A simple, easy and $0.05 experiment that you can try is to slide a 1/4", 5/16" or 3/8" metal washer (whichever size fits) up the stem of your mouthpiece. It should rest tight just 1/4" to 1/2" above the insertion line of the mouthpiece into the horn. For a heavier response, use a metal nut instead of a washer; I prefer the washer. I find that you can immediately experience a change in the response of the horn and the overtones. This is one way to liven up a sluggish 8D.
My favorite washer's inner diameter has been enlarged by the use of a rat tail file, to get it to rest at the sweet spot on the mouthpiece, in this case, 1/4" above the leadpipe tip. Regards, Larry _______________________________________________ post: horn@music.memphis.edu unsubscribe or set options at http://music2.memphis.edu/mailman/options/horn/archive%40jab.org