Fiberglass Facing

[Stabb]

Hi,
I've purchased Johns Manville Spin Glas 2" fiberglass insulation with foil facing.
(this stuff spec-ed better than OC 703)
I'm glueing 2 together to get 4" thick absorbers with no backing.
Should I have the foil facing out?
Thanks.

Aloha,
Stabb

[knightfly]

Depends on what you're trying to do - foil out doesn't change low freq absorption much, but does make things brighter (less High freq. absorption) Foil in gives more uniform absorption, so most times this would be the choice.

If you were to use this as a bass trap and had it away from the wall, then you should remove the foil altogether - otherwise, you would lessen the amount of benefit gotten by spacing the absorbent away from the wall, for the lower frequencies... Steve

[Stabb]

Hi!
Thank you sooo much for your reply.

I installed Acoustic Sciences Corp 'Mix Station' package in my control room.
It is a typical bedroom. I posted a drawing of it on another thread -

http://www.johnlsayers.com/phpBB2/viewtopic.php?t=554

The Mix Station seems to give me a very small sweet spot.
Also I think I have standing waves behind the 3 big wall units.
In fairness to ASC, they say that the sweet spot is within the area the 3 big wall units encompass.

I would like to expand the listening area further toward the back of the room by augmenting the Mix Station with 2' x 4' x 4" thick hanging absorbers on the ceiling and walls (2 - 2' x 4' x 2" glued together).
I've bought enough for 6 hangers.
I have a feeling I'll need more.

The reason I got the faced stuff is I saw that the foil covered fiberglass had the best specs on the bottom and a more even absorption rate lo to high.

Before I posted this thread I tried attaching 2 pieces together and cover the 4" sides with a strip of cotton fabric and am covering the entire piece with burlap.
Man, the foil makes it very easy to work with.

Maybe this will work out for me because the room has thick pile carpeting.
So maybe I'll need less aborption in the high end???

I would like suspend the pieces from the ceiling.
Is this a good idea?
If so, do you think glueing fabric straps to the sides would be a good way to go?
Spray glueing was so easy and quick!

Again, thank you very much for your help!!!
Aloha,
Stabb

[John Sayers]

Hey Stabb - thanks for that - that stuff is the closest equivalent to our Insulco I've seen yet - and it is available with the black facing that I used in left bank.

Here's a PDF of it for others to see

http://www.jm.com/Insulation/Products/D ... _board.pdf

cheers
john

[John Sayers]

Here are the acoustic specs

cheers
john

[Stabb]

John,

I am very happy to be of help.

Aloha,
Stabb

[John Sayers]

Thanks mate - you've no idea how I appreciate the info :)

cheers
john