Which has a bigger cup — Bach 15E or Yamaha SL-46BS?

The Yamaha SL-46BS has a cup diameter of 24.58 mm / 0.9677 in compared to 24.40 mm / 0.9606 in on the Bach 15E — a difference of 0.18 mm / 0.0071 in. A wider cup generally produces a fuller, darker tone but requires more air support.

How does cup depth compare between Bach 15E and Yamaha SL-46BS?

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

Bach 15E vs Yamaha SL-46BS

Name: Yamaha SL-46BS
Brand: Yamaha

The Yamaha SL-46BS 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 15E

• Trombone

Rim width—

Best suited for

📣High-volume projection — open throat for power

Mouthpiece B

Yamaha SL-46BS

• Trombone

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.