Polystyrene Hangers?

[aaronreeves]

Hi all,

I am converting my garage into a studio, the room is 21 feet long, 12 feet wide and 8 feet high in one half of the room and 9 feet tall in the other half.

Here are two pics of the room.
The front half (mixing position) of the room:

FrontOFRoom.jpg

and the back half of the room:

BackOfRoom.jpg

I have currently 4 superchunks in four of the floor to ceiling corners, soffit mounted speakers that don't extend all the way to the ceiling for reason being that I
have planned to superchunk above them.

I also have 4 side wall absorbers (which consist of angled stud walls stuffed with 4" Kanuf RS45 rigid rockwool panels with varying sized acoustic hangers behind
& with loose insulation fill in the tighter ends of the cavities where hangers were harder to install. The absorbers range from being 20" deep to 4")
I plan to add slats to these simply for HF reflection/diffusion etc.

I felt that the lower bass frequencies were more troublesome than the low mids (hence opting for this approach over slat wall resonators - but someone please
correct me if I am barking up the wrong tree here..??)

The back wall currently consists of a 6' x 4' x 6" RS45 absorber with two 2' x 4' x 6" RS45 absorbers laid on top and 2' x 4' x 4" RS45 absorbers at the sides (red)
There are also absorbers at the side walls of the back of the room (1 x 7' x 2' x 6" absorber on one wall and two 2' x 4' x 6" absorbers on the other wall.)
The ceiling currently consists of 4" RS45 panels between the joists and angled 4" RS45 at the side wall ceiling corners.
I also have other broadband absorption panels scattered around at the moment.

I am looking to suspend hangers from the ceiling at the back half of the room in varying sizes to further improve the low frequency response of the room..
(and a hard-backed angled cloud at the front mixing section of the room.)

I have experimented by putting three 8ft long hangers of varying widths at: 22", 21" and 20" at the back ceiling corner of the room.
These hangers were made of 1" thick polystyrene sheets and although the sheets were difficult to suspend
due to less than rigid consistency of the polystyrene, I believe that they improved the low end response of the room
(notably on a few tracks I played the bass felt deeper as was easier to distinguish from other instruments.)

So I am interested to know whether Polystyrene actually works as acoustic hangers or whether it is just acting as regular absorption?

I can get hold of Celotex, which I've read on this forum is a Homasote equivalent.
However I have some more 1" Polystyrene sheets lying around and Celotex isn't that cheap here neither (£10 for 8' x 4' x 1/2" sheet.)

Any thoughts on this would be much appreciated,
Thanks for your time.

Aaron.

[Soundman2020]

So I am interested to know whether Polystyrene actually works as acoustic hangers or whether it is just acting as regular absorption?

It is most likely doing neither, to be honest. Polystyrene is closed-cell, and therefore has very few uses in acoustics. It is not an absorber, since it is closed cell, it is no use in isolation since it is low mass, and it has no structural integrity to speak of. About the only thing it can be used for is thermal insulation.

So it certainly is not working as an absorber, and probably not doing anything useful as a hanger core either. My bet would be that the only reason you heard a change when you put in the existing hangers, would be from the fiberglass or mineral wool wrapped around it, not from the polystyrene itself. I would not use polystyrene for hanger cores: it isn't much like Homasote at all. If you can't get Homasote, then try to find out what they use in your area to make bulletin boards, the kind you often see for pinning notices to with push pins. That's the kind of low density fiber board that you need.

I felt that the lower bass frequencies were more troublesome than the low mids (hence opting for this approach over slat wall resonators - but someone please correct me if I am barking up the wrong tree here..??)

Before making decisions like that just based on feelings, I would rather run a proper acoustic analysis on the room, using REW, to see how it is reacting acoustically right now, objectively, and based on that decide what treatment it still needs.

That would be my approach.


- Stuart -

[aaronreeves]

Thanks for your reply Stuart, I will dispose of the Polystyrene and research an alternative material (such as the pinning notice material.) - hopefully celotex will do.

Im glad I asked before going ahead.

Aaron