Which has a bigger cup — Bach 12C or Bach 5GL?

The Bach 5GL has a cup diameter of 25.50 mm / 1.0039 in compared to 24.50 mm / 0.9646 in on the Bach 12C — a difference of 1.00 mm / 0.0394 in. A wider cup generally produces a fuller, darker tone but requires more air support.

How does cup depth compare between Bach 12C and Bach 5GL?

The Bach 5GL has a 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 Bach 5GL

Name: Bach 5GL
Brand: Bach

The Bach 5GL has a wider cup diameter, the Bach 5GL features a deeper cup, the Bach 5GL has a larger throat opening.

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

The taper behind the throat leading to the shank. Affects projection and tone character.

Mouthpiece A

Bach 12C

• Trombone

Backbore—

Best suited for

📣High-volume projection — open throat for power

Mouthpiece B

Bach 5GL

• Trombone

Backbore—

Best suited for

🎻Orchestral playing — large cup for full, dark tone

📣High-volume projection — open throat for power

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 Bach 5GL details Bach 12C equivalents Bach 5GL equivalents

Bach 12C vs Bach 5GL

Playing Characteristics

What Do These Model Names Mean?

What Changes If You Switch?

Which is better?

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