Posted by JLapaire [ 63.76.208.41 ] on April 13, 2005 at 10:01:22:

In Reply to: Helmholtz resonator posted by Wayne Parham on March 28, 2005 at 14:31:29:

It took 8 or 10 tries to get dialed in, but I finally got the suckers nailed. Picture a 5" square piece of plywood with a 1.5" hole in the middle, then a 1" slice of 4" PVC pipe, then another piece of ply with hole. Exhaust hose runs in one side, another comes out the other side - with a 44dB drop at the target frequency! Magic. One minute you've got an annoying high pitch scream, the next minute there's just a quiet Woosh of air.

Now to come up with a shop-ready version that looks decent, then make 44 of them.

Thanks Wayne, that article provided a good launch.

John

Replies:

• Good Job! - Wayne Parham 13:22:46 04/13/05 (0)