GR Technologies E62FD vs GR Technologies 63FD
The GR Technologies 63FD has a wider cup diameter.
The internal diameter of the cup, measured at the widest point inside the rim.
Mouthpiece A
GR Technologies E62FD
• Flugelhorn
Cup diameter15.75 mm / 0.6201 in
vs
Mouthpiece B
GR Technologies 63FD
• Flugelhorn
Cup diameter16.00 mm / 0.6299 in
Cup Diameter
The GR Technologies 63FD has a cup diameter of 16.00 mm / 0.6299 in compared to 15.75 mm / 0.6201 in on the GR Technologies E62FD — a difference of 0.25 mm / 0.0098 in. A wider cup generally produces a fuller, darker tone but requires more air support.
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.