Bass traps down the side of cupboards.

[Elmutcho]

Hi there,
I am wanting to pick some brains about designing some stealth bass traps.
I have a music room that I am trying to make as acoustically good as possible but it is on display in the house and the wife is very firm about aesthetics.
I have a wall, mostly out of sight that I am planning to put some built in cupboards in to store my guitar cases (because they're ugly) and keep the room tidy. I was thinking of using Ikea wardrobes and customising a little.

I was then thinking that I may have an opportunity here to put in some stealth bass traps and a back wall treatment.
I was wondering if I could build the cupboards out from the wall and put a bass trap down the side.

So the question is how would this work, how wide would the face of the trap need to be and how deep the material. And then if it sounds like a good idea, what kind of material could i build a trap out of for this size?

Here's a rough mock up to illustrate, thinking about traps where the pink/red areas are. Room is 250cm high, 400cm wide, 6m long.

thanks for any help

 

[Snoopy]

Look at the size and shape of professional bass traps and you get a idea. If the traps are thin you will only absorb high frequencies.

 

[Bjorn]

Stealth and small bass traps? Doesn't exist due to the wavelength of low frequencies. Not even large enough to absorb mids.

 

[Elmutcho]

The dimensions are flexible, that’s the point. What I mean, is I placed say something the equivalent of GIK acoustics Soffit bass traps down the side of the cupboards. They are 42cm, but I’m asking what the minimum size? If I had a 30cm gap either side floor to ceiling filled with absorbing material is that wide enough?? Stealth as they are out of line of sight and I could make them white to blend with the walls??

 

[Geert]

The size of that kind of traps determines the efficiency at very low frequencies. The efficiency of the 42cm GIK acoustics Soffit bass traps already drops substantialy below 90Hz. That means that smaller ones actually are not bass traps anymore. Especially if you only use absorbant material and no membrane (see the difference that makes on the GIK website). So the 42cm already is a minimum (and without the membrane not even, they won't have much impact on the major room modes).

 

[Bjorn]

The total dimension matters. You don't have the space for something that works well in the lows it seems.

 

[Elmutcho]

This is just an early planning stage, maybe I haven’t been clear, I’ve just got a bare wall at the moment. I’d like two cupboard for storage, and wondering what I can do around them. What happens if I stack something like 2 GIK bass traps in either corner, next to the cupboards, will that work if only on surface is facing into the room?

 

[Geert]

This is just an early planning stage, maybe I haven’t been clear, I’ve just got a bare wall at the moment. I’d like two cupboard for storage, and wondering what I can do around them. What happens if I stack something like 2 GIK bass traps in either corner, next to the cupboards, will that work if only on surface is facing into the room?

They will loose efficiency. Efficiency that was already not to high to begin with.

 

[ozzy9832001]

This is just an early planning stage, maybe I haven’t been clear, I’ve just got a bare wall at the moment. I’d like two cupboard for storage, and wondering what I can do around them. What happens if I stack something like 2 GIK bass traps in either corner, next to the cupboards, will that work if only on surface is facing into the room?

Corner traps would probably work in this instance, since they are designed to only have the 1 face facing into the room (triangle design, not baffle).

In order for that to work correctly, this would have to be either the front or rear wall. Side wall wouldn't work as it would unequally absorb and cause imaging issues.

Depending on where your MLP is from the speakers and which boundaries are closest would really dictate which is better.

Taste obviously dictates, but I think, if done correctly, acoustic paneling can actually be very well done and looks great. You can even get companies to print pictures and designs on them to spruce them up.

As far as depth is concerned, in order to really handle the really low end (80hz and below), the traps probably need to be a good 12" thick, if not 16" and a combo of high and low density absorption.

 

[dasdoing]

do it inside. just straddle the corners. also there is a corner at the bottom, too

 

[Bjorn]

This is just an early planning stage, maybe I haven’t been clear, I’ve just got a bare wall at the moment. I’d like two cupboard for storage, and wondering what I can do around them. What happens if I stack something like 2 GIK bass traps in either corner, next to the cupboards, will that work if only on surface is facing into the room?

Without mentioning the total dimension no can answer this. But based on what you're showing in the picture you'll basically only get som high frequency absorption.

To absorb lows with porous material requires large dimensions in both width height and depth. That's physics.

 

[Bjorn]

Oh, let me add one more thing. The GIK Tri-Trap or Soffit aren't really serious bass traps. They are way too small to be effective below 100 Hz. The measurement techniqu is bogus.

 

[sarumbear]

This is just an early planning stage, maybe I haven’t been clear, I’ve just got a bare wall at the moment. I’d like two cupboard for storage, and wondering what I can do around them. What happens if I stack something like 2 GIK bass traps in either corner, next to the cupboards, will that work if only on surface is facing into the room?

Technically, you can integrate a membrane basstraps or Helmholtz resonators to your cupboards by leaving enough volume behind them.

Contrary to what @Bjorn said, you do have a large volume to play with, which is enough to affect bass down to around 40-50Hz. Mind you, I’m talking theoretically. Nothing ready made will work for you. You need a custom solution.

 

[Kervel]

An alternative is to place some subwoofers below the cupboards; at least 2; but 4 are better No problem if they are fairly small. Then you can cover the woofers with some sort of nice looking fabric / curtain or thin wood/planks. For this route to work, the subs need proper DSP (Dirac, multi-sub etc.) to get smooth bass.

 

[sarumbear]

An alternative is to place some subwoofers below the cupboards; at least 2; but 4 are better No problem if they are fairly small. Then you can cover the woofers with some sort of nice looking fabric / curtain or thin wood/planks. For this route to work, the subs need proper DSP (Dirac, multi-sub etc.) to get smooth bass.

In other words a SBA, Single Bass Array, like this.

 

[ErVikingo]

I did something similar in my old room. I built a fake wall with enough space to fit very large ASC tube traps in the corners and diffusers in between (note, the projection screen was a porous Stewart and had diffusers behind floor to ceiling). Kind of did the same on the side walls; used a product that allowed to put fabric on the walls and provided 2.5" of space. I attached sections of Owens C panels. Then I made "tables" to hide the subwoofers (square boxes on the sides under the guitars). It worked out pretty good and had a very high WAF. Dam that was some time ago as documented by my old Compaq!

 

[neRok]

Bass array seems like a great idea! Actually it would be a double bass array, because they are on the back wall, and they would be use to "cancel" the bass coming from the speakers. They could also do just the "sub bass", so maybe 1.5x bass array. Or subs at the front too, and then it is double bass array.

Alternatively, if your room has the length, I reckon you could bring the cupboard forward ~300mm and fill the void behind with light insulation. Then it will be quite absorbative to bass waves, and it would be "out of sight". By leaving the sides and the middle of the cupboard structure open, the waves should get enough "access"?

 

[Elmutcho]

Thank you, not sure I have the funds for the bass array.. but something I will think about.

Alternatively, if your room has the length, I reckon you could bring the cupboard forward ~300mm and fill the void behind with light insulation. Then it will be quite absorbative to bass waves, and it would be "out of sight". By leaving the sides and the middle of the cupboard structure open, the waves should get enough "access"?

Unfortunately the cupboards needs to be structural, they're going to contain the multiple hard guitar cases.

To try to demonstrate a little more, this is more what i'm envisioning? If say I put 4x the 17x46.5 inch soffit bass traps either side, leaving 20cm air gap behind. Plus Something like the 6" SlatFusors in the middle? even floor to ceiling.

 

[neRok]

Thank you, not sure I have the funds for the bass array.. but something I will think about.


Unfortunately the cupboards needs to be structural, they're going to contain the multiple hard guitar cases.

To try to demonstrate a little more, this is more what i'm envisioning? If say I put 4x the 17x46.5 inch soffit bass traps either side, leaving 20cm air gap behind. Plus Something like the 6" SlatFusors in the middle? even floor to ceiling.

View attachment 318485

Surface area comes in to it as well. You've covered 20% of the wall with bass trap there.

The guy in the following link sells products and has videos on youtube (and people call him a bit of a conman, so think what you want), but I think he is right when he says stuff like "Most home studios need at least 60% of each wall treated in order to have the desired audible impact."

"Structurally" you should be able to build cupboards that stand up on their own. You can always brace the tops back to the walls for stability.

 

[Elmutcho]

I realise it is not going to be perfect or full range or whatever you are holding to gold standard. What I’m trying to ask is if I am limited with what I can do, will that make some difference and where can I tweak to make the most improvements. 20% coverage is surely better than none.. I’m not getting 60% of the wall covered in treatment but I can certainly look at what goes in between the cupboards as well. So where is best to focus and in what design.