Studio retrofit advice - superchunks

[woodhall01]

Hi guys,

I am in the planning stages of building corner traps (superchunks) in my recording room. The room is far from ideal – almost a perfect cube at 3.2 x 3.25 x 2.7m. There are significant problems around 50-60Hz. I have some existing acoustic panels that I would like to re-use where appropriate (see pics). These helped significantly, but I am hoping the superchunks will be even more effective.

Usage of the room is limited to writing / mixing / vocal tracking electronic music. I mix at 80db. No isolation is needed, only internal acoustic treatment. My budget is around AU$1000 for materials.

The plan is to place two large superchunks on the front wall/side wall junctions 80x130x150cm(blue).

Additionally, all 4 ceiling junctions will have smaller 58x58x82cm superchunks (green).

Front Wall Length = 3200mm Construction = 200mm Concrete Block
Rear Wall Length = 3200mm Construction = 100mm Hebel Block
Side Walls Length = 3250m Construction = 100mm Hebel Block
Ceiling Height = 2700mm Construction: 26mm Plasterboard
Floor = 100mm Hebel Panels / Carpet

Room_sm.jpg

The main issues that I would like help with:

1) Rockwool... I have priced this using CSR Soundscreen R2.0. The density of this product is listed as 32.5kg/m3, this seems a little on the low side of ideal. Is there anything cheaper / better that I should think about using? As per profile, I am in Australia, so Australian products only please!

2) Wall/wall traps on front wall are... rather large Is this overkill? Law of dimishing returns, etc?

3) Too much absorption at mid-high frequencies? I am guessing that I will need to put some reflective material behind the fabric in the traps – would thick paper card / thin cardboard be ok? And how much of the superchunk surface area should have reflective material behind the fabric? 50%? 100%?

SuperchunkCrossSection_sm.jpg

ExistingPanels_sm.jpg

Any other comments / advice welcome also
Thanks!

[AVare]

What an earfull, pun intended. The 50-60 Hz problem is due to the 2 3.2 m wall spacings. Just about impossible to tame. The 32 kg/m3 is better for superchunks than denser material. If it was intuitive, it would not be acoustics! You have major modal problems. The amount of trapping is not excessive to ATTEMPT to control the problem. The room is small, and you have no absorption for flutter echoes, which will become audible if the traps are left full range. YEs some form of high frequency reflecting is good.

Andre

[woodhall01]

Thanks for the reply AVare, I've read some of your posts on GS

My interpretation of your reply is that it's almost a futile effort? So do I bother at all? I would expect that 4x more corner trapping would make a significant difference... I obviously don't expect the room to be flat, just '$1000 better'

To the aussies on the board, is there anything cheaper than the Soundscreen R2.0 (32kg/m3 and available in Australia) that will be as effective?

Lastly, is there going to be much of a perceptible difference between having the front traps at 30 degrees (as per diagram) or 45 degrees? The internal volume of each chunk would be the same, but the 30 degree chunks have slightly more surface area, and slightly less depth than the 45 degree. I prefer the 30 degree aesthetically, everything else being equal.

Thanks again for the reply. BTW, mods feel free to move this thread to Studio Design if it's more appropriate there.