Bach 4C vs Bruno Tilz 214-12 S
The Bach 4C has a wider cup diameter, the Bach 4C has a larger throat opening.
Cup Diameter
The Bach 4C has a cup diameter of 25.75 mm / 1.0138 in compared to 25.50 mm / 1.0039 in on the Bruno Tilz 214-12 S — 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
Both mouthpieces share a shallow cup depth, so the sound character from depth alone will be very similar.
Throat Diameter
The Bach 4C has a wider throat (5.85 mm / 0.2303 in vs 5.80 mm / 0.2283 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.