Bach 19 vs Yamaha AH-38D4
The Bach 19 has a wider cup diameter, the Bach 19 has a larger throat opening.
Mouthpiece A
Bach 19
• Baritone / Euphonium
Cup diameter24.00 mm
Cup depthDeep
Rim width—
Throat diameter5.85 mm
Backbore—
Finish—
Material—
Best suited for
Orchestral playing — large cup for full, dark tone
High-volume projection — open throat for power
vs
Mouthpiece B
Yamaha AH-38D4
• Baritone / Euphonium
Cup diameter18.90 mm
Cup depthDeep
Rim width—
Throat diameter5.25 mm
BackboreStandard
Finish—
Material—
Best suited for
Orchestral playing — large cup for full, dark tone
High-volume projection — open throat for power
Cup Diameter
The Bach 19 has a cup diameter of 24.00 mm compared to 18.90 mm on the Yamaha AH-38D4 — a difference of +5.10 mm. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
Both mouthpieces share a deep cup depth, so the sound character from depth alone will be very similar.
Throat Diameter
The Bach 19 has a wider throat (5.85 mm vs 5.25 mm). A wider throat allows more air through, increasing volume and projection but reducing resistance.
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.