My control room

  • Thread starter Thread starter pandamonk
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cincy_kid said:
1) Yea, Realtraps are quite the product, but out of my budget and overkill for me in my small space atm.

2) Oh, so the entire height of the wall in the corner? Interesting...I was thinking of putting fabric around the triangles and making them look similar to this shape

3) I have no space to straddle (small space as it is)

4) I have this extra 703 I will use and try your stacking method.

Well, it's not my method. But 2 and 3 take up basically the same amount of space.
 
apl said:
I'm having trouble finding something to link to, but if you go to Ethan's acoustics page you can see how fast the absorption coeffecients drop off when you get beyond their useable range. And, frankly, I don't believe 4" of fiberglass is going to do much at 125Hz and I am suspricious of the specifications.
I've read through that page a couple of times before. On a very quick skim i just had there i didn't see any coefficients that went below 125Hz. It's actually not 4" rigid fiberglass, but 3.5" natural cotton fiber insulation. BondedLogic Ultratouch. I understand that you don't trust the spcs, but they are all we have to go on before we buy the product really, aren't they. Either that or word of mouth. But this seems like a relatively new product, so most probably haven't even heard of it yet, nevermind used it and tested it.
 
pandamonk said:
I understand that you don't trust the spcs, but they are all we have to go on before we buy the product really, aren't they. Either that or word of mouth. But this seems like a relatively new product, so most probably haven't even heard of it yet, nevermind used it and tested it.

Or physics.
 
pandamonk said:
That too, do you know how to calculate it?

Absorptive acoustic materials work by converting the air molecules' kinetic energy to heat. As the wave is reflected from the wall, the velocity at the wall is zero, and the maximum velocity is at the 1/4 wavelength. For 125 Hz, the 1/4 wavelength is around 24" from the wall. So when the acoustics experts build anechoic chambers, they use 24" thick treatment and rate it down to 125 Hz. They're being extemely precise about it, though. That said, there is so little molecular movement of a 125 Hz wave 4" from the wall that no absorber can do much about it.
 
How can these companies get away with lying though? There must be some truth in what they are saying or they would be sued like nothing else.
 
pandamonk said:
How can these companies get away with lying though? There must be some truth in what they are saying or they would be sued like nothing else.

Testing acoustic materials is tricky business and it's not very hard to get the numbers you want.
 
Surely they'd have to do it right or they could get sued for false advertising
 
pandamonk said:
I don't get you. And yeh i know they are

I used to be a member of the Acoustical Society of America. The funniest part of the journal was the new patents section because a lot of the claims were just silly.

Those specifications are often stretching things a bit. You can do a test with 2" thick 703 and get great absorption at low freqs if you can get enough edge area because you can make the edges act like 2 foot thick 703. Will they be sued? No, because the plaintiff would have to demonstrate financial losses from using the product. Any consumer who has that much interest in the acoustical performance would have designed the installation conservatively anyway. And I'm sure in the specs it says something like "actual performance will vary by application and installation" letting them off the hook.
 
I don't think it says anything like that on the specs. If it had i would have looked for something else.
 
pandamonk said:
I don't think it says anything like that on the specs. If it had i would have looked for something else.

Almost all specs for building materials say that, but you gotta look real hard.
 
One question about cutting the 703 into triangles and stacking it on the corner of any room... I know some people are really sensitive to particles of fiberglass on the air... can i have this kind of problem by using this method?
Thanks!
 
JuliánFernández said:
One question about cutting the 703 into triangles and stacking it on the corner of any room... I know some people are really sensitive to particles of fiberglass on the air... can i have this kind of problem by using this method?
Thanks!

Yeah, you'd probably stir up a lot of dust.

You could do this and have less exposed edges.

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