Mouthpiece Numbers (What do they mean?) – Part II: The Slope

For the majority of single reed players, knowing the tip opening and length of the lay is more than enough information to aid them in their search for the ideal mouthpiece.  But the relationship between the length of the lay and the tip opening are not the whole story.  The shape of the curve, or slope, at key points along the facing are where the true response of the reed, resistance and initial tonal focus are cImagereated.

To discover the shape of the curve, we use the Erick Brand Method and measure the facing at 5 critical points.  To measure these points, we again rely on the graduated glass plate and feeler gauges.


  • A.  Measured with the .0015″ gauge.
  • B.  Measured with the .010″  gauge.
  • C.  Measured with the .024″  gauge
  • D.  Measured with the .034″  gauge
  • E.   Measured with the taper gauge

It is the regions between these measurement points that dictates how the mouthpiece will perform.

  • A to B is a gradual slope and responsible for reed control by lip pressure.
  • B to C is generally called the “resistance” section and contains a point (marked F on the above illustration) that is commonly referred to as the “break” or “pivot”.  This is the portion of the facing where the reed leaves the lay under actual performance and is responsible for tonal control.  The slope becomes somewhat sharper between B and C.
  • C to E is the portion of the facing known as the vent.  For me, this is the part of the mouthpiece that is crucial to the initial response of the reed and articulation.

Now that we have an idea of how the mouthpiece is measured and how each important area of the facing affects performance, lets go back and look at the numbers associated with our 1.06 mm tip with a medium long facing . . . 36-24-12-6-106.

  • 36: Tells us that the facing begins very near 18 mm.
  • 24: Tells us where the resistance portion of the facing begins
  • 12: Tells us where the resistance ends and the vent begins.  We also know that the break is in between 24 and 12.
  • 6: Tells us roughly the halfway point of the vent.  A smaller number like 4 would show a straighter vent while a larger number like 7 will show a more abrupt curve.
  • 106: Tells us the tip opening.