# Super chunk bass traps..... all corners? 2 corners?



## Zeitgeist (Apr 4, 2009)

I know that there are a lot of recommendations on treating an entire room, such as first reflection points, front wall, rear wall, etc -- but I've found less information on bass traps. I've read at least one place "You can never have too many bass tarps"...

I'm building 1 7' tall "superchunk" 34" wide face bass trap (ala http://forum.studiotips.com/viewtopic.php?t=535) for one corner, but I was curious, ideally do you treat all 4 corners of the room?

As it stands now, I can't do triangle traps in the other 3 corners (one is a stair landing and one is near an equipment rack) -- but in a best case, do you want to treat them all? Or is it more important to focus on the walls rather than the corners? I believe that 2" works for broadband absorption, but 4" to 6" + is needed for LF absorption.


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## bpape (Sep 14, 2006)

Corners are an efficient place for bass control. That said, they are not a be-all, end-all solution to all of the bass issues. If you could post a sketch of your room, that would help.

Symmetry left to right in front of you is also very important. 

Bryan


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## Zeitgeist (Apr 4, 2009)

Haha, I get frustrated looking at acoustics threads with no pics, and I'm totally guilty of it.

Please excuse my very crude sketchup drawing. I need to invest some time in it.

The frustrating thing about the room is that neither the front nor the room is symmetrical, so that makes things difficult. The stairs in the left take up a corner, and the closet (that has a water meter in it, otherwise I would have demoed it) in the right.


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## bpape (Sep 14, 2006)

Maybe we can get a bit createive...

How tall are the sub cabinets?

How much space between left wall and equipment rack?

Can we steal a little bit of wall space in the stair landing (don't know where things go in terms of stairs).

How tall is the ceiling? Can we do soffits? Still corners but lots of room and no floorspace taken up.

Just scheming.

Bryan


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## Zeitgeist (Apr 4, 2009)

bpape said:


> How tall are the sub cabinets?
> How much space between left wall and equipment rack?
> Can we steal a little bit of wall space in the stair landing (don't know where things go in terms of stairs).
> How tall is the ceiling? Can we do soffits? Still corners but lots of room and no floorspace taken up.


Sub cabs are 4', and that leaves 3' above it. Right now the screen is not AT, there is about 3' below the screen where the subs/speakers are with GOM fabric.

Right now I have some R13 on the back wall, which helps deaden the airspace that's empty - behind the screen. I put in R13 on the back wall behind the screen before I knew anything about fiberglass.

I'll have to measure the landing -- wall space would work. Right now I have 2 movie posters which I could easily move. What about two 2'x4' 4in thick OC703 panels on the wall near that corner, would that help at all? As an alternative to a triangular trap?

Ceiling is 7'. By soffit, do you mean something similar to this? http://www.asc-home-theater.com/products-soffit2.htm I've seen some soffits, that are only wood, with lighting above.. .but I'm not sure I understand how those benefit the room acoustically?


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## bpape (Sep 14, 2006)

In the corners, 4" flat on the wall is better than nothing.

If the upper portion of the front wall (not the screen portion) is drywall, that should be removed and made just cloth and then we do both corners back there.

Yes on the soffits. What you do is just frame it, fill with insulation, and then cover in cloth (no drywall). Becomes one huge broadband bass absorber.

Bryan


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## Zeitgeist (Apr 4, 2009)

Hmm. You've given me some food for thought. I'm going to go to an AT screen at some point too, so then that would open things up a little more too.

I like the soffits idea, but I think the WAF would probably kill it..

At some point I know I'll move... and a priority for me is a room more suited for theater.

Is 2" good for first reflections?

I seem to recall someone saying that 1" is somewhat ineffective except for covering large areas for the purpose of broadband absorption.

Thanks for your help


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## bpape (Sep 14, 2006)

1" will tend to skew the amount of high frequency vs mid/low frequency absorption if too much is done. 2" is usually OK unless you have the speakers really close to a side wall, then the first one you'd want to be more like 4"

If WAF is an issue, you can make the soffits say 12" wide but only 6" tall so they're not so obtrusive yet can still be very effective.

Bryan


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## Zeitgeist (Apr 4, 2009)

Cool, thanks for your help Bryan!


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