Bach 6BM vs Bach Mega Tone Cornet 5B
The Bach Mega Tone Cornet 5B has a wider cup diameter.
The internal diameter of the cup, measured at the widest point inside the rim.
Mouthpiece A
Bach 6BM
• Cornet
Cup diameter16.20 mm / 0.6378 in
vs
Mouthpiece B
Bach Mega Tone Cornet 5B
• Cornet
Cup diameter16.25 mm / 0.6398 in
Cup Diameter
The Bach Mega Tone Cornet 5B has a cup diameter of 16.25 mm / 0.6398 in compared to 16.20 mm / 0.6378 in on the Bach 6BM — a difference of 0.05 mm / 0.0020 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.