Which has a bigger cup — Bach 12 or Bach 14½D?

Both mouthpieces have virtually identical cup diameters at 24.50 mm / 0.9646 in.

How does cup depth compare between Bach 12 and Bach 14½D?

The Bach 12 has a deep cup while the Bach 14½D has a shallow cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.

Bach 12 vs Bach 14½D

Name: Bach 14½D
Brand: Bach

the Bach 12 features a deeper cup.

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

The width of the rim surface that contacts the lips. Wider rims improve endurance; narrower rims improve flexibility.

Mouthpiece A

Bach 12

• Baritone / Euphonium

Rim width—

Best suited for

🎻Orchestral playing — large cup for full, dark tone

📣High-volume projection — open throat for power

Mouthpiece B

Bach 14½D

• Baritone / Euphonium

Rim width—

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.