Which has a bigger cup — Bob Reeves RP5 or GR Technologies 65SZ?

The GR Technologies 65SZ has a cup diameter of 16.50 mm / 0.6496 in compared to 16.47 mm / 0.6484 in on the Bob Reeves RP5 — a difference of 0.03 mm / 0.0012 in. A wider cup generally produces a fuller, darker tone but requires more air support.

How does cup depth compare between Bob Reeves RP5 and GR Technologies 65SZ?

Both mouthpieces share a shallow cup depth, so the sound character from depth alone will be very similar.

Bob Reeves RP5 vs GR Technologies 65SZ

Name: GR Technologies 65SZ
Brand: GR Technologies

The GR Technologies 65SZ has a wider cup diameter.

Overall Comparison Cup Diameter Cup Depth Rim Width Throat Diameter Backbore Finish Material

Base metal or construction (e.g. brass, stainless steel, plastic). Influences weight, response, and tone color.

Mouthpiece A

Bob Reeves RP5

• Trumpet

Material—

Mouthpiece B

GR Technologies 65SZ

• Trumpet

Material—

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.