Bob Reeves Dynamic Mass Mouthpieces are built using a formula
that determines how the mouthpiece is balanced from the cup
depth. This includes the bore, backbore, and overall length.
They are not heavy mass mouthpieces but get their name from the
fact that, as their overall length changes from model to model,
their mass changes or is "Dynamic."
Dynamic Mass Mouthpieces behave differently
than conventional mouthpieces. Our experience has shown that
players often find it desirable to play Dynamic Mass Mouthpieces
that are somewhat deeper than their usual mouthpiece.