminal cup. wiring. cant wait to hear your impressions, I know i love my 2 cvx15 tapped horns; they are beyond impressive
NEO Dan's Avatar NEO Dan 02:35 PM 05-15-2012
You are pushing very low with your design, there is a trade in sound quality as you attempt a wide bandwidth TH, you create a large group delay peak in the upper bass. If not for problems like this big TH's like your design would be more common. If you want the extension you can reverse the tapper and stuff the first half for much improved group delay and impulse response = better sound quality.

Stock up on tweeters if you like it loud, they are easily cooked.
lilmike's Avatar lilmike 04:06 PM 05-15-2012
Quote:
Originally Posted by Chassmain View Post

Changed the design around slightly so that it'll be firing from the front to give access to load the driver through the mouth. Does anyone see any issues with this?



Other than that, the drivers have arrived, miniDSP is sitting in a box.

What else do I need as far as hardware/hurricane nuts to mount the driver? Where I will be mounting the driver from the back so that the front of it is against the MDF will I need some gasket or sealing tape or something along those lines?

Somebody else will be building this for me so I want to make sure I have everything all lined up for a seamless build.

I need:
6 sheets of 3/4" medium density fiber board
4 tubes of PL premium

What else???

Thanks guys!

There is not much mechanical noise from the CVX, so no issues there. However, the shorter L34 may alter the response ahead of the 5th harmonic (it will deepen that trough) and it will change the acoustic loading of the horn. Also - unloading the cone in the mouth like that will alter the response. End-firing may be a better match to the model.

Hurricane nuts work OK, but have to be installed properly. Degrease them, then glue them into place. There are detailed instructions explaining how I do it in my F-20 build instructions. I still have encountered an issue or two. I am experimenting with threaded inserts now. As far as gasket material I have had good luck with Duct Seal. I typically route a shallow rabbet to center the driver over the cutout in my bafffes, it makes installation of the driver lots easier. With 3/4" material and the CVX frame, at least 1.5" long screws are required. I typically use socket-head capscrews.

Moisten the MDF before gluing it with PL. PL will not stick well otherwise. A quick wipe of the gluelines with a damp rag is all that is needed.

I use speakon 2-conductor terminals - they are cheaper than cups and are a lot more fool-proof.

@ NEO Dan - this one is really not tuned that low - with a single fold, he's limited by the 8' length to a ~23 Hz tune. Group delay is in the 60 ms range at 24 Hz, with a sharp peak near 60 ms at 92 Hz. Should be alright.
Chassmain's Avatar Chassmain 05:34 PM 05-15-2012
Quote:
Originally Posted by radman12 View Post

terminal cup. wiring. cant wait to hear your impressions, I know i love my 2 cvx15 tapped horns; they are beyond impressive

REALLY!?! Do you have a build thread or someplace you've written down your impressions. I'd love to hear from you and what you think about these drivers, and in particular your horns!

Quote:
Originally Posted by NEO Dan View Post

You are pushing very low with your design, there is a trade in sound quality as you attempt a wide bandwidth TH, you create a large group delay peak in the upper bass. If not for problems like this big TH's like your design would be more common. If you want the extension you can reverse the tapper and stuff the first half for much improved group delay and impulse response = better sound quality.

I have rather capable mains, and was planning on crossing these fellas over around 80 hz, so at those wavelengths I don't think group delay will make much of a difference. Maybe I'm wrong here?

Quote:
Originally Posted by lilmike View Post

There is not much mechanical noise from the CVX, so no issues there. However, the shorter L34 may alter the response ahead of the 5th harmonic (it will deepen that trough) and it will change the acoustic loading of the horn. Also - unloading the cone in the mouth like that will alter the response. End-firing may be a better match to the model.

Okay… Okay… Okay! Not one, but three reasons why it should be end firing! I'll change it back over big guy, no problems there, had a weak moment when I was moving these massive drivers around and got scared about how I would mount them. And therein the question… Will I be able to mount these by sticking my hand/driver in through the mouth or will I need to make an access point somewhere?

Quote:
Originally Posted by lilmike View Post

Hurricane nuts work OK, but have to be installed properly. Degrease them, then glue them into place. There are detailed instructions explaining how I do it in my F-20 build instructions. I still have encountered an issue or two. I am experimenting with threaded inserts now. As far as gasket material I have had good luck with Duct Seal. I typically route a shallow rabbet to center the driver over the cutout in my bafffes, it makes installation of the driver lots easier. With 3/4" material and the CVX frame, at least 1.5" long screws are required. I typically use socket-head capscrews.

Will definitely read over your F-20 build instructions again to make sure I'm up to speed on everything. If the hurricane nuts only work so so, should I give the threaded inserts a try? I'm up for using whatever will work best.

And… Drumroll please how about a little eye candy!

LL
lilmike's Avatar lilmike 06:41 PM 05-15-2012
Though it is a heavy driver, I had no real issues mounting my CVX 15 in the last tapped horn I built. Don't fight gravity, it will win every time. Sent ya details in an email. The horn is plenty wide to reach around and behind the driver, using socket head capscrews will also make things easier.

If I recall, the driver is set back about 5.25" from the mouth, plus the 7.5" to the driver's center. Should not be too bad. Mine was further back than that, and the horn baffle was even narrower.

Not sure on the inserts yet. Have not had a chance to use them (that horn is not folded yet). I bought some zinc hex drive inserts with a flange, and plan to degrease them, then glue them into place. I tried to strip them or pull them through the wood with ridiculous levels of torque from my impact driver, no luck. I was able to unscrew them though. A little PL should help that.
LTD02's Avatar LTD02 07:02 PM 05-15-2012
why not mount your driver before attaching the final cabinet panel??? are you just trying to make things difficult for yourself? :-)

while i haven't modeled up precisely what you have there, my gut tells me that you are on the right track with your final design.
kgveteran's Avatar kgveteran 07:05 PM 05-16-2012
You're going to like working with the MiniDSP. Making adjustments on the fly, and seeing the results with whatever you are going to measure with is the coolest. Balanced is the way to go. Get ready to ground it to the outlet if you are getting serious hum. Enjoy !
Chassmain's Avatar Chassmain 03:37 PM 05-17-2012
Quote:
Originally Posted by LTD02 View Post

why not mount your driver before attaching the final cabinet panel??? are you just trying to make things difficult for yourself? :-)

while i haven't modeled up precisely what you have there, my gut tells me that you are on the right track with your final design.

Yeah, yeah... give me a hard time all you want for making it difficult on myself . Just keeping access in mind in case I blow the sucker up someday. But yes, you're probably right I should just mount it before putting on the top!

LTD, thanks for all your help along the way. I have you as a large part the thank for the design and inspiration of getting here!

Now I just need to get the suckers built!
Chassmain's Avatar Chassmain 03:40 PM 05-17-2012
Did I say I wish these were already built!



LL
jmcomp124's Avatar jmcomp124 09:12 PM 05-17-2012
Quote:
Originally Posted by Chassmain View Post

Hey there bass fanatics! Been reading through this forum for many months, drooling at the many impressive DIY subwoofers, thinking about/designing/modeling my own, and through the process coming up even more confused with what I should do.

So what should I do with $1500 bucks to buy drivers, amps, and wood to give me all sorts of tight, impacting bass that'll fill my 23’ x 25’ (6000 ft.³) room for home theater use, but still maintain some musicality while I'm jamming to some tunes. The speakers these will be enhancing are Bowers & Wilkins 801 Series 2. Although not the highest SPL/most efficient speakers in the world they sound marvelous and I want my new subwoofers to match the musicality of these while having plenty of headroom for home theater use.

I've bounced back and forth between multiple dual opposed 15s, sealed LMS Ultras, multiple ported 15s, THT or F20 horn designs. I really can't figure out which gives me the best combination of SPL, sound quality, and ultralow frequency bass.

What would you do for my room?
Budget: $1,500
Desire: Musicality, Impacting Bass, Good looks
Room size: 23’ x 25’ (6000 ft.³) with double doors separating an adjoining 10,000 ft.³ room

Thanks guys!

How about a few pictures to put this all into context. Notice all the windows and that the room overall (except for the messiness) looks kinda nice. I don't want the subwoofers to too much overpower the visual awesomeness of my room.

Just looked through your link and seriously one of the coolest people I have had the opportunity to be acquainted (just reading through). Isn't it great that a hobby sometimes brings people together .
Chassmain's Avatar Chassmain 08:17 AM 05-18-2012
Quote:
Originally Posted by jmcomp124 View Post

Just looked through your link and seriously one of the coolest people I have had the opportunity to be acquainted (just reading through). Isn't it great that a hobby sometimes brings people together .

Hey man, thanks, really means a lot! Life has thrown quite the crazy obstacle course of challenges at me, but I'm pushing on and making the best of every day. I just feel so fortunate to have the capabilities that I have and a wonderful network of friends/family that makes each day something to really look forward too.

As I've worked on various projects throughout the years and gotten in with the whole AVS community I'd have to definitely include all you guys into that network of friends that really makes life better.

Thanks guys!

Probably should update the blog one of these days here!
jmcomp124's Avatar jmcomp124 11:20 PM 05-19-2012
Quote:
Originally Posted by Chassmain View Post

Hey man, thanks, really means a lot! Life has thrown quite the crazy obstacle course of challenges at me, but I'm pushing on and making the best of every day. I just feel so fortunate to have the capabilities that I have and a wonderful network of friends/family that makes each day something to really look forward too.

As I've worked on various projects throughout the years and gotten in with the whole AVS community I'd have to definitely include all you guys into that network of friends that really makes life better.

Thanks guys!

Probably should update the blog one of these days here!

Most welcome. You said something very important that is really the key during difficult times "a wonderful network of friends/family". Take care and enjoy the hobby. Very few like it
Chassmain's Avatar Chassmain 06:44 PM 05-31-2012
Howdy fellows, been a little bit quiet these past few weeks, but guess what, huge awesomeness happened today today because my bad boys are built!

Let's see, just over 5 sheets of plywood, 3 tubes of PL, 300 something drywall screws, a couple Kicker 15 inch CVXs, and about 10 hours of labor.

Quad Horn #1 Front


Quad Horn #1 Rear


Quad Horn #2 Front


Quad Horn #2 Rear


Now I'm sitting here tonight totally unable to contain myself because I want to listen to these so damn bad, but they are so freaking huge there is no way I can get them in place with a single person.

Tomorrow will be all about finishing them to blend in with the room and firing them up for the weekend!

Any thoughts on what I should get for an amp? Really thinking about a used Crown K2 to send them about 1000 W per channel, and it's silent fanless design.
LL
LL
LL
LL
jmcomp124's Avatar jmcomp124 08:18 PM 05-31-2012
Quote:
Originally Posted by Chassmain View Post

Howdy fellows, been a little bit quiet these past few weeks, but guess what, huge awesomeness happened today today because my bad boys are built!

Let's see, just over 5 sheets of plywood, 3 tubes of PL, 300 something drywall screws, a couple Kicker 15 inch CVXs, and about 10 hours of labor.

Quad Horn #1 Front


Quad Horn #1 Rear


Quad Horn #2 Front


Quad Horn #2 Rear


Now I'm sitting here tonight totally unable to contain myself because I want to listen to these so damn bad, but they are so freaking huge there is no way I can get them in place with a single person.

Tomorrow will be all about finishing them to blend in with the room and firing them up for the weekend!

Any thoughts on what I should get for an amp? Really thinking about a used Crown K2 to send them about 1000 W per channel, and it's silent fanless design.

Cool
If you can somehow mask the fan noise, I would suggest the best kept secret Crown CE4000
Chassmain's Avatar Chassmain 03:02 PM 06-02-2012
You may laugh, and you most certainly will feel my pain.

I made noise, but it was very, VERY short-lived and I'm still scratching my head/sick to my stomach at the wake of disaster my little experiment brought. Don't really think I did anything really that wrong, but a combination of misfortunate events blew up my amplifier, my left front BW801, and possibly one of my horns.

Let's see, what all happened!

We finished building the horns on Thursday and were in the process of finishing them on the back deck Friday so I figured what the heck, let's make these things move! So, I grabbed a 30 foot wire, plugged it into the outlet of my front left speaker and fired up REW to send a 30 Hz tone. Now I knew I needed to be super careful because I was running these through a full range channel with no highpass filter so I figured I'd just keep it simple and test out a few 23-80 Hz tones. So I fired it up, ran a few sweeps, and gradually increased the volume while I kept an eye on the driver. It was amazing how much volume it was putting out with very little driver movement. Figured I'd drop down a few hertz and find the low-frequency knee. At this point I was pushing things a little harder, but still not too crazy, and then I heard a loud click and no sound. Went back to my amplifier and noticed it was in protect mode, figured no biggie, and turned the tone off, turned my amplifier back on only to hear a real low 60 Hz hum and it went into protect mode again. Things started smelling funny outside, so I figured **** somehow I’d blown the sub. So, freaking out I unhooked the amplifier from the sub, rewired it to my left 801 and turned my amplifier back on to figure out if I'd blown the sub or not only to hear that same 60 Hz hum through my front left speaker and find my amplifier going into protect mode. Well crap, looks like I just blew up my amplifier. Only thing I can fathom is when I was playing the test tones the 4 ohm impedance of the subwoofer dropped down enough to be more than my amplifier could handle and instead of going into protect mode it just blew the hell up. Then, me being stupid and wiring my 801 back into it blew up the base driver in my 801 (at least I hope that's all it did).

Still trying to figure out how the heck this all happened. I mean my Emotiva amp should be able to play that sub at moderate volumes without blowing up right?

Now I need to find another amp to test my horn and make sure it's okay, must say I'm a little bit gun shy to use my Emotiva amp after what I just experienced.

Oh well, screw it :-) they're pretty dang impressive!
cookieattk's Avatar cookieattk 03:21 PM 06-02-2012
did u ohm the speaker before plugging it in are u sure u didn't put a 1ohm load on the amp and toast it.
Chassmain's Avatar Chassmain 03:23 PM 06-02-2012
Yeah, put a fluke 189 across the speaker terminals and it read 4.3 ohms
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