Which has a bigger cup — Bach 7 or Bach 9?

The Bach 7 has a cup diameter of 24.75 mm / 0.9744 in compared to 24.72 mm / 0.9732 in on the Bach 9 — a difference of 0.03 mm / 0.0012 in. A wider cup generally produces a fuller, darker tone but requires more air support.

How does cup depth compare between Bach 7 and Bach 9?

The Bach 9 has a deep cup while the Bach 7 has a medium cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.

Bach 7 vs Bach 9

Name: Bach 9
Brand: Bach

The Bach 7 has a wider cup diameter, the Bach 9 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 7

• Baritone / Euphonium

Backbore—

Best suited for

📣High-volume projection — open throat for power

Mouthpiece B

Bach 9

• Baritone / Euphonium

Backbore—

Best suited for

🎻Orchestral playing — large cup for full, dark tone

📣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.