Which has a bigger cup — Bach 15D or Bach 15EW?

The Bach 15D has a cup diameter of 24.40 mm / 0.9606 in compared to 24.30 mm / 0.9567 in on the Bach 15EW — a difference of 0.10 mm / 0.0039 in. A wider cup generally produces a fuller, darker tone but requires more air support.

How does cup depth compare between Bach 15D and Bach 15EW?

Both mouthpieces share a shallow cup depth, so the sound character from depth alone will be very similar.

Bach 15D vs Bach 15EW

Name: Bach 15EW
Brand: Bach

The Bach 15D has a wider cup diameter.

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 15D

• Baritone / Euphonium

Rim width—

Best suited for

📣High-volume projection — open throat for power

Mouthpiece B

Bach 15EW

• 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.