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GR 3 Rim Compu-Bal trumpet mouthpiece

ProZone Insight

The GR 3 Series cup diameter is similar to a conventional 3 diameter. The 3M is a very popular choice for 3C players looking for a familiar feel but with more core in their sound and more improved articulations. All 3 Series GR Mouthpieces have the same rim and alpha angle. This provides a consistent feel between all GR 3 Series Models, allowing the feel to be the same to easily meet any musical demand. Classic Blank is standard. Symphonic Blank is standard on the HC** model.


3 Series: .660" / 16.76mm

3 Series Rim
The GR 3 Series Rim has a slightly flatter feel than the GR Standard rim.
It may have a familiar feel to conventional 3 players but with GR improvements in comfort and articulations.
All 3 Series Mouthpieces have the same alpha angle.
The bite is softer than the Standard GR Rim and GR E-Rim.
The larger bite radius may make the rim feel larger.
The outside diameter is slightly narrower than the Standard GR Rim.
This is a generous rim with excellent grip and support.

3M - #2 backbore, medium small (0.0806") cup volume, Semi flat rim contour, medium soft bite, medium alpha angle

Quick Comparison - The GR 3M is GRs answer to the very popular bach 3C mouthpiece. The 3M's closest true GR is a 66M but features a slightly wider rim giving a feel similar to the bach. Widely used for Bb,C and Eb trumpet work. As the trend in player is moving towards slightly smaller rims mouthpieces, this is becoming a very popular model.


GR 3M rim Compu-Bal trumpet mouthpiece

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