Acoustic Panels

[95RCode]

After setting up my system as good as I possibly can using REW and a BFD I have some issues that room placement and EQ will not take care of. Most of the issues are above 70Hz. I would like to start with some DIY corner traps. I found some fiberglass ceiling panels at Home Depot that might work. Does anyone have any idea what type of fiberglass is used on these panels:

http://www.armstrong.com/pdbupimages/182868.pdf

It appears to be similiar to OC703 or 705 but thinner. It comes in cases of 16 and they are 5/8" thick and sized 2' by 4'. Of course the vinyl facing would have to be peeled off. I don't have a local supplier that I can find for OC703 or Mineral Wool. So anything else would have to be shipped in.

I'm limited in my corner area due to either windows or door openings. But I have about 16" across the face. These would be floor to ceiling traps in at least three corners.

I'm also thinking of purchasing 2 GIK panels for placement behind my main speakers to help with SBIR.

Here's my latest REW readings of both sub and mains:


Any help or advice would be appreciated.

James

[bpape]

OK. You're relatively good down low where it's tough. Now, we just need to figure out WHY you have those couple large dips. You definitely have some boundary issues shown by the 130, 260, 390 dips. Now, is it beside or behind the speakers or both?

The tiles you showed are spec'd at 0.17lb per SQUARE foot. So, seeing as that's about 1/24 foot thick, that comes out to about the same as 703 by the time you do the math. Just look at how many of them you'll have to buy, peel, cut, stack, etc. to make a good chunk style absorber and if that's really cheaper than 703.

Realistically, you could do a 16" square floor to ceiling absorber using those tiles for the faces to keep things in place and just stuff with standard fluffy insulation for a lot less money and 95% of the performance.

Bryan

[95RCode]

Thanks Bryan, really appreciate the help.

bpape wrote:

OK. You're relatively good down low where it's tough. Now, we just need to figure out WHY you have those couple large dips. You definitely have some boundary issues shown by the 130, 260, 390 dips. Now, is it beside or behind the speakers or both?

What's the easiest way to determine what is causing this? Do I need to experiment with panels or can REW help me determine what the cause is?

bpape wrote:

Realistically, you could do a 16" square floor to ceiling absorber using those tiles for the faces to keep things in place and just stuff with standard fluffy insulation for a lot less money and 95% of the performance.

Bryan

When you say "standard fluffy insulation" are you talking about the loose blow in type insulation that I could get at Lowes or Home Depot?

I have a .wma file of the floorplan I need to convert to a jpg if I can figure out how, I'll post that.

If I do my two front corners what type panels would you recommend to place behind my main speakers 242 or 244. This is mainly for HT and is also my living room so I'm trying to the make them look nice and perform.

Thanks again,
James

[bpape]

You can attempt to figure it out based on room size/modes and distances from seating to boundaries and how those interact with those dimensions. For instance, if your ear is 1/2 of the height of the room, then likely, you'll have a modal issue there. If not, then it's likely getting cancelled with another room boundary interaction.

First thing I'd check is what happens if you put 2 thick panels directly behind your head on the rear wall. That's a common place for nulls to occur.

The fluffy insulation is standard fiberglass batt insulation used in walls.

Bryan

[95RCode]

bpape wrote:

First thing I'd check is what happens if you put 2 thick panels directly behind your head on the rear wall. That's a common place for nulls to occur.

Bryan

When you say thick, you mean like 4"?

James

[95RCode]

Bryan,

Are you guys in Atlanta? Reason I ask, I live in Columbus, GA. Wasn't sure of your location, wouldn't mind making a trip up there.

James