to make a calculation of time reverb?

Jul 2, 2011 at 6:28pm

to make a calculation of time reverb?

hi comunity! i would like to calculate the reverberation time of my house with max msp. is it possible with max msp and a microphone for example????

If someone know a patch or tutorial please share!! (^_^)

thanxxxx!!!

#57857
Jul 2, 2011 at 8:03pm

Hi alersito
When you say ‘house’ do you mean the realworld reverberation times of each room/one room, or the theoretical total reverb time of your entire house? The answers also depend on whether you need a mathematical algorithm for recreating the realworld room, or a system for capturing the rooms’ reverb. If it is the former, you first need a measuring tape. Then you should search for ‘Sabine’s formula’, which states that:

Tr = (Kv)/Se

where ‘Tr’ is total reverb time, ‘v’ is the volume of the room in meters cubed, ‘Se’ is the effective absorbtion area (m2) and ‘K’ is a constant (0.16). ‘Se’ itself is dependent on a number of factors, which can easily be determined if you search for ‘absorbtion coefficient’.

HTH

Brendan

#207569
Jul 2, 2011 at 8:13pm

…and here’s an example of how to work out ‘Tr’, based on given room dimensions and materials….

Attachments:
  1. TrExample.pdf
#207570
Jul 2, 2011 at 8:28pm

thankss n00b_meister i want to say the realworld reverberation time. playing a pink noise and then calculating the reverberation time.

#207571
Jul 2, 2011 at 10:30pm

OK, I think I understand; by ‘calculate’ you mean ‘capture’, like an impulse response? Sending a short burst of noise into the room via loudspeaker and then capturing the reverberations? Most sources recommend using a 0db burst of white noise for the duration of 1 sample.

The practical application of this is beyond me I’m afraid, but here’s an article I found via google, on convolution reverb, which may or may not help:

http://www.earlevel.com/main/1997/01/19/a-bit-about-reverb/

Brendan

#207572
Jul 2, 2011 at 10:49pm

thanks brendan.

i think that could be possible calculate the Tr using a source with pink noise and 100 dB. when the source stop send a bang to a clock and when the level decrease 60dB send another bang and stimate the time between the 2 bangs.

i dont know if this is ok or not. (^_^)

#207573

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