[G E]

Hello!

I am interested in acoustically treating my primary listening space.  It is a small room, 11.5 x 14.5 with a 9 foot ceiling, half inch gypsum surfaces for walls and ceilings and heavy carpet and pad over concrete.  Lots of fiberglass insulation in the walls and ceiling from when I built this room.  No windows and two doors at the left front and back corners.  The electronics stack is in a 3 x 8 walk in closet.

I have some time off around the holidays and thought this would be a good project to keep me busy.

A couple questions:

1) Is it best to use OC 703 or OC 705 for bass traps?

2) I have the option to build the traps to run from floor to ceiling and placed diagonally in the corners.  Will this be much of an improvement over 2 x 4 panels?

3) For a room this small is 2" thickness enough or should I go to 4" or even 6" ?

4) For absorption panels should I stay with OC 705 or is the 703 better for this purpose?  There are minimum order requirements I have to work with.

5)  Any other tips for making this room as good as possible?

This is a dedicated room used primarily for surround sound music and drinking home brew.  WAF is not a factor, so pretty much anything goes (within limits). 

Thanks for any suggestions, and thanks go out to everyone who has got me this far, particularly those videos by Ethan on YOU Tube. 

G E

[bpape]

You'll want to watch doing the vertical corners since both the left front and left back are taken up by a door.  You want to maintain symmetry left to right in front of you.

703 will work fine for all of the applications.  For bass control, if you want them to reach really deep, you'll want them to be 6" thick and at that thickness, 703 will perform just as well as 705 for half the money.

Reflection panels can be just 2". 

Bryan

[Alwayswantmore]

What is your budget? Granted, DIY holds the potential to save a few bucks. but if money is not the primary issue, you may want to consider GIK. Bryan and Glenn were very helpful designing treatments for my very small room. I am 110% satisfied with both the look and sound. Here's a link to my blog on my room. Since this was written I've ungraded to newer Omega speakers. The sound is spooky real. Feel free to PM if you want any more info. Kent -- http://www.audiocircle.com/index.php?topic=57818.60

[G E]

703 will work fine for all of the applications.  For bass control, if you want them to reach really deep, you'll want them to be 6" thick and at that thickness, 703 will perform just as well as 705 for half the money.

Bryan

Hi Bryan,
Thank you for your response.  For corner traps, either diagonal across the corner or adjacently at a 90 degree angle, will 2 x 4 panels be sufficient or will floor to ceiling traps take it to the next level?

Thanks in advance!
Greg

[G E]

What is your budget? Granted, DIY holds the potential to save a few bucks. but if money is not the primary issue, you may want to consider GIK. ...

Hi Kent,
Thanks your response.  Budget is always a factor in my projects, usually sooner than later!  I was hoping to start out with a few hundred bucks via DIY and see where that takes me.  My skillset is fairly good, maybe not up to "This Old House" or "New Yankee Workshop" levels, but I can safely run a table saw, hang rock, mud, etc.

I have looked at several articles and videos and there are quite a few variants on traps and absorbers.  One in particular was interesting:  A frame is built, fabric stretched across it, the fiberglass bat rests on the frame and fabric and a 2nd layer of fabric is fastened to the frame, and this holds the bat against the frame.  The frame spaces the bat away fromth wall several inches. I already have a couple ideas for enhancing this version, but before I do, is a trap more effective if it has a rigid backing like plywood or hardboard?  Does the same go for absorption panels?

Greg

[Alwayswantmore]

What is your budget? Granted, DIY holds the potential to save a few bucks. but if money is not the primary issue, you may want to consider GIK. ...

... is a trap more effective if it has a rigid backing like plywood or hardboard?  Does the same go for absorption panels?

No, traps are open so sound makes it to the wall, especially if the trap is on angle to corner or placed away from a wall. All GIK traps have space behind the sound absorbsion materials. If you think about it, sound waves have zero velocity when they hit a hard surface and bounce back (at point of contact -- just like a pool ball hitting a bumper). There is a lot of science behind this -- the longer the sound wave, the more space from wall & more absorbsion capability required to capture that wave length. So hard backings are not used on standard traps.

[youngho]

2) I have the option to build the traps to run from floor to ceiling and placed diagonally in the corners.  Will this be much of an improvement over 2 x 4 panels?

3) For a room this small is 2" thickness enough or should I go to 4" or even 6" ?

4) For absorption panels should I stay with OC 705 or is the 703 better for this purpose?  There are minimum order requirements I have to work with.

5)  Any other tips for making this room as good as possible?

This is a dedicated room used primarily for surround sound music and drinking home brew.  WAF is not a factor, so pretty much anything goes (within limits). 

#2. Depends on whether treating those corners more extensively results in fewer corners being treated...
#3. 4-6" (or more) for broadband absorption
#4. For absorption panels, it depends on whether you want broadband or not. I think of thinner panels almost like equalizers to turn down the mids and highs for reflected sound, leaving more of the frequency range associated with a perception of spaciousness intact. Some folks argue for the use of broadband absorption if it is to be used at all.
#5. Broadband absorption on the rear wall directly behind the listener(s). Broadband absorption on the front wall between the L/C/R speakers. Consider some diffusion elements, especially to the sides in the back, maybe on the ceiling at the first reflection point. Thick carpet with perforated backing on top of a thick felt pad on the flooor.

[bpape]

703 will work fine for all of the applications.  For bass control, if you want them to reach really deep, you'll want them to be 6" thick and at that thickness, 703 will perform just as well as 705 for half the money.

Bryan

Hi Bryan,
Thank you for your response.  For corner traps, either diagonal across the corner or adjacently at a 90 degree angle, will 2 x 4 panels be sufficient or will floor to ceiling traps take it to the next level?

Thanks in advance!
Greg

All depends on what you're doing elsewhere in the room.  If this is your only bass control, then the extra is worth it - though doing 8' in 2 corners may not be as good as 4' in 2 corners and the balance elsewhere for specific issues.

If even more is required, then you may need to consider doing some sort of facing on some of the panels which are primarily for bass control to limit the upper mid and high frequency absorption to keep things better balanced and not make it too dead.

I wish there was a definite, solid answer I could give you but every room is different.  Everyones' preferences are different.

Bryan

[G E]

Thank you for all of your suggestions.  This morning I picked up 24 bats of 2 inch OC 703 and stacked them up in the basement next to where room treatments will begin Friday.  It looks like quite a bit, but I suppose it gets used up faster than one expects.  Hopefully I can remember to take a few pics and post them here as well.

Greg

[G E]

I have finished construction of the frames for the four bass traps.  They are 24" x 96.5" inches.  They are a variant of Joel DuBay's construction technique found here:  http://www.youtube.com/watch?v=iyYUpkpL0gw&feature=related 

My frames are double the length and I also added two "shelves", one at the base of the frame, the other at a height of 48" to better carry the weight of four OC 703 bats, 2 above, two below.  I'll try to post some pics.

Here is my question:  I plan to use 6 "dots" of Liquid Nails to bond the first layer of OC 703 to the frame (in this plan the OC 703 rests on top of the frame) and then 6 more dots of Liquid Nails around the periphery to bond the 2nd OC 703 sheet to the first.  Is there any reason I should use adhesive spray instead of Liquid Nails for either of these processes?

BTW, I found some muslin fabric at Joann Fabric store and it was somewhat cheaper than WalMart.  A day later I saw Joann Fabric had a coupon for 40% off one item, so may return muslin and upgrade to burlap!

ge

[richidoo]

The adhesive spray will clog the airspaces of the fg, so use dots for laminating them together.

[mfsoa]

See some pics here:

http://www.audiocircle.com/index.php?topic=63439.msg574023;topicseen#new

-Mike

[G E]

Hello again!

I finished my four traps Saturday and am amazed at the transformation of my listening space.  I have been at this hobby for over 40 years and this is my first attempt at acoustically treating a room.  An amazing improvement in this room's acoustic signature from 4 traps and some unscientifically placed, raw OC703.  From my experience I'd say it's fair to say listening in an untreated space is analogous to sailing without a spinnaker or golf without the driver.  It is that big a deal.  

Thanks go to all those who directly or indirectly provided information on this and other forums.  Some of the theory was heavy going, but it is worth the effort.

Building these things was a bit trickier and involved than I thought it would be, but not ridiculous.  

BTW, I found an adhesive for fixing the OC703 panels to the wood frame and to each other - it is PL300 Foamboard Adhesive and the label specifically calls out wood and fiberglass panels as strata it bonds together.  I found it at HD.

I look forward to Phase 2 which is the construction of the absorption panels!

ge