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Post by paulcross on Feb 3, 2021 21:18:58 GMT
I’ve recently used rockwool rwa45 in some diy corner bass traps. I have some insulation left over and was wondering if this type of rockwool would also be suitable for acoustic panels? The rockwool density is 45kg/m3 but seen that a lot tend to use 60kg/m3 for acoustic panels. Is 45 too low?
For the record the insulation is 50mm thick so if suitable would you recommend doubling up the insulation to make the panel 100mm thick to be more effective?
Any help appreciated !
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Post by Hexspa on Feb 3, 2021 22:41:20 GMT
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Post by paulcross on Feb 4, 2021 7:46:46 GMT
Thanks for the link ! Not the most knowledgeable on this subject so all the figures are pretty confusing but will try and make sense of it. Do you have any preference on what density to use in panels?
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Deleted
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Post by Deleted on Feb 4, 2021 9:00:11 GMT
That 60kg/m3 is too dense, if you make any thicker than say 50mm or 100mm. The usual problem is to find low enough GFR for bass traps. Remember, 50mm or 100mm are not "basstraps". You usually end up sucking too much low mids and lower bass and sub bass still out of control = horrible sounding room. (I basically had that at one point).
I don't know did I ask you before, but what is your room dimensions? And treatment goals?
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Post by paulcross on Feb 5, 2021 9:23:09 GMT
That 60kg/m3 is too dense, if you make any thicker than say 50mm or 100mm. The usual problem is to find low enough GFR for bass traps. Remember, 50mm or 100mm are not "basstraps". You usually end up sucking too much low mids and lower bass and sub bass still out of control = horrible sounding room. (I basically had that at one point). I don't know did I ask you before, but what is your room dimensions? And treatment goals? The room is really small... just a make shift room for tracking drums etc. It’s a rectangle I’d say about 3.5m long. Tbf I’m struggling to source any 60kg/m3 insulation, would the 50mm 45kg/m3 off cuts I have be ok for the panels ? Would be handy if so as I already have enough to make 1 or 2 panels.
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Post by Deleted on Feb 5, 2021 14:56:30 GMT
Is 50mm thickest you can go ?
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Post by paulcross on Feb 5, 2021 16:04:57 GMT
Is 50mm thickest you can go ? Could double it up and make it 100mm thick panel?
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Post by Hexspa on Feb 7, 2021 6:10:12 GMT
That 60kg/m3 is too dense I think this depends, Pasim. Different densities have different absorption coefficients. For example, the IIG mineral wool I use is 8lb/ft3 (128kg/m3) and it works well at 4" (100mm). These are not the spongy batts like Safe n' Sound but proper rigid panels like OC 705.
Paul, what you're looking for in the Bob Golds link is absorption coefficients as close to 1.00 as possible; any differences less than 0.15 is irrelevant so 0.85 is just as good as 1.00. The key details to bear in mind are the thickness for each entry and whether it was measured 'on wall', with a gap, or with FRK or unfaced.
To your original question: you need to find a material's absorption coefficient with the details I mentioned. You can't always get all of them so you have to estimate or compare different entries like 'on wall' to 'on wall' even if you plan to use a gap.
A 50mm panel is not going to give you a result we can recommend. 100mm is minimum for music and 200mm is ideal for a given area of surface coverage - preferably as high as 20%. Beyond 200mm, you can use fluffy insulation as thick as you want.
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