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Ethan Winer · 13th March 2004

Steve,

> According to everything that I have read, the variable depth of a corner trap makes them the best solution for broadband absorbtion. <

I've never paid to have a variable-depth panel trap tested in an official lab, so I can't say for sure how low a Q such a design will be. My gut feeling is it will not be as broadband as thick dense rigid fiberglass mounted straddling the corner.

> I have never seen a panel design utilizing 1/2" plywood. At some thickness, the plywood has to stop acting as a membrane <

Yes, if you use 1/2 inch plywood you may need to make it 3x6 or 4x8 feet so the plywood will have enough expanse to flex sufficiently. I suppose you could try 3/8 inch plywood and use a larger air gap to achieve a low frequency.

Too bad you're not closer to me. I have four experimental panel traps we built and never sold. They use 1/2 inch plywood and were calculated to have a center frequency of about 50-60 Hz. But they're way too big and heavy to ship. If you're willing to drive to Connecticut to pick them up, you are welcome borrow them and try them out.

--Ethan

13th March 2004	#7
Ethan Winer Gear Guru Joined: Oct 2002 Location: New Milford, CT, USA Posts: 12,329	Steve, > According to everything that I have read, the variable depth of a corner trap makes them the best solution for broadband absorbtion. < I've never paid to have a variable-depth panel trap tested in an official lab, so I can't say for sure how low a Q such a design will be. My gut feeling is it will not be as broadband as thick dense rigid fiberglass mounted straddling the corner. > I have never seen a panel design utilizing 1/2" plywood. At some thickness, the plywood has to stop acting as a membrane < Yes, if you use 1/2 inch plywood you may need to make it 3x6 or 4x8 feet so the plywood will have enough expanse to flex sufficiently. I suppose you could try 3/8 inch plywood and use a larger air gap to achieve a low frequency. Too bad you're not closer to me. I have four experimental panel traps we built and never sold. They use 1/2 inch plywood and were calculated to have a center frequency of about 50-60 Hz. But they're way too big and heavy to ship. If you're willing to drive to Connecticut to pick them up, you are welcome borrow them and try them out. --Ethan __________________ Ethan's audio book is now available!