Corner Traps vs. Rectangular Traps Straddling Corners

[aclarson]

Hello, I was just wondering if there's any difference in effectiveness between a corner trap (one with the sides angles to fit sleekly in the corner) and just using a standard rectangular trap straddling the corners. I know the superchunks are best, but I'm trying to figure out which is better for the more cost-effective types.

Under the presumption that any visible sides on either style would be exposed insulation for maximum efficiency, is there a loss in effectiveness with the corner trap?

I'd prefer to make them corner traps for aesthetic value primarily, but if I take much of a hit on absorption, I'll just go with the standard rectangles. Anyone know? Thanks in advance,

-Aaron-

[Glenn Kuras]

Generally 4" panel straddling the corner is your best BANG for the BUCK. But things like your Tri Trap filling the full corner take up far less room and work A LOT better below 50hz

Glenn

[aclarson]

Thanks for the response Glenn, sorry, I think I was a little unclear, I meant the types that are like a normal 4" thick panel trap except they have beveled edges to fit in the corners nicely (I considered the filled-in style like your Tritraps but ultimately decided on the straddling panel for cost effectiveness.)

I'm wondering about the difference between these beveled traps and a normal rectangular panel trap where the sides sit off the wall. Is this a cosmetic difference only, or does the additional exposed fiberglass provide any additional absoption? I'd like to do this for the looks aspect, but I don't want to sacrifice any absorption for the sake of appearance. Does beveling the side and having it fit flat against the two surfaces reduce the total amount of absorption?

Thanks,

-Aaron-

[timmcallister]

fwiw

i tried 4" panels straddling the corners for a few years. yes, they helped but...

Placing absorption throughout the room and handling the > 100hz frequencies is pretty straight forward.

Handling the < 100Hz freqs takes some effort.

When I built some super chunks it took the room into a whole new league (very measurable) in the low end. I will never go back. It's very cheap and easy to do yourself (though the production units will probably look better). I can't imagine trying to do work without them.

ymmv, imho, fwiw, etc

have fun

[aclarson]

Originally Posted by timmcallister

It's very cheap and easy to do yourself

Hmmm...interesting. Did you make them our of rigid fiberglass? Or something more inexpensive? Thanks man,

-Aaron-

[dredbird]

Originally Posted by aclarson

Hmmm...interesting. Did you make them our of rigid fiberglass? Or something more inexpensive? Thanks man,

-Aaron-

I just made two corner chunk style traps using 4" rockwool, (Roxul Safe).

It took three panels each to make 2- 24X17X17 8' tall traps. At 3 panels per bundle, it took 2 bundles which out here cost me $44.

[parissound]

How did you get 8' out of 3 panels?
I am addding them up and I come up with only 48"per 3 panels.
How many triangle panels you get out of one panel?

[Glenn Kuras]

Originally Posted by aclarson

Thanks for the response Glenn, sorry, I think I was a little unclear, I meant the types that are like a normal 4" thick panel trap except they have beveled edges to fit in the corners nicely (I considered the filled-in style like your Tritraps but ultimately decided on the straddling panel for cost effectiveness.)

I'm wondering about the difference between these beveled traps and a normal rectangular panel trap where the sides sit off the wall. Is this a cosmetic difference only, or does the additional exposed fiberglass provide any additional absoption? I'd like to do this for the looks aspect, but I don't want to sacrifice any absorption for the sake of appearance. Does beveling the side and having it fit flat against the two surfaces reduce the total amount of absorption?

Thanks,

-Aaron-

If you cut away at the side of a panel then you are cutting away absorption. It really is that plan and simple. I think it would still work but you are lessening the distance from the lead edge to the back corner so in theory it is not going to work as well. I myself would not do it. Ether straddle a full 4" (or 6") panel across the corner or better yet, as timmcallister said, fill the full corner.

Glenn

[dredbird]

Originally Posted by parissound

How did you get 8' out of 3 panels?
I am addding them up and I come up with only 48"per 3 panels.
How many triangle panels you get out of one panel?

8 triangles per panel X 4" =32" X 3 = 96" (8')

What's funny is I bought 4 bundles for the job

[parissound]

Sounds great, Thanks.

[aclarson]

So, I ordered, (18) 2' x 4' x 4" pieces of Rockboard to go in this room:



The way I'm thinking I'll do it now is to do the superchunk thing in the four main wall-wall corners, which will take up 12 pieces, and have 6 traps left over for wall-ceiling corners (I might save one for a portable vocal booth type thing, too).

Problem is, two of the corners won't fit the 'chunks' if they're made in the usual isosceles right triangle size (2' x 2' cut into 4 pieces with two 17" sides and one 24" side). This is because one of the 17" sides doesn't fit in the corner by the front door in the pic. The space between the door frame and the wall is just over a foot.

What I was thinking I could do is take a 1' x 2' piece and cut it corner to corner to make a two pieces with one 12" side, one 24" side, and one 26" side. Then I could put the 12" side between the door and the wall and put the 26" side on the wall where there is plenty of space. The amount exposed is still the same, the minimum depth from insulation to corner is the same (12"), and the amount of material used is the same. It just has to be used in pairs (which I was doing anyway).

My only questions are:
Does this affect the effectiveness of the 'chunks'?
If so, would I still be better off than using a standard 4" trap at an uneven angle?

Thanks,

-Aaron-

[timmcallister]

Originally Posted by aclarson

Hmmm...interesting. Did you make them our of rigid fiberglass? Or something more inexpensive? Thanks man,

-Aaron-

I made all "panels" out of 703. The superchunks are rockwool (way cheaper).

I can't stress what a HUGE difference the super chunks made to balancing out low end in the room. I posted all my charts here at GS a few years ago. It was impressive on the graphs, but even more impressive being able to hear such a balanced low end.

While cheap, I made up for it in labor and frankly, they look good, but not great like Glenn's :-)

[jwl]

Beveling the edges of a trap should be done purely for cosmetic reasons. Glenn is right, you are cutting away absorption.

For example, our MondoTrap vs. our Corner MondoTrap are the same design except the beveled edges. The regular MondoTrap performs a bit better, but the beveled edge makes the Corner MondoTrap appear to only be 1" thick when installed.

So it's a question of aesthetics vs. peak performance.

[bpape]

Originally Posted by aclarson

So, I ordered, (18) 2' x 4' x 4" pieces of Rockboard to go in this room:



The way I'm thinking I'll do it now is to do the superchunk thing in the four main wall-wall corners, which will take up 12 pieces, and have 6 traps left over for wall-ceiling corners (I might save one for a portable vocal booth type thing, too).

Problem is, two of the corners won't fit the 'chunks' if they're made in the usual isosceles right triangle size (2' x 2' cut into 4 pieces with two 17" sides and one 24" side). This is because one of the 17" sides doesn't fit in the corner by the front door in the pic. The space between the door frame and the wall is just over a foot.

What I was thinking I could do is take a 1' x 2' piece and cut it corner to corner to make a two pieces with one 12" side, one 24" side, and one 26" side. Then I could put the 12" side between the door and the wall and put the 26" side on the wall where there is plenty of space. The amount exposed is still the same, the minimum depth from insulation to corner is the same (12"), and the amount of material used is the same. It just has to be used in pairs (which I was doing anyway).

My only questions are:
Does this affect the effectiveness of the 'chunks'?
If so, would I still be better off than using a standard 4" trap at an uneven angle?

Thanks,

-Aaron-

In the corners you don't have space - just cut the triangles in half again. That'll give you 12x12x17 triangles that'll fit nicely in the space you have to work with.

Bryan

[aclarson]

Originally Posted by bpape

In the corners you don't have space - just cut the triangles in half again. That'll give you 12x12x17 triangles that'll fit nicely in the space you have to work with.

Bryan

Ahhhhhhhhhh....brilliant simplicity. Why didn't I think of that? You could call them Mini-Chunks.

I'm curious though, this would actually be less material than two 2'x4' normal 4" thick traps at an angle. Would the performance still be superior to those?

Here's an even more bizarre question (somewhat rhetorical): If you put a normal trap in front of a 'chunk', would that noticeably add to the effectiveness? Would it need to be right up against the chunk? Would an air gap between the two have a positive/negative/no effect?

Thanks again everybody for the excellent advice, you guys are awesome!

[jwl]

I doubt if a "minichunk" would outperform a 2' wide panel that is at least 4" thick. Bass trapping is also about surface area and coverage area in the room. Though without seeing the 2 approaches tested (at the same time by the same facility) it's hard to tell.

Basically you reach a point of diminishing returns. 4" panels straddling the corner give about 80-90% of the performance of superchunks, at a much lower material cost. In general, you are better off using that material to cover all 12 corners of the room. If you want to superchunk all 12 corners, so much the better.

Spacing panels out from the wall gives increased overall absorption, and more absorption at the lowest frequencies. So theoretically, the thicker the material, and the further spacing from the wall, the better. But once you get 4" thick straddling a corner or 4" out from the wall, you are getting close to the top of that curve.

[Glenn Kuras]

Basically you reach a point of diminishing returns. 4" panels straddling the corner give about 80-90% of the performance of superchunks, at a much lower material cost. In general, you are better off using that material to cover all 12 corners of the room. If you want to superchunk all 12 corners, so much the better.

Just to clarify, at 50hz filling the corner is twice as much absorption. I will agree though that 4" is the best bang for the buck "over all" but every room is different and every room needs different treatment.

Glenn

[parissound]

Originally Posted by dredbird

8 triangles per panel X 4" =32" X 3 = 96" (8')

What's funny is I bought 4 bundles for the job

I just bought 3 bundles (9pcs) of 4" mineral wool and cut them down like you said but still did not have enough to complete up to 8'.

I was only able to do 1 corner and 1/2 of the other.

I think you miscaculated becuase I came real short, looks good though. I will pick up some more tomorrow.

Thanks

[RCM - Ronan]

When building superchunks, is there a point of diminishing return when it comes to size?

For instance if your wedges were 24x24x34, would that be roughly twice as effective for treating low frequencies as the 17x17x24, or does effectiveness start to roll off at some point. Basically how much better off are you getting 4 wedges a panel instead of 8?

[avare]

Originally Posted by rcm

When building superchunks, is there a point of diminishing return when it comes to size?

Diminishing starts when you use something more than a roll of toilet paper. The best value in a microphone is what dollar stores sell. If you are working with money, do the calculations to determine how much absorption you need.

Andre

[Glenn Kuras]

Originally Posted by rcm

When building superchunks, is there a point of diminishing return when it comes to size?

For instance if your wedges were 24x24x34, would that be roughly twice as effective for treating low frequencies as the 17x17x24, or does effectiveness start to roll off at some point. Basically how much better off are you getting 4 wedges a panel instead of 8?

I am not aware of any lab testing of something bigger then 17x17x24 but I can tell you that 17x17x24 works darn well and can say with almost 100% confidence that twice as many 17x17x24 in a room will work more then twice as good, then half of the amount of something twice the size. My head hurts from that last sentence. Did I say that right?

Glenn

[RCM - Ronan]

Originally Posted by avare

Diminishing starts when you use something more than a roll of toilet paper. The best value in a microphone is what dollar stores sell. If you are working with money, do the calculations to determine how much absorption you need.

Andre

Sorry, Andre, but I have no idea what you are trying to tell me here.

I own one of the dollar store mics. I chose the red one.

[RCM - Ronan]

Originally Posted by Glenn Kuras

I am not aware of any lab testing of something bigger then 17x17x24 but I can tell you that 17x17x24 works darn well and can say with almost 100% confidence that twice as many 17x17x24 in a room will work more then twice as good, then half of the amount of something twice the size. My head hurts from that last sentence. Did I say that right?

Thanks Glen, I think that points me in the right direction.

[avare]

Originally Posted by rcm

Sorry, Andre, but I have no idea what you are trying to tell me here.

I own one of the dollar store mics. I chose the red one.

An attempt at dry humour. The dollar store microphone works as a microphone. Anything more expensive gets into diminishing returns.

Humorously,
Andre

[desotoslo]

Originally Posted by rcm

Sorry, Andre, but I have no idea what you are trying to tell me here.

I own one of the dollar store mics. I chose the red one.

u r a rockstar

[AdamWathan]

Originally Posted by parissound

I just bought 3 bundles (9pcs) of 4" mineral wool and cut them down like you said but still did not have enough to complete up to 8'.

I was only able to do 1 corner and 1/2 of the other.

I think you miscaculated becuase I came real short, looks good though. I will pick up some more tomorrow.

Thanks

You must've only cut each panel into 4 triangles instead of 8...

[andycraig]

Hi - I hope you don't mind me jumping in on this thread but I'm considering the option of filled corners instead of straddling the corners and I thought this was the most relevant place to ask my question. The reason for opting for triangles is I'm tight for space and straddling is going to take up a lot more rrom.

My question is, would corners filled with triangles at 300x300x420mm (11.75x11.75x16.5") be effective for low end absorbtion? I see the sizes quoted in this thread are using larger triangles but my dimensions are based on using 1200x600mm slabs of insulation (8 triangles).

My room dimensions were posted in this thread and so far I've constructed 4 traps for the walls (1200x600x100mm). Also, slightly off-topic sorry, but these 4 traps will currently sit 25mm off the wall - is that gap better than nothing or would they be better off flush to the wall if a bigger gap isn't possible?

Thanks,

Andy

[Glenn Kuras]

My question is, would corners filled with triangles at 300x300x420mm (11.75x11.75x16.5") be effective for low end absorbtion? I see the sizes quoted in this thread are using larger triangles but my dimensions are based on using 1200x600mm slabs of insulation (8 triangles).

It will work, but just keep in mind that it will not work as well and if that is the best you can do then GO FOR IT. But without lab testing there really is no way to tell you how affective it will be.

My room dimensions were posted in this thread and so far I've constructed 4 traps for the walls (1200x600x100mm). Also, slightly off-topic sorry, but these 4 traps will currently sit 25mm off the wall - is that gap better than nothing or would they be better off flush to the wall if a bigger gap isn't possible?

Once again hard to tell without testing, but I would think you would be fine if you had to space it. It may help a little but I doubt it is going to a HUGE difference one way or another.

Glenn

[andrebrito]

Tri Trap filling the full corner

What kind of bass trap is this ? Filling the entire corner wall with rockwool ? How come this achieves good absorption below 50 Hz if there's no air resonance or membrane involved ?

[Glenn Kuras]

Originally Posted by andrebrito

What kind of bass trap is this ? Filling the entire corner wall with rockwool ? How come this achieves good absorption below 50 Hz if there's no air resonance or membrane involved ?

Well the whole corner is a solid piece of rockwool!!!

Glenn