Which has a bigger cup — Bach 12C or Bob Reeves 4G?

The Bob Reeves 4G has a cup diameter of 26.00 mm / 1.0236 in compared to 24.50 mm / 0.9646 in on the Bach 12C — a difference of 1.50 mm / 0.0591 in. A wider cup generally produces a fuller, darker tone but requires more air support.

How does cup depth compare between Bach 12C and Bob Reeves 4G?

The Bob Reeves 4G has a very deep cup while the Bach 12C has a shallow cup. Deeper cups favor a darker, richer sound; shallower cups provide more brightness and easier upper register.

Bach 12C vs Bob Reeves 4G

Name: Bob Reeves 4G
Brand: Bob Reeves

The Bob Reeves 4G has a wider cup diameter, the Bob Reeves 4G features a deeper cup.

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

Bach 12C

• Trombone

Material—

Best suited for

📣High-volume projection — open throat for power

Mouthpiece B

Bob Reeves 4G

• Trombone

Material—

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.

Open in interactive tool + Add third mouthpiece Bach 12C details Bob Reeves 4G details Bach 12C equivalents Bob Reeves 4G equivalents

Bach 12C vs Bob Reeves 4G

Playing Characteristics

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Which is better?

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