Bach 24W vs Yamaha BB-67
The Yamaha BB-67 has a wider cup diameter, the Bach 24W has a larger throat opening.
Cup Diameter
The Yamaha BB-67 has a cup diameter of 31.93 mm / 1.2571 in compared to 31.25 mm / 1.2303 in on the Bach 24W — a difference of 0.68 mm / 0.0268 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 24W has a wider throat (9.00 mm / 0.3543 in vs 8.35 mm / 0.3287 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.