Bach 5G (small shank) vs Denis Wick SM3M
The Denis Wick SM3M has a wider cup diameter, the Denis Wick SM3M has a larger throat opening.
Cup Diameter
The Denis Wick SM3M has a cup diameter of 26.40 mm / 1.0394 in compared to 25.50 mm / 1.0039 in on the Bach 5G (small shank) — a difference of 0.90 mm / 0.0354 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
Both mouthpieces share a very deep cup depth, so the sound character from depth alone will be very similar.
Throat Diameter
The Denis Wick SM3M has a wider throat (7.38 mm / 0.2906 in vs 7.00 mm / 0.2756 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.