IIRC this is the basis for his Excalibur mouthpieces.

--Joe C.

Paul Coats <tenorman@...> wrote:
> Ralph Morgan, in his column in Saxophone Journal, described an 
> experiment where he filed off material on the outside of a hard rubber 
> mouthpiece.  As he removed material the tone became richer, more 
> lively.  As it became thinner, the material vibrated more.  But suddenly 
> as the approached very thin, the tone became too extreme, edgy.