Bach 8 vs Yamaha AH-37C4
The Bach 8 has a wider cup diameter, the Bach 8 has a larger throat opening.
Mouthpiece A
Bach 8
• Baritone / Euphonium
Cup diameter24.75 mm / 0.9744 in
Cup depthMedium
Rim width—
Throat diameter5.85 mm / 0.2303 in
Backbore—
Finish—
Material—
Best suited for
High-volume projection — open throat for power
vs
Mouthpiece B
Yamaha AH-37C4
• Baritone / Euphonium
Cup diameter18.60 mm / 0.7323 in
Cup depthMedium
Rim width—
Throat diameter5.25 mm / 0.2067 in
BackboreStandard
Finish—
Material—
Best suited for
High-volume projection — open throat for power
Cup Diameter
The Bach 8 has a cup diameter of 24.75 mm / 0.9744 in compared to 18.60 mm / 0.7323 in on the Yamaha AH-37C4 — a difference of 6.15 mm / 0.2421 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
Both mouthpieces share a medium cup depth, so the sound character from depth alone will be very similar.
Throat Diameter
The Bach 8 has a wider throat (5.85 mm / 0.2303 in vs 5.25 mm / 0.2067 in). 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.