Sax Mouthpiece Acoustics

Saxophone Mouthpiece Acoustics

This is a plain-English overview of the acoustical physics of saxophone mouthpiece designs, written especially for saxophonists. It will contradict the choices made, and convictions held, by many players.  It is not my intention to offend anyone; to the contrary,  I offer information to simplify your lives, empowering you to greater artistic heights.  Saxophone playing is an incredibly demanding art form, and since you're capable of moving people's emotions, and empowering their dreams, by moving air through a piece of metal tubing, only you can decide how best to do so.  So if you find this helpful, great!  And if not, great!

Okay, here we go.


Chamber size

As we all know, the saxophone is a conical bore instrument.  If we were to straighten out the horn's lovely curves, including the flare of the bell, the saxophone would look like Fig 1 below.  Note the cone is not complete; the small end is cut off, so that we may affix a mouthpiece.

However, if, instead of cutting off the small end to affix the mouthpiece, we were to continue the cone's straight lines to the point where they meet, we've added a smaller, but proportionally identical, imaginary cone at the small end.  This is represented by the shaded area in Fig 2.  



We can measure the volume displacement (the amount of volume contained) of any such cones.  And when we create sound by moving air through such a tube, scientists call this volume displacement "acoustical mass."

If we measure the acoustical mass of the shaded area in Fig 2, what we have done is calculate the correct size of the mouthpiece chamber.  You know who said so?  Adolphe Sax, that's who.

In order to follow the laws of acoustical physics, saxophone mouthpieces need to have a chamber of this size acoustical mass.  Generally speaking, the only mouthpieces that actually adhere to this rule are "traditional" designs, such as Links on tenor and Meyers on alto, or the whole range of vintage Selmer Soloists.


Chamber shape

So far, we've only discussed the size of the acoustical mass of mouthpieces.  But another factor is design geometry--the shape of the acoustical mass.  The appropriate size of acoustical mass can come in a variety of shapes, and each will have an impact on how the mouthpiece plays.  For example, most of us are familiar with two vintage Link designs: the Tone Master, and the Super Tone Master.  Both are of correct sized acoustical mass, however, the Tone Master is shorter and fatter, while the Super Tone Master is longer and thinner.  Most would agree that the Super plays more efficiently, with more ease, projection, and better response.  Same size, different shapes.


Common problems

We're all familiar with simple aerodynamic design modifications, such as high baffles.  Baffles focus the air into higher pressure, therefore speeding it up, resulting in a brighter sound.

The problem with high baffles is that, unless the designer has compensated for this shape by adjusting (increasing) the acoustical mass size, we have a mouthpiece that does not follow the fundamentals of physics.  Alas, I'm unaware of any high baffled mouthpieces that indeed have such compensation for size of acoustical mass.  Hollywood Dukoffs come the closest.

When using a high baffled mouthpiece, the player has to compensate for a number of undesirable consequences. 

Pitch and timbre become uneven over the range of the instrument.  Upper register notes play sharp, while lower register notes play flat.  Timbre is markedly different between notes, even adjacent ones, and is especially exaggerated between open C# and 4th line D. The fundamental is less present; brightness gives the player the impression that he is playing louder, but in reality, the higher harmonics drop off very quickly as the listener moves further away from the player; bass waves are non-directional, so a stronger presence of fundamental projects better to the back of a room. Low register response becomes difficult unless approached explosively, leading to what I call "playing with a limp," i.e., favoring one side of the horn over the other.  (Ever hear a smooth jazz saxophonist play a fat, lush subtone in the low register?  Neither have I.) 

Some of us play baffled mouthpieces, with stunning results.  But if you do, you're compensating for the compromised physics of your mouthpiece.  It's almost certainly second nature by now, and if you don't have any nagging difficulties with any of the issues discussed above, and if you're satisfied with at least two thirds of the reeds you buy, then you have no reason to look further.

But if I've described issues that are bugging you, now you know where to start looking.


Summary

Your equipment does one of two things: it either gets in your way, or gets out of your way.  Personally, I don't like having to outsmart my gear.  If I have to think about how to get a note to respond, my brain is functioning on a lower, technical level.  I like to be in a higher, artistic consciousness when I play, and I'm betting you do too.  Eliminating undesirable variables frees up your valuable brain power, so you can concentrate on making music.  

If you currently play a high baffled mouthpiece, and are experiencing the problems described here, you may consider switching to a more traditional style of mouthpiece.  However, the transition requires sustained commitment--it's not reasonable to expect immediate results.  It often takes a month before your new sound begins to take shape, three months before you start sounding really good, and a year before it's second nature.  It's highly advisable to seek knowledgeable assitance to help you through the transition.  But once you go through the process, you'll never go back.  There's a reason that the plurality of history's great, signature saxophone sounds were created using traditional style mouthpieces!