Which has a bigger cup — Bob Reeves 4G or Bob Reeves CV?

The Bob Reeves CV has a cup diameter of 29.50 mm / 1.1614 in compared to 26.00 mm / 1.0236 in on the Bob Reeves 4G — a difference of 3.50 mm / 0.1378 in. A wider cup generally produces a fuller, darker tone but requires more air support.

How does cup depth compare between Bob Reeves 4G and Bob Reeves CV?

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

Bob Reeves 4G vs Bob Reeves CV

Name: Bob Reeves CV
Brand: Bob Reeves

The Bob Reeves CV has a wider cup diameter.

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

The width of the rim surface that contacts the lips. Wider rims improve endurance; narrower rims improve flexibility.

Mouthpiece A

Bob Reeves 4G

• Trombone

Rim width—

Best suited for

🎻Orchestral playing — large cup for full, dark tone

Mouthpiece B

Bob Reeves CV

• Trombone

Rim width—

Best suited for

🎻Orchestral playing — large cup for full, dark tone

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.