Bach 5C vs Schilke M2X
The Schilke M2X has a wider cup diameter, the Schilke M2X has a larger throat opening.
Cup Diameter
The Schilke M2X has a cup diameter of 17.27 mm / 0.6799 in compared to 16.25 mm / 0.6398 in on the Bach 5C — a difference of 1.02 mm / 0.0402 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 Schilke M2X has a wider throat (3.84 mm / 0.1512 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.