Which has a bigger cup — Bach 14½D or Bach 4?

The Bach 4 has a cup diameter of 26.00 mm / 1.0236 in compared to 24.50 mm / 0.9646 in on the Bach 14½D — a difference of 1.50 mm / 0.0591 in. A wider cup generally produces a fuller, darker tone but requires more air support.

How does cup depth compare between Bach 14½D and Bach 4?

The Bach 4 has a medium 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 14½D vs Bach 4

Name: Bach 4
Brand: Bach

The Bach 4 has a wider cup diameter, the Bach 4 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 14½D

• Baritone / Euphonium

Rim width—

Best suited for

📣High-volume projection — open throat for power

Mouthpiece B

Bach 4

• 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.