Bach 7 vs Bruno Tilz 231-C 4
The Bach 7 has a wider cup diameter, the Bruno Tilz 231-C 4 features a deeper cup, the Bach 7 has a larger throat opening.
Cup Diameter
The Bach 7 has a cup diameter of 33.25 mm / 1.3091 in compared to 33.00 mm / 1.2992 in on the Bruno Tilz 231-C 4 — a difference of 0.25 mm / 0.0098 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
The Bruno Tilz 231-C 4 has a deep cup while the Bach 7 has a medium cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.
Throat Diameter
The Bach 7 has a wider throat (9.00 mm / 0.3543 in vs 8.20 mm / 0.3228 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.