BIG BOX sub – 85 feet^3 - AVS Forum
Forum Jump: 
 
Thread Tools
post #1 of 25 Old 04-05-2006, 10:39 AM - Thread Starter
Member
 
VasiliyK's Avatar
 
Join Date: Apr 2006
Location: Vancouver WA
Posts: 30
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Idea is to build the sub between the screen and front wall. The room dimensions is 17’*16’*9’ so I decide to make a fake wall to mask the speakers and bass traps, put the screen on it and build the sub box inside that wall. The size of the box is 11 feet wide 8 feet high and 1 foot deep. For driving this sub I will use 4 of AV15 speakers
I'm in process of making the box and have a question – how much insulation(for sound absorption ) I’ll need to put inside?
Any help really appreciated! :)
VasiliyK is offline  
Sponsored Links
Advertisement
 
post #2 of 25 Old 04-05-2006, 10:48 AM
AVS Special Member
 
ssabripo's Avatar
 
Join Date: Feb 2004
Location: Plantation, Floriduh
Posts: 6,006
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 13
good luck Vassily... :)

you don't need to muff the sound with too much insulation....for a box that size, a some foam with do well all around the inner walls (at around 1"). If you are going to use the "pink" insulation fiber used in homes (found at home depot, etc), then I suggest you use a single layer all around the inner walls again, and perhaps even take off 1/2-1/3 so that you dont over stuff it and cause the sound to be muffed.

although in a box that size you should be fine.

4 AV15's will be an IMPRESSIVE box!! :D I just got done with one, and can only imagine what 4 will sound like:
http://server4.ihostphotos.com/imgt/39017.jpghttp://server4.ihostphotos.com/imgt/39018.jpg
ssabripo is offline  
post #3 of 25 Old 04-05-2006, 11:01 AM
Senior Member
 
BlakeN's Avatar
 
Join Date: Aug 2005
Posts: 276
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
I suggest you brace the heck out of it. If your screen is attached and it vibrates at all your picture will be blury. Cool Idea though I cant wait to see it. Take lots of pictures.
BlakeN is offline  
post #4 of 25 Old 04-05-2006, 11:17 AM - Thread Starter
Member
 
VasiliyK's Avatar
 
Join Date: Apr 2006
Location: Vancouver WA
Posts: 30
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Thanks SSABRIPO that helps. First I’m planning to fit 2 of AV15’s with the room to add two more later.

BlakeN - with those bracings the box will survive a direct hurricane hit :)
I’ll post some pictures later.
VasiliyK is offline  
post #5 of 25 Old 04-05-2006, 11:39 AM
AVS Special Member
 
Tom Brennan's Avatar
 
Join Date: Apr 2002
Location: Chicago
Posts: 1,953
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Vented box? If so and if used as a subwoofer rather than a woofer you probably need no damping material at all inside the box.
Tom Brennan is offline  
post #6 of 25 Old 04-05-2006, 11:50 AM
Advanced Member
 
SightSeeker1's Avatar
 
Join Date: Dec 2005
Location: MD
Posts: 573
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 12
I can't even imagine how loud that will be. LOL Did you model it to that size with software?
SightSeeker1 is offline  
post #7 of 25 Old 04-05-2006, 11:55 AM - Thread Starter
Member
 
VasiliyK's Avatar
 
Join Date: Apr 2006
Location: Vancouver WA
Posts: 30
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by Tom Brennan
Vented box? If so and if used as a subwoofer rather than a woofer you probably need no damping material at all inside the box.
It’s not vented and will be used as a sub. Thanks ;)
VasiliyK is offline  
post #8 of 25 Old 04-05-2006, 12:07 PM - Thread Starter
Member
 
VasiliyK's Avatar
 
Join Date: Apr 2006
Location: Vancouver WA
Posts: 30
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by SightSeeker1
I can't even imagine how loud that will be. LOL Did you model it to that size with software?
I didn’t model it with software. Originally it was to be IB setup but when it come closer to built time I decided to use the space behind the screen. Also with the drivers located under the screen close to the main towers that plan helps with phase issue (i hope :D )
VasiliyK is offline  
post #9 of 25 Old 04-05-2006, 01:21 PM
AVS Special Member
 
Thomas-W's Avatar
 
Join Date: Oct 2000
Location: 5280'
Posts: 1,372
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 14
Cover all the interior surfaces with 6"-8" thick batts
Thomas-W is online now  
post #10 of 25 Old 04-05-2006, 01:49 PM - Thread Starter
Member
 
VasiliyK's Avatar
 
Join Date: Apr 2006
Location: Vancouver WA
Posts: 30
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by Thomas-W
Cover all the interior surfaces with 6"-8" thick batts

The total interior space will be 12in deep inside (13in external) so can’t use 6â€-8†for interior. :eek:
I’ll post some pics soon hope that will help. Thanks Thomas-W :)
VasiliyK is offline  
post #11 of 25 Old 04-05-2006, 02:23 PM - Thread Starter
Member
 
VasiliyK's Avatar
 
Join Date: Apr 2006
Location: Vancouver WA
Posts: 30
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
VasiliyK is offline  
post #12 of 25 Old 04-05-2006, 03:10 PM
AVS Special Member
 
Tom Brennan's Avatar
 
Join Date: Apr 2002
Location: Chicago
Posts: 1,953
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Even in a sealed box absorbent material is only needed if you want to "increase" the size of the enclosure.

At subwoofer only frequencies fiberglass batting or foam will not absorb sound and since no midrange material is being reproduced there's no need to absorb midrange sound waves.

Note that historically most IBs and vented systems that used batting used it to absorb MIDRANGE and upper bass reproduced by woofers (less it be reflected back to the cone and produce distortion) and that often only three of the six sides were lined, that being sufficient to kill midrange reflections.
Tom Brennan is offline  
post #13 of 25 Old 04-05-2006, 03:40 PM
AVS Special Member
 
M NEWMAN's Avatar
 
Join Date: Nov 2000
Location: dallas,tx. usa
Posts: 3,718
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by VasiliyK
I didn’t model it with software. Originally it was to be IB setup
At 88 cu ft, its still an infinite baffle alignment as far as the woofers are concerned. Just a little less infinite than most IB setups, but your final box Qt will still be critically damped at .577 or less.

Mike
M NEWMAN is offline  
post #14 of 25 Old 04-05-2006, 04:23 PM
AVS Special Member
 
Thomas-W's Avatar
 
Join Date: Oct 2000
Location: 5280'
Posts: 1,372
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 14
Quote:
The total interior space will be 12in deep inside (13in external) so can’t use 6â€-8†for interior.
Okay, go ahead and fill it up since the drivers will be so close to the rear-wall.

You're a little over 4 times summed Vas. That will bump the "Q" up by a multiplier of ~1.4. So not a Qts = Qtc situation, but it should sound much better than a small sealed box..... :cool:
Thomas-W is online now  
post #15 of 25 Old 04-05-2006, 05:05 PM
AVS Special Member
 
SteveCallas's Avatar
 
Join Date: Jun 2004
Posts: 6,713
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Liked: 17
How deep are the drivers you are going to use? 1' depth seems like it may be a bit detrimental.
SteveCallas is offline  
post #16 of 25 Old 04-05-2006, 06:47 PM
Member
 
crippledchicken's Avatar
 
Join Date: Feb 2006
Location: POPLAR BLUFF MO.
Posts: 46
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
wow! that's bigger than my whole living room! :D
crippledchicken is offline  
post #17 of 25 Old 04-05-2006, 07:32 PM
AVS Special Member
 
crackyflipside's Avatar
 
Join Date: Oct 2005
Location: Miami, FL
Posts: 2,186
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Freeking SPECTACULAR! Get those pics up or you will be greeted tonight by an angry mob!
crackyflipside is offline  
post #18 of 25 Old 04-06-2006, 06:19 AM
Advanced Member
 
SightSeeker1's Avatar
 
Join Date: Dec 2005
Location: MD
Posts: 573
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 12
Quote:
Originally Posted by Tom Brennan
At subwoofer only frequencies fiberglass batting or foam will not absorb sound and since no midrange material is being reproduced there's no need to absorb midrange sound waves.
How come some sub manufactures put insulation in their subs then? SVS comes to mind since someone posted pics of the plus 2 interior recently.

Not trying to argue, just wondering. :)

I lined my walls with the egg crate foam just because I saw some ported subs with it. Also EM reviewed the EP-500 and said he wished they lined all the walls instead of just the sides/top/bottom.
SightSeeker1 is offline  
post #19 of 25 Old 04-06-2006, 09:20 AM
AVS Special Member
 
Tom Brennan's Avatar
 
Join Date: Apr 2002
Location: Chicago
Posts: 1,953
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
SS1----The use of absorbent material can give an increase in apparent box size, theoretically of 1.4 but Eargle says in actual practice more like 1.2.

Absorbent material can damp standing waves in an enclosure but only waves in an enclosure with a dimension equal to one or more wavelengths. Since a 100hz wave is 11.3' long very few subwoofers will benefit from such intended treatment.

However WOOFERS, which are often run up past the 1000-2000hz range can benefit from such treatment.

I think many people use stuffing without having thought out what the stuffing is intended to do or whether it can actually do what is intended.
Tom Brennan is offline  
post #20 of 25 Old 04-06-2006, 09:25 AM
Advanced Member
 
SightSeeker1's Avatar
 
Join Date: Dec 2005
Location: MD
Posts: 573
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 12
That makes sense. Well hopefully it will act as an increase for me since I never calculated the port into my internal space when I started. Now only if my speaker will come in. Due tomorrow finally but we will see.
SightSeeker1 is offline  
post #21 of 25 Old 04-06-2006, 10:45 AM - Thread Starter
Member
 
VasiliyK's Avatar
 
Join Date: Apr 2006
Location: Vancouver WA
Posts: 30
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Some pcs - like I sad : :)

Frame core - 2 layers of glued drywalls + frame support screwed to the studs
http://server4.ihostphotos.com/imgt/45655.jpg

Trying to put things together
http://server4.ihostphotos.com/imgt/45654.jpg

Supervisor
http://server4.ihostphotos.com/imgt/45656.jpg

What are you doing! take this one!!!
http://server4.ihostphotos.com/imgt/45657.jpg

Half way done
http://server4.ihostphotos.com/imgt/45658.jpg

Another point of view
http://server4.ihostphotos.com/imgt/45659.jpg

Glued corner
http://server4.ihostphotos.com/imgt/45660.jpg

Close view
http://server4.ihostphotos.com/imgt/45661.jpg

The glue
http://server4.ihostphotos.com/imgt/45662.jpg

Thanks a lot to everyone for the answers!
VasiliyK is offline  
post #22 of 25 Old 04-06-2006, 11:26 AM - Thread Starter
Member
 
VasiliyK's Avatar
 
Join Date: Apr 2006
Location: Vancouver WA
Posts: 30
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Tom Brennan – thanks for the detailed explanation. Because the 'pink staff' is already in my house, I’ll put some (hopefully that will increase my apparent box size closer to the IB).

P.S. I will update this tread with new pics later.
VasiliyK is offline  
post #23 of 25 Old 04-06-2006, 12:15 PM
AVS Special Member
 
PLincoln's Avatar
 
Join Date: Nov 2003
Posts: 1,862
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by VasiliyK
pink staff
i couldn't resist quoting that for posterity... :)
PLincoln is offline  
post #24 of 25 Old 04-06-2006, 12:18 PM
AVS Special Member
 
PLincoln's Avatar
 
Join Date: Nov 2003
Posts: 1,862
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by VasiliyK
increase my apparent box size closer to the IB).

P.S. I will update this tread with new pics later.
while it might increase the box size, another advantage of an optimal IB is that the rear of the driver is relatively far away from any walls/obstructions, allowing the rear wave to dissapte and not get reflected back into the driver
PLincoln is offline  
post #25 of 25 Old 04-06-2006, 03:40 PM - Thread Starter
Member
 
VasiliyK's Avatar
 
Join Date: Apr 2006
Location: Vancouver WA
Posts: 30
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by need4speed
while it might increase the box size, another advantage of an optimal IB is that the rear of the driver is relatively far away from any walls/obstructions, allowing the rear wave to dissapte and not get reflected back into the driver

You are right. :confused: If I will not be satisfied with the results, I’ll go back to the IB setup :eek:
VasiliyK is offline  
Closed Thread DIY Speakers and Subs

User Tag List

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off