Which has a bigger cup — Bach 18 or Schilke 45?

The Schilke 45 has a cup diameter of 24.38 mm / 0.9598 in compared to 24.20 mm / 0.9528 in on the Bach 18 — 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 18 and Schilke 45?

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

Bach 18 vs Schilke 45

Name: Schilke 45
Brand: Schilke

The Schilke 45 has a wider cup diameter, the Schilke 45 has a larger throat opening.

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 18

• Trombone

Backbore—

Best suited for

📣High-volume projection — open throat for power

Mouthpiece B

Schilke 45

• Trombone

Backbore15/64 .2344"

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.