Bach 1B vs Bach 5MV
The Bach 1B has a wider cup diameter, the Bach 5MV has a larger throat opening.
Mouthpiece A
Bach 1B
• Cornet
Cup diameter17.00 mm / 0.6693 in
Cup depthDeep
Rim width—
Throat diameter3.66 mm / 0.1441 in
Backbore—
Finish—
Material—
Best suited for
Orchestral playing — large cup for full, dark tone
vs
Mouthpiece B
Bach 5MV
• Cornet
Cup diameter16.25 mm / 0.6398 in
Cup depthDeep
Rim width—
Throat diameter3.81 mm / 0.1500 in
Backbore—
Finish—
Material—
Best suited for
High-volume projection — open throat for power
Cup Diameter
The Bach 1B has a cup diameter of 17.00 mm / 0.6693 in compared to 16.25 mm / 0.6398 in on the Bach 5MV — a difference of 0.75 mm / 0.0295 in. 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 5MV has a wider throat (3.81 mm / 0.1500 in vs 3.66 mm / 0.1441 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.