8 pound mineral wool

[jayjames]

I have a good source for 8-pound mineral wool. Is this too dense for absorption purposes? I know OC 705 is 6-pound density. What's the word on denser material?
Jay

[tINY]

Ethan and Bryan and maybe Scott should be by sometime... (oh yeah, and Glenn)

But, the data suggests that for bass traping, there is an optimal density with the Owens Corning product that makes the 703 slightly better than the 705 for corner traps.

Of course, measuring absorbtion below 120 Hz is tricky and the differences are slight. Hell, Rockwool may be sufficiently different somehow that the optimal density may be higher or lower....




-tINY

[cletus]

I've made several bass traps out of 4x2 8 pound rock/mineral wool. I had to start using it as all the Owen Corning 705 started getting expensive. I believe I had asked over on Ethans site and it was said to be just as effective. I wrapped it in nice fabric and hung it off the wall on 1/2 inch furring strips. Hope that helps.

[jayjames]

Thanks for the replies. That's good news for me :) My biggest concern was whether this stuff is too reflective for absorbing highs. Time to place an order!

[Glenn Kuras]

Originally Posted by jayjames

Thanks for the replies. That's good news for me :) My biggest concern was whether this stuff is too reflective for absorbing highs. Time to place an order!

8 pound will work VERY WELL for panels up to 6" thick. If filling the FULL corner then go with 4 pound.

Glenn

[jayjames]

Glenn,
My local supplier does not carry anything below 8 pound. If I use it to fill corners will I be doing more harm, or will it just not be as efficient as 4 pound wool?
Jay

[Glenn Kuras]

Originally Posted by jayjames

Glenn,
My local supplier does not carry anything below 8 pound. If I use it to fill corners will I be doing more harm, or will it just not be as efficient as 4 pound wool?
Jay

8 pound should still work pretty well. Hard to say if better or worse then 4 pound. You would need to test it in a lab to know that one.

Glenn

[Ethan Winer]

Originally Posted by jayjames

I have a good source for 8-pound mineral wool. Is this too dense for absorption purposes? I know OC 705 is 6-pound density. What's the word on denser material?

It all works well. But if you'd like to see how density affects absorption, my Density Report is just the ticket:

Rigid fiberglass density tests

This report compares rigid fiberglass, not mineral wool, but the same principles apply.

--Ethan

[Glenn Kuras]

Originally Posted by Ethan Winer

It all works well. But if you'd like to see how density affects absorption, my Density Report is just the ticket:

Rigid fiberglass density tests

This report compares rigid fiberglass, not mineral wool, but the same principles apply.

--Ethan

Thanks for posting that Ethan. To bad you did not fill the corner with 3 pound then 6 pound to see which one would work best. Oh well it is not like you can spend every day in that room.

Glenn

[jwl]

I'd also check Bob Golds absorption coefficients site to see if the specific product you are looking at is on there. If so you'll have the specs.

[Glenn Kuras]

Originally Posted by jwl

I'd also check Bob Golds absorption coefficients site to see if the specific product you are looking at is on there. If so you'll have the specs.

Note that those numbers are only for "A" mount in the lab, so when placed in a corner it will react different. We tested the our 244 panel as "A" mount (flat against the floor) and "J" (straddling corners and spaced off the floor) and it is pretty clear there is a difference. So yes check out those numbers, but what you see is not what you might get when placed in the corner, or cut to some size and stacked in the corner.

Sorry for getting all nerdy.


Glenn

[jayjames]

If I were only using panels (no superchunks) in the corners, would it be better to have one panel straddling the corning with an air cushion behind it, or have a panel flat on each wall adjacent to the corner? Did that make sense?

[Glenn Kuras]

Originally Posted by jayjames

If I were only using panels (no superchunks) in the corners, would it be better to have one panel straddling the corning with an air cushion behind it, or have a panel flat on each wall adjacent to the corner? Did that make sense?

You would want the panel to straddle the corner with the sides touching each side wall.
Does that clear it up?


Glenn

[bonneybear]

Hey Jay, I pm'ed you..Im in NJ also...........Mike