[Nefertiti]

What is the difference?

acoustimax has no handfinish and serial number.
Further? Is it that, for the acoustimax, you have to be lucky with rails and tip?

A couple months ago I tried 4 Acoustimer and 4 Acoutimax. They all played very well. The Acoustimer's chamber seemed to be larger from the ones I played. They were darker sounding than the Acoustimax. All 4 Acousitmax mouthpieces were perfect looking and playing. The chamber looked a tad smaller and the side scooped into the chamber more I think. (or at least the scoop looked different to me. It was very smooth. Not a bump or edge anywhere in the piece. The material that it is made of is a special material that is different than the hard rubber of the Acoustimer. I can't go into details but Frank was telling me all the chemistry and science behind it. The Acoustimax for me was brighter and more powerful than the Acoustimer. The Acoustimer was darker and was warmer sounding. I ended up taking a Acoustimax home after trying them all because I thought it was a great lead alto type of piece.