Bach 17 vs Bach 18
Both mouthpieces share similar core dimensions — the differences are in the details.
The internal diameter of the cup, measured at the widest point inside the rim.
Mouthpiece A
Bach 17
• Trombone
Cup diameter24.20 mm / 0.9528 in
Best suited for
High-volume projection — open throat for power
vs
Mouthpiece B
Bach 18
• Trombone
Cup diameter24.20 mm / 0.9528 in
Best suited for
High-volume projection — open throat for power
Cup Diameter
Both mouthpieces have virtually identical cup diameters at 24.20 mm / 0.9528 in.
Which is better?
Neither mouthpiece clearly dominates the other — the right choice depends on your embouchure, playing style, and the sound you're after. Try both if possible.