Bach 6½AL (small shank) vs Denis Wick SM3.5
The Denis Wick SM3.5 has a wider cup diameter, the Denis Wick SM3.5 features a deeper cup, the Denis Wick SM3.5 has a larger throat opening.
Cup Diameter
The Denis Wick SM3.5 has a cup diameter of 26.40 mm / 1.0394 in compared to 25.40 mm / 1.0000 in on the Bach 6½AL (small shank) — a difference of 1.00 mm / 0.0394 in. A wider cup generally produces a fuller, darker tone but requires more air support.
Cup Depth
The Denis Wick SM3.5 has a very deep cup while the Bach 6½AL (small shank) has a deep cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.
Throat Diameter
The Denis Wick SM3.5 has a wider throat (7.62 mm / 0.3000 in vs 6.63 mm / 0.2610 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.