Denis Wick 4 vs Denis Wick 5L
The Denis Wick 4 has a wider cup diameter, the Denis Wick 4 has a larger throat opening.
Cup Diameter
The Denis Wick 4 has a cup diameter of 30.50 mm / 1.2008 in compared to 30.00 mm / 1.1811 in on the Denis Wick 5L — a difference of 0.50 mm / 0.0197 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 4 has a wider throat (8.27 mm / 0.3256 in vs 7.89 mm / 0.3106 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.