Which has a bigger cup — Bach 12E or Bach 18?

The Bach 12E has a cup diameter of 24.50 mm / 0.9646 in compared to 24.20 mm / 0.9528 in on the Bach 18 — a difference of 0.30 mm / 0.0118 in. A wider cup generally produces a fuller, darker tone but requires more air support.

How does cup depth compare between Bach 12E and Bach 18?

The Bach 18 has a medium cup while the Bach 12E has a shallow cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.

Bach 12E vs Bach 18

Name: Bach 18
Brand: Bach

The Bach 12E has a wider cup diameter, the Bach 18 features a deeper cup.

Overall Comparison Cup Diameter Cup Depth Rim Width Throat Diameter Backbore Finish Material

The taper behind the throat leading to the shank. Affects projection and tone character.

Mouthpiece A

Bach 12E

• Trombone

Backbore—

Best suited for

📣High-volume projection — open throat for power

Mouthpiece B

Bach 18

• Trombone

Backbore—

Best suited for

📣High-volume projection — open throat for power

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.