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Is There A Calculator These Types of Traps?:
Old 1 week ago
  #1
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Is There A Calculator These Types of Traps?:

Have 2 feet of space on my back wall and I want to build a trap like the attached photo using rigid fibreglass instead of the carbon. The picture seems to be about 12" deep. Am wondering how I could adjust that layout for 24" depth. The PAC doesn't accommodate the stiff membranes and only allows up to 4 points of layer data. Any suggestions would be much appreciated.
Thanks in Advance
Sal
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Is There A Calculator These Types of Traps?:-1570542504841.jpg  
Old 1 week ago
  #2
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What frequency range are you trying to absorb? With 2' I recommend 1' of pink fluffy with a 1' air gap behind the insulation. Flat absorption down to under 30 Hz.
Old 1 week ago
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Quote:
Originally Posted by avare View Post
What frequency range are you trying to absorb? With 2' I recommend 1' of pink fluffy with a 1' air gap behind the insulation. Flat absorption down to under 30 Hz.
Problem frequencies are 44hz and 128hz mostly. When i ran that spec you gave me through the PAC i get about .6 @ 40hz is that considered good? I was trying to aim for between .8 and .9 in that frequency range
Old 1 week ago
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Quote:
Originally Posted by Trackhouse1 View Post
Problem frequencies are 44hz and 128hz mostly. When i ran that spec you gave me through the PAC i get about .6 @ 40hz is that considered good? I was trying to aim for between .8 and .9 in that frequency range
0.6 is quite usable. You do not appear afraid of math. Using the room dimension, calculate the RT60 for that mode based on the dimension and .4 reflectivity. I think you will be pleasantly surprised.

What GFR did you use?
Old 1 week ago
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Going through the calculations the RT60 is around 200 ms. Quite respectable to EBU Tech 3276.
Old 1 week ago
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Quote:
Originally Posted by avare View Post
0.6 is quite usable. You do not appear afraid of math. Using the room dimension, calculate the RT60 for that mode based on the dimension and .4 reflectivity. I think you will be pleasantly surprised.

What GFR did you use?
1479 is the GFR I found for Johns Manville r19
Old 1 week ago
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Quote:
Originally Posted by Trackhouse1 View Post
1479 is the GFR I found for Johns Manville r19
Wow! 5,000 is what i use for "pink fluffy"
It shows around [email protected]
Old 1 week ago
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Quote:
Originally Posted by avare View Post
Wow! 5,000 is what i use for "pink fluffy"
It shows around [email protected]
Would you suggest a higher GFR for this application? I have access to OC pink panther here in Jamaica but have been unable to get a definitive number on its GFR. From what I have gathered it seems to fluctuate from 2500 - 5000
Old 1 week ago
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Quote:
Originally Posted by Trackhouse1 View Post
Would you suggest a higher GFR for this application? I have access to OC pink panther here in Jamaica but have been unable to get a definitive number on its GFR. From what I have gathered it seems to fluctuate from 2500 - 5000
It is that I have never read of a GFR so low
The main thing with this application in the GFR ramge is price.

Enjoy!
Old 1 week ago
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[QUOTE=avare;14255942]It is that I have never read of a GFR so low
The main thing with this application in the GFR ramge is price.

Enjoy![/QUOTE

I found the info on here I am attaching the file. It seemed accurate to me based on some density/gfr graphs I've seen floating around. The density of the r19 brands seems to be roughly 3 to 4 pounds per sq foot
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Is There A Calculator These Types of Traps?:-screen-shot-2014-05-23-12.16.07-pm.jpg  
Old 5 days ago
  #11
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[QUOTE=Trackhouse1;14256215]
Quote:
Originally Posted by avare View Post
It is that I have never read of a GFR so low
The main thing with this application in the GFR ramge is price.

Enjoy![/QUOTE

I found the info on here I am attaching the file. It seemed accurate to me based on some density/gfr graphs I've seen floating around. The density of the r19 brands seems to be roughly 3 to 4 pounds per sq foot
If that chart is accurate, I think you just found the holy grail for deep fibre based absorbers.
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