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Armstrong Optima 3251 HumiGuard Plus Corner traps
Old 2 weeks ago
Armstrong Optima 3251 HumiGuard Plus Corner traps


Basement project Studio
Length 308"
width 131"
Height 90"

The room is pretty tight but the window and door aren't sealed so there is some low frequency energy that gets in and gets out.

My front wall is 2 layers of R30 covered with Muslin.
I have a bunch of random traps from old studios. Combination of R30, 703, 705, Roxul 60. Different sizes and depths. I also have a bunch of R30 stuffed in some boxes and some still in the wrapping in the back corners for now.

The room is behaving much as the REW calculator would predict at listening position.

There is a big mode around 40Hz and another around 70Hz.

I was given some Armstrong Optima Tegular 3521 ceiling tiles LINK.

I have 48 - 24"'x24" and 7.5 - 72"x24" ceiling tiles. They are listed as NRC 0.95.

I was thinking about using them to make wall ceiling corner traps. Basically I would just put them up by wedging them between a piece of trim on the wall and a piece of trim on the ceiling. I would fill the space behind them with R30. Essentially they would just be there to dress up the front of the R30. Although I suppose if I leave facing on them then they could function like a range limiter.

Is this a good use for those materials? Should I remove the facing?

It took some quick measurements with my HS80Ms, but I haven't brought subs in yet.

Attached REW file and screenshot anyway, because it might be useful. It's been a while since I've taken measurements, so I'm sure that I did not set it up perfectly.

Any advice would be appreciated.


Attached Thumbnails
Armstrong Optima 3251 HumiGuard Plus Corner traps-spl.jpg   Armstrong Optima 3251 HumiGuard Plus Corner traps-img_9044.jpg  
Attached Files
File Type: zip (100.3 KB, 10 views)

Last edited by Grovestand; 2 weeks ago at 08:55 PM..
Old 2 weeks ago
In case I wasn't totally clear about what I'm thinking about doing, here are a couple sketches of it that I made in blender:

Pink = R30
Blue = drywall
Dark Gray = floors
Black = furring strips
White = Ceiling/through door

Also here are my untreated results from years ago.\

Edit, just realized that those are with my HS10W. I will bring it downstairs and install it.

Attached Thumbnails
Armstrong Optima 3251 HumiGuard Plus Corner traps-armstrong-traps-back-wall.jpg   Armstrong Optima 3251 HumiGuard Plus Corner traps-armstrong-traps-door.jpg  

Last edited by Grovestand; 2 weeks ago at 08:57 PM..
Old 2 weeks ago
NRC 0.95 at what frequency?

It seems you have a few bass traps but now you want to install ceiling tiles? For what? I don't get it.
Old 2 weeks ago
Thanks for your reply!

I got them for free and I thought I’d use them.

I have a few bass traps but I would like to even out my room some more. I would prefer to use material that I already have to save money.

Aesthetically I think that ceiling tiles will look better and be less work then building a frame for R30 and then covering it with fabric.

I have treated the front wall, I have a plan for the rear wall, I know how to treat FR points. I’ve had good results from thick traps straddling ceiling wall corners, but I haven’t had great luck making them look good.

I think I could kill a few birds with a couple stones that I already have.

The only data I can find on the tiles is that they are NRC 0.95. Apparently the tiles are fiberglass and “Durabrite Acoustically transparent membrane.”

I can’t find any data on what this term means, but I know that people have used drop ceiling tiles with R30 behind them to create large ceiling clouds.

I believe JHBrandt builds a lot of studios like this and he recommends tiles that are at least NRC 0.85 or better.

I’m also wondering if treating wall ceiling corners is going to do much for the modes in my room, but I realize that my next step is taking more measurements with a sub.
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