Bach 5 vs Monette TS6 S1
The Bach 5 has a wider cup diameter, the Monette TS6 S1 has a larger throat opening.
Cup Diameter
The Bach 5 has a cup diameter of 25.50 mm / 1.0039 in compared to 25.40 mm / 1.0000 in on the Monette TS6 S1 — a difference of 0.10 mm / 0.0039 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 Monette TS6 S1 has a wider throat (6.63 mm / 0.2610 in vs 5.85 mm / 0.2303 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.