Building Bass Traps, a chronology.

I wonder how easy roxul rockboard 60 is to cut? The superchunks I'm thinking about that'd fit my room nice are looking like a lot of work!
 
Finally got this pic up - this is a 18" x 48" x 4" 45 degree angle corner trap - I think it works better than a superchunk and it's a lot more portable. Hangs with 2 drywall screws!


corner_panel.jpg
 
Works better? Sorry but I will have to interject here. A 'superchunk' type of trap will always have a better capability of 'trapping' low end frequencies than a small 4" panel straddling a portion of the corner like you have there. Yes your build is effective, but 'better' is not the correct term. Better in the particular case of aesthetics maybe. Not better as far as performance is concerned.

Actually, corner traps as far as I have read, are most efficient with fluffy type insulation held in an enclosure from floor to ceiling. I can only guess that cost is the biggest issue there.
 
I like it a lot! But apparently the definition of 'better' is open for debate. Arcadeko's corner panel with the 45º angles is more efficient per cu ft of rockwool/oc70x than a superchunk. The material in the very inner corner absorbs a lot less than the material in the deko trap that's a foot away from the corner. But that little inside corner DOES help a little, so technically the superchunk with the same front face dimensions will perform better. But you might be able to make 3 deko 45º corner traps with the same material as 2 superchunks, and deko's 3 traps will definitely absorb more. Deko's traps take the most inefficient material of a superchunk and move it farther out to a location where it can do more good.

To optimize that equation is the question.. given 1 case of oc703 or whatever. 4x2x1'=8 cu ft - what dimensions to make the traps to use all the material and get the most absorption. I dont do math this late but it's something to think about.
 
Good point. :D
suprstar said:
I like it a lot! But apparently the definition of 'better' is open for debate. Arcadeko's corner panel with the 45º angles is more efficient per cu ft of rockwool/oc70x than a superchunk. The material in the very inner corner absorbs a lot less than the material in the deko trap that's a foot away from the corner. But that little inside corner DOES help a little, so technically the superchunk with the same front face dimensions will perform better. But you might be able to make 3 deko 45º corner traps with the same material as 2 superchunks, and deko's 3 traps will definitely absorb more. Deko's traps take the most inefficient material of a superchunk and move it farther out to a location where it can do more good.

To optimize that equation is the question.. given 1 case of oc703 or whatever. 4x2x1'=8 cu ft - what dimensions to make the traps to use all the material and get the most absorption. I dont do math this late but it's something to think about.
Click to expand...
 
Yeah I did some reading on panel versus superchunk. I am by no means an expert, but from what I understood, the empty space in the corner behind the panel actually helps the panel work more efficiently or something. :) And yeah it's about the most efficient use of material, I can cover an entire 8 foot corner with 3 sheets of insulation. A superchunk trap would only have a 16" face using 3 panels floor to ceiling (each is 32" tall triangle-cut and stacked), the panels on the other hand have an 18" face.

While the panels are only 4" thick in the middle, the superchunk is a fuller 6" thick, but remember thats ONLY in the direct center, the triangle loses its thickness quickly - 2 inches from center you are already down to 4.5 inches thick, another two inches and you are under 4"! -0 the panels give you 4" of thickness in a 12" width...

Anyway - from a material standpoint, taking 3 panels of 2x4 insulation and using them for a corner, you get more face area with panels. So that is why I think they are better :) they are also a hell of a lot easier to build and move around!

I am going to investigate the recommended density, if the light fluffy stuff works better in the corners then I will get that. I wonder if it works as well in a corner panel as opposed to a superchunk?
 
Yeah I did some reading on panel versus superchunk. I am by no means an expert, but from what I understood, the empty space in the corner behind the panel actually helps the panel work more efficiently or something. :) And yeah it's about the most efficient use of material, I can cover an entire 8 foot corner with 3 sheets of insulation. A superchunk trap would only have a 16" face using 3 panels floor to ceiling (each is 32" tall triangle-cut and stacked), the panels on the other hand have an 18" face.

While the panels are only 4" thick in the middle, the superchunk is a fuller 6" thick, but remember thats ONLY in the direct center, the triangle loses its thickness quickly - 2 inches from center you are already down to 4.5 inches thick, another two inches and you are under 4"! -0 the panels give you 4" of thickness in a 12" width...

Anyway - from a material standpoint, taking 3 panels of 2x4 insulation and using them for a corner, you get more face area with panels. So that is why I think they are better :) they are also a hell of a lot easier to build and move around!

I am going to investigate the recommended density, if the light fluffy stuff works better in the corners then I will get that. I wonder if it works as well in a corner panel as opposed to a superchunk?
 
Panel v. superchunk: with a panel you can span more of the corner with the same amount of material. With superchunks you get a deeper amount of absorption and better performance. The experts (ie. not me) say that if money is tight then a panel will give better value for money. The norm being either 600mm/24" wide panels, floor to ceiling, or 600mm/24" or even better 850mm/34" superchunks.

Air gap: with bass traps, ie, traps in corners, you want the traps right up against the wall. With broadband traps, ie. traps on walls and ceiling, will benefit from having as a gap behind them the same depth as the trap itself. Normally this would be 100mm/4" gap for a 100mm/4" deep trap.

Density: for superchunks, which have a greater depth, ordinary cheap insulation is better. For panel bass traps and broadband traps where depth is much shallower then higher density (6pcf) insulation performs better. In the US, Owens Corning 705 is the preferred dense absorption material. There are Roxul Safe 'n' Sound and Knauf Ecosse equivalents.
 
Panel v. superchunk: with a panel you can span more of the corner with the same amount of material. With superchunks you get a deeper amount of absorption and better performance. The experts (ie. not me) say that if money is tight then a panel will give better value for money. The norm being either 600mm/24" wide panels, floor to ceiling, or 600mm/24" or even better 850mm/34" superchunks.

Air gap: with bass traps, ie, traps in corners, you want the traps right up against the wall. With broadband traps, ie. traps on walls and ceiling, will benefit from having as a gap behind them the same depth as the trap itself. Normally this would be 100mm/4" gap for a 100mm/4" deep trap.

Density: for superchunks, which have a greater depth, ordinary cheap insulation is better. For panel bass traps and broadband traps where depth is much shallower then higher density (6pcf) insulation performs better. In the US, Owens Corning 705 is the preferred dense absorption material. There are Roxul Safe 'n' Sound and Knauf Ecosse equivalents.
 
Capriccio said:
Density: for superchunks, which have a greater depth, ordinary cheap insulation is better. For panel bass traps and broadband traps where depth is much shallower then higher density (6pcf) insulation performs better. In the US, Owens Corning 705 is the preferred dense absorption material. There are Roxul Safe 'n' Sound and Knauf Ecosse equivalents.
Click to expand...

IDK about that. 'Better' meaning better absorption per dollar, ok I could beleive that. Unless someone proves to me otherwise, I think a superchunk loaded with oc705 will outperform a superchunk of the same dimension made of pink fluff. It's just that the 705 one would cost 300% of the pink one, while only performing maybe 20% better.
 
Who has the capacity to do an actual corner recording? Build two corner absorbers, and test them and SPL them? Maybe get a response curve?

If my guitarist and I can get good enough test software before we do our room. I'll build a 2' wide floor to ceiling absorber 4" thick rigid filler, and then a superchunk using 16" wide loose filler, and see what results we get. Use my SPL meter too. I'd make sure to track dollar for dollar all material costs, and photos of how they're constructed. Whichever results we like better, we'll build the rest to match.


EDIT: Is there any kind of benefit to building a superchunk with back walls? Or should the front and the two back sides be fabric and breathe?
 
Bryan316 said:
Who has the capacity to do an actual corner recording? Build two corner absorbers, and test them and SPL them?
Click to expand...

Anyone can. Broadband traps can be used for the first test, panel traps, and then the superchunks used for the second test. With no other traps in the room for either test you will have comparable data. Rather than 'SPL them' as SPL meters give a single reading covering the whole frequency spectrum, acoustics measurement software should be used. As most studio owners have a microphone and a computer and one working monitor, once a program such as REW or Fuzz measure has been installed (and a bit of learning done), anyone can do these tests.

Bryan316 said:
Is there any kind of benefit to building a superchunk with back walls?
Click to expand...

Superchunk (filled triangular) traps should not have a gap behind them so there is no benefit to them having the two hidden sides backed unless it helps provide stability for the frame, if you make a frame to put them in.

Bryan316 said:
Or should the front and the two back sides be fabric and breathe?
Click to expand...

There doesn't seem to be a definitive answer. The starting position is to have a breathable fabric. If you use a non-breathable membrane, such as paper or foil, then the higher frequencies will be reflected, not absorbed. Some who need some reflection use slats so that there is partial reflection and partial absorption. So, you see, when we get down to the specifics of each studio and its sound, the final tweaks are specific to each room.
 
Roxul Safe and Sound is 40kg/m3:

Density:
2.5 lbs/ft3 40 kg/m3

Roxul Safe'n'Sound

Shop Roxul 12-Pack 47"L x 15-1/4"W x 3"D 0-R Stone Wool Insulation Batts at Lowes.com


But I can't seem to find the density for Owens Corning EcoTouch R-19 Unfaced

EcoTouch R-19 Unfaced 6-1/4 in. x 15 in. x 93 in. Batts in Bag Insulation-BU40 at The Home Depot

It looks like over 11" thick and lighter is better, so maybe I would make superchunks instead of corner panels. Or big oblong boxes like the soffit traps: GIK Soffit Bass Trap - Gearslutz.com

I would be able to get the OC sooner cause I can order it from HD with my CC

Anyone know the density of that stuff?
 
Not a jack man. A good question. Basically it is a design where layers of dense insulation is stacked, in horizontal slabs, vertically in a corner, completely filling the corner diagonally. Did that make sense?
 
jimmys69 said:
Not a jack man. A good question. Basically it is a design where layers of dense insulation is stacked, in horizontal slabs, vertically in a corner, completely filling the corner diagonally. Did that make sense?
Click to expand...

Ok, so i am working on my own stuff, what type of insulation is used?
 
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