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R/E/P => R/E/P Archives => Acoustics in Motion => Topic started by: Sonovo on March 19, 2007, 06:51:40 PM

Title: Absorbtion amount
Post by: Sonovo on March 19, 2007, 06:51:40 PM

How much aborbtion can one typically expect after treating a room (bass traps, primary reflections)?

I was planning on recalibrating my studio this afternoon, as I notice that the calibrated levels I had been using before treatment are now too low.

Upon measuring, it appears that I've lost approx 15dB (using pink noise, C weighted slow response).

5dB I've accounted for (upgraded my DAC with lower output than the previous one), but should superchunks and some Rockwool bring down the overall level by 10dB?

I'm asking because I wonder if there isn't something else going on that I simply haven't noticed while I was busy getting set up for measurements this afternoon.

Cheers,
Thor

Title: Re: Absorbtion amount
Post by: Ethan Winer on March 20, 2007, 04:57:14 PM

Thor,

> Upon measuring, it appears that I've lost approx 15dB (using pink noise, C weighted slow response). <

That seems high. In most cases adding bass traps increases the perceived level of bass in a room. Not just perceived, but also what's measured. Nulls are at least as big a problem as peaks. At mid and high frequencies I'd think you could lose a few dB, but 15 is probably due to something else having changed.

--Ethan

Title: Re: Absorbtion amount
Post by: Sonovo on March 20, 2007, 05:39:39 PM

Thanks Ethan,

That's what I've pretty much surmised fromwhat I've read and what other acousticians have told me.

I guess I'll go through the entire chain and see if I can figure out what happened.

Cheers,
Thor

Title: Re: Absorbtion amount
Post by: Tom C on March 20, 2007, 06:53:39 PM

Thor Legvold wrote on Tue, 20 March 2007 22:39

Thanks Ethan, That's what I've pretty much surmised fromwhat I've read and what other acousticians have told me. I guess I'll go through the entire chain and see if I can figure out what happened. Cheers, Thor

Maybe you've made your measurements exactly in a peak which isn't
there anymore.
I too have increased bass levels since I installed my traps.

Tom

Title: Re: Absorbtion amount
Post by: franman on March 21, 2007, 10:04:55 PM

I wouldn't expect to loose anything as far as acoustic output after properly treating a room.. BUT the observation of your measurement possibly sitting in an old peak that has now been contained are absoultely possible... BUT, measuring broadband with Pink Noise C-Weighted shouldn't be that affected.... IMHO..