8 lb mineral wool, 4 inches thick vs oc 703

[PAPAYAMON]

i found a source for this for $1.20 a sq ft. they are 2 ft x 4 ft sheets. i was hoping to mount directly to the ceiling by covering with black cloth and screwing to the drywall with screws and washers. it just seems so much easier to handle this than messing around with insulation.... and it should be a much cleaner looking install as well.

and for 1.20 a square foot, i could treat all 1300 square feet of my studio .

the data on this is at:

http://www.iig-llc.com/pdfs/IIG402.pdf

it is the 1280 product. Sound Absorption Coefficient at 120hz is 1.11.

any thoughts? of course, i am waffling around like a mad rabbit with all of this. it just seems like this would be a lot easier to handle than the r-30 pink stuff, and look a lot better as well.

i did check at home depot, and i can get 703 at 2 inches for 1.16 a square foot. not bad, but 4 inches of this are nowhere near as good as the 8 lb rockwool at 4 inches. not to mention that the rockwool is about half the price.

[avare]

Originally Posted by PAPAYAMON

i found a source for this for $1.20 a sq ft. they are 2 ft x 4 ft sheets. i was hoping to mount directly to the ceiling by covering with black cloth and screwing to the drywall with screws and washers. it just seems so much easier to handle this than messing around with insulation.... and it should be a much cleaner looking install as well.

and for 1.20 a square foot, i could treat all 1300 square feet of my studio .

the data on this is at:

http://www.iig-llc.com/pdfs/IIG402.pdf

it is the 1280 product. Sound Absorption Coefficient at 120hz is 1.11.

any thoughts? of course, i am waffling around like a mad rabbit with all of this. it just seems like this would be a lot easier to handle than the r-30 pink stuff, and look a lot better as well.

i did check at home depot, and i can get 703 at 2 inches for 1.16 a square foot. not bad, but 4 inches of this are nowhere near as good as the 8 lb rockwool at 4 inches. not to mention that the rockwool is about half the price.

You know that the right treatment is with light ~8" thick amterial like R30. If you want to spend more monsy and get less than best voice acoustics, you can use anything you want. The 1280 is too dense.

Andre

[PAPAYAMON]

Originally Posted by avare

You know that the right treatment is with light ~8" thick amterial like R30. If you want to spend more monsy and get less than best voice acoustics, you can use anything you want. The 1280 is too dense.

Andre

andre, what does the sound absorption coefficient tell me then? if i figure it at 120 hz for r30 at around .96 and for this 4 inch rockwool at 1.11, then isn't the rockwool a better material, or am i overlooking something?

i'll be the first to admit less than expert knowledge, for sure.

[Glenn Kuras]

i did check at home depot, and i can get 703 at 2 inches for 1.16 a square foot. not bad, but 4 inches of this are nowhere near as good as the 8 lb rockwool at 4 inches. not to mention that the rockwool is about half the price.

Either is going to be fine, but if you increase over 6" then I would go with the 703. You can also see if you can find 4 pound in the mineral wool which will work also. Kind of flimsy and harder to work with though.

[Glenn Kuras]

Originally Posted by PAPAYAMON

andre, what does the stc tell me then? if i figure the stc at 120 hz for r30 is around .96 and the stc for this 4 inch rockwool is 1.11, then isn't the rockwool a better material, or am i overlooking something?

i'll be the first to admit less than expert knowledge, for sure.

From the testing I have seen, for thinner panels the more dense will work better. As it gets thicker though it matters less.

[PAPAYAMON]

glenn what do these sound absorption coefficient numbers really tell us? wouldn't 1.11 be a truly outstanding number. or is there more to it than that?

[Glenn Kuras]

Sound transmission class - Wikipedia, the free encyclopedia

[PAPAYAMON]

Originally Posted by Glenn Kuras

Sound transmission class - Wikipedia, the free encyclopedia

oops, i didn't mean stc. i meant sound absorption coefficient . i just got off a grueling 16 hour night shift. the crash is coming soon .

[Glenn Kuras]

Originally Posted by PAPAYAMON

glenn what do these sound absorption coefficient numbers really tell us? wouldn't 1.11 be a truly outstanding number. or is there more to it than that?

1.11 is outstanding but that is for "A" mound. It gets very complicated and there is debate after debate about it, but the bottom line is if the numbers are good then the product is good. BTW having a difference of 1.11 vs say .95 is not a deal breaker. I would view both as great.
Now to totally complicate things, you really should look at the sabins number as that truly is the number that tells you how much a given product will absorb. I could build a bass trap that has a coefficient of 1 but is only 1'x1', which would do very little to nothing at that frequency if I only used one.

[PAPAYAMON]

the biggest difference here would be the relative ease of installation. it's a lot easier to wrap 4 inch thick but dense 2 x 4 tiles in black cloth and screw them into the drywall. the other issue, of course, is how much area to treat. do i really need to treat 100% of the surface area?

obviously, this gets vastly more complicated than i can understand, and pretty darn quickly. the saving grace is that if i can keep adding till it's right. as a lay person, i'd have thought that it would be a lot easier to treat for relatively simple voice teaching video vs music production.