[jtwrace]

Has anyone used this http://www.soundprooffoam.com/quiet-batt-insulation.html inside a sub?  I am thinking of using this along with the Acoustastuff from parts express.  Thoughts?

[JoshK]

Here is the info that matters....

R A NDOM SOUND ABSORPTION / NOISE REDUCTION
Freq. Hz 125 250 500 1000 2000 4000 NRC
R 13 0.39 0.86 0.99 0.92 0.96 1.01 0.95
R 19 0.60 1.08 1.02 0.96 1.02 1.01 1.00

Now maybe someone who knows what those should be compared to other sound absorbtion materials can help you decifer if that is a good product.

Note though that data stops at 125hz, right when data would start to matter for this application.  Given the appreciable decline from 250hz to 125hz, it wouldn't suggest a great deal of optimism is warranted.

[Vapor Audio]

Here is the info that matters....

R A NDOM SOUND ABSORPTION / NOISE REDUCTION
Freq. Hz 125 250 500 1000 2000 4000 NRC
R 13 0.39 0.86 0.99 0.92 0.96 1.01 0.95
R 19 0.60 1.08 1.02 0.96 1.02 1.01 1.00

Now maybe someone who knows what those should be compared to other sound absorbtion materials can help you decifer if that is a good product.

Note though that data stops at 125hz, right when data would start to matter for this application.  Given the appreciable decline from 250hz to 125hz, it wouldn't suggest a great deal of optimism is warranted.

Those NRC numbers are pretty good, but of course we're talking about a R13 and R19 thick layer ... that's a lot for any enclosure.  All sound absorptive materials decrease in effectiveness as frequency drops - the wavelengths become much longer than the material meant to stop them, so instead they just pass right through.

[SPKRDTR]

Has anyone used this http://www.soundprooffoam.com/quiet-batt-insulation.html inside a sub?  I am thinking of using this along with the Acoustastuff from parts express.  Thoughts?

Is this a sealed or ported sub?
If sealed, all you need to use is the Acousta-Stuff or, better yet, fiberglass to increase the effective box volume.
If ported, all you need is a thin layer of acoustic material lining the walls.
The sound deadening properties of the batt insulation material you described above will be of no use since a sub only operates in the 150 hz and lower range where sound dampening materials (e.g. fiberglass, cotton batting, etc.) are not effective anyway. Don't waste your money.

[bpape]

STANDARDIZED data on all materials stops at 125Hz.  That's because below that, it's too room dependent and varies too much from lab to lab.  This does not mean that it doesn't work below that.

Also, R-19 insulation due to it's thickness is actually pretty effective down to around 70Hz or so and somewhat effective below that.  All depends on the situation you have and what you need it to do.

Bryan

[jtwrace]

I was just thinking of using the QuietBatt as well as the Acousta stuff.  The enclosure in an all aluminum "box".  I've had great results just using Acousta stuff with my MDF version but thought I would try the QuietBatt as well. 

bpape-thoughts?