Ummmm! I'll take mine with extra mayo. But seriously, I was thinking of taking some of my extra 1" thick Linacoustic RC and making some bass traps. If I took the linacoustic and cut two pieces, say 2' by 4', then spray some adhesive and stuck them together so the reinforcement was on the outside, would it be effective to place it to span the corners of my room?

Would it be more effective or efficient to make a 'superchunk' trap with triangular pieces completely filling the airspace of the corner? If I did this would the reinforcment need to be removed in the middle of a multilayered system?

I'm sure someone with more knowledge than me will answer this, but my suspicion is that 1" Linacoustic won't work very well as a bass trap. It's much better with the mid and high frequencies, as far as I know.

I used 2" 703 for my basstraps. It's cut into triangles and stacked floor to ceiling in the front corners of the room. I wrapped the stacks with speaker fabric and stapled the entire assembly to the walls to keep it in place. It's not pretty but it's hidden behind the front proscenium and never seen anyway.

Here's a pic:

http://i8.photobucket.com/albums/a27/drinpsmith/basstrap.jpg

The cleats on the right side and the frame in the left center are for the edge of my proscenium frames. This was taken while the carpet was going in so the room was disassembled. The apparatus at the top of the pic is the ultra-quiet bathroom extractor fan I installed to keep the room cool. I had to cut away the edge of the fan cowling to fit it behind the proscenium. So far the room hasn't been warmer than 74 degrees, and it's getting up into the 90's here at the moment. :)

-drin

I'm sure someone with more knowledge than me will answer this, but my suspicion is that 1" Linacoustic won't work very well as a bass trap. It's much better with the mid and high frequencies, as far as I know.

Thanks, drin. Actually, by sticking the two pieces of 1" linacoustic together I would be creating a 2" thick piece. I was wondering if I could expect the cummulative effect of 2" linacoustic rc or if the reinforcement on both sides would cause a difference. I was trying to get something like Ethan Winer discusses in his FAQ: http://www.ethanwiner.com/acoustics.html#fiberglass%20traps

Thanks again for the pic. Looks like you've got a 'cool' solution to the heat build up problem.

Thanks, drin. Actually, by sticking the two pieces of 1" linacoustic together I would be creating a 2" thick piece. I was wondering if I could expect the cummulative effect of 2" linacoustic rc or if the reinforcement on both sides would cause a difference.

I don't think it's the thickness that makes that great a difference between 1" Linacoustic and 2 layers stacked together. The density of Linacoustic vs. 703 is noticeably different. I can't say for sure since my acoustics knowledge is next to nothing, but my supposition is that it's that density difference in combination with the thickness difference that changes the absorptive frequencies of the material.

For example, if I put two inches of lead sheet together and fire an arrow at it, it'll have far more absorptive capability than two inches of feather pillow. :D

-drin

This will work as a "bass trap," but better is to use 4" thickness, and better still is to fill the entire corner (including the air space) with this fiberglass. See:

http://forum.studiotips.com/viewtopic.php?t=534
http://forum.studiotips.com/viewtopic.php?t=535
Linacoustic RC is very similar in properties to the OC 703 mentioned.

Regards,
Terry

If I took the linacoustic and cut two pieces, say 2' by 4', then spray some adhesive and stuck them together so the reinforcement was on the outside, would it be effective to place it to span the corners of my room?

There's no need to glue them together. Just stack them adjacent and wrap your sandwich (yumm) with fabric. That will hold the two pieces together fine. But two inches thick is not enough for bass trapping. If you're using plain fiberglass, four inches thick is a better minimum.

Would it be more effective or efficient to make a 'superchunk' trap with triangular pieces completely filling the airspace of the corner?

Solid fill is better than a four inch thick panel, but the bang for the buck is lower. That is, twice as much material does not give twice the absorption. See my Density Report (http://www.ethanwiner.com/density.html) where I compare three densities of rigid fiberglass, with and without the paper facing. Relevant here is the additional comparison of the same amount of material used to make thick traps and thin traps. Having twice as many 3-inch traps was noticeably better than half as many 6-inch traps.

--Ethan

Is FSK the same as FRK? In your Photos Ethan, it looks like tin foil, is that the FRK material we want?

Here are some pics of how I built mine awhile back...I used molding strips filled them with linacoustic (equivalent) and covered them with GOM. Easy to do and did make a difference when I took my bass measurements.

http://img2.putfile.com/thumb/7/19219411163.jpg (http://www.putfile.com/pic.php?img=5970001)

http://img2.putfile.com/thumb/7/19219411165.jpg (http://www.putfile.com/pic.php?img=5970002)

http://img2.putfile.com/thumb/7/19219411128.jpg (http://www.putfile.com/pic.php?img=5970004)

http://img2.putfile.com/thumb/7/19219411240.jpg (http://www.putfile.com/pic.php?img=5970006)

http://img2.putfile.com/thumb/7/19219411234.jpg (http://www.putfile.com/pic.php?img=5970007)

-Jason

I used corner stacks of 2 inch Linacoustic and it worked nicely. In fact, the rear 7.1 surrounds are in small boxes in the middle of them. See the black 45 degree corners in photo. NOTE: Lens make theater long longer and narrower than it actually is. PJ is temporary mounting.

http://nightskypictures.com/theater/back.jpg

Wow! Incredible pics, thanks to all. Looks like the best thing to do in the superchunk method filling the corners and the air space behind them (as many as possible - right Ethan).

Is FSK the same as FRK? In your Photos Ethan, it looks like tin foil, is that the FRK material we want?

Yes, they're the same.

--Ethan