Bach 1½C vs Bob Reeves 43.5/S/69
The Bob Reeves 43.5/S/69 has a wider cup diameter, the Bach 1½C features a deeper cup.
The internal diameter of the cup, measured at the widest point inside the rim.
Mouthpiece A
Bach 1½C
• Cornet
Cup diameter17.00 mm / 0.6693 in
vs
Mouthpiece B
Bob Reeves 43.5/S/69
• Cornet
Cup diameter17.26 mm / 0.6795 in
Cup Diameter
The Bob Reeves 43.5/S/69 has a cup diameter of 17.26 mm / 0.6795 in compared to 17.00 mm / 0.6693 in on the Bach 1½C — a difference of 0.26 mm / 0.0102 in. A wider cup generally produces a fuller, darker tone but requires more air support.
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.