upholstery fabric and bass traps?

[rcm]

In the new room I am putting together, I have a spot where I have the opportunity to put some bass trapping in a wall cavity (window frame) that will be behind some pretty heavy/thick/dense upholstery fabric. So the situation would be upholstery fabric -> 1 inch of space -> 4 inch bass traps -> 4 inch air gap -> wall.

I am assuming the bass frequencies would go right through the fabric. Any serious down sides to this?

[danbronson]

Depends on the fabric. They'll probably pass through or be absorbed, so either way...

[Glenn Kuras]

I am assuming the bass frequencies would go right through the fabric. Any serious down sides to this?

For the most part YES. If you want to make sure then do the blow test by holding it up to your mouth. All and all though the blow test is for upper frequencies.

Glenn

[weissguy]

I have some nice upholstery fabric that I think would go well with my existing bass traps. However, when I blow into it, air does not pass through easily.
Based on your comment, does that mean if I make 6" bass traps with this fabric, it will it still work to absorb lower frequencies, but reflect the mid-highs? And if I have a LOT of bass traps, would it be such a bad thing to have some of these mixed in with the others?

[Glenn Kuras]

Originally Posted by weissguy

I have some nice upholstery fabric that I think would go well with my existing bass traps. However, when I blow into it, air does not pass through easily.
Based on your comment, does that mean if I make 6" bass traps with this fabric, it will it still work to absorb lower frequencies, but reflect the mid-highs?

Yes it will reflect SOME of the mid-highs.

And if I have a LOT of bass traps, would it be such a bad thing to have some of these mixed in with the others?

You would need to test it to see but it might work pretty well that way.

Glenn