Al Gietzen wrote:

Ernest;

Interesting stuff.  Just a guess; but it seems to me that, while 15 db is an
appreciable reduction, having that reduction only over the 8K to 12K maybe
isn't all that productive.  It would reduce the 'harshness', but isn't the
greatest amplitude at lower frequency?  Also, do you envision that this can
be made into a compact, workable package for aircraft application?

  

Don't know, Al.  That's why I've started my experiments with a wood box and pieces of PVC tube.  I don't want to send much money down a rabbit hole if I can help it.

That said, my experiment box is 3" high, 7" wide and 6" long.  I'm going to see what I can do about getting some stainless sheet cut up, and then some tube welded in.  Then I'll have to find a rotary that I can test it on.  Shouldn't be difficult with Bruce Turrentine being 15min down the road.