Mouthpiece throat size

Q: Should I have the throat of my mouthpiece enlarged?


Editor’s note: What follows below, at least until the next horizontal line, was provided by Scott Laskey, and edited by me. Scott Laskey was the mouthpiece maker at Schilke for over twenty years and one of the nation’s foremost experts in mouthpiece design and performance. He currently makes his own line of fine mouthpieces for The Laskey Company. He is also a trumpet performer and teacher and a former student of Renold Schilke. I am exceedingly grateful for his time, effort, and assistance in preparation of this.


Historical Background

Around the turn of the century, when the instrument of choice was the cornet, mouthpieces having throat sizes ranging from 14 to 18 were not uncommon. As trumpet playing began to become more popular and more influential later in the century, the larger throats were still common, but started to get smaller and 18 to 22 became the normal sizes for the orchestral player and 20 to 24 for the jazz player.

Many of the mouthpieces were imported from Germany and made by the Schmidt company (the originator of the Schmidt backbore). Mouthpieces made by manufacturers in the United States had not yet caught on with the better players and what mouthpieces were made domestically were generally copies of Schmidt’s anyway.

However, at that time, the inside diameters of the mouthpieces were quite small. The Heim and the Llewellen mouthpieces were being used by players in large symphony orchestras. These compare in diameter to the current Bach 7C to 10 1/2 C size. But these were still copies of Schmidt mouthpieces.

Vincent Bach was the first American manufacturer to actually make mouthpieces of a consistent nature in a quantity and at a price that were affordable for both students and amateurs. According to those who knew him, Bach employed a standard throat size for manufacturing purposes. To make all the different models in various throat sizes would be a nightmare both in terms of inventory and manufacturing. Accordingly, Bach reduced the standard throat size of his mouthpieces to the current size #27 (0.144 inches) with the belief that players would then adjust the throat size of their mouthpieces to suit their own playing style and needs, meaning that he expected players to open the throat of their own mouthpieces.

A former employee of Bach once told me that when mouthpiece sales were down, he would then “as a keepsake of their visit to the Bach factory” give people the tool we commonly refer to as a hand reamer, or jeweler’s reamer (five, four, or three sided English pin broach).

As late as the 30’s and into the 40’s mouthpiece sizes did not appreciably change or increase. I believe that Harry Glanz played a Bach 6C through out his career in New York. Adolph Herseth won his job in Chicago playing a Bach 7B. While some say Georges Mager played a very large diameter (as offered in the Schilke model 20D2D), I have been told by others that the diameter was actually much smaller in the early part of his career and that he went larger only later.

It was in the 50’s that players began to move to mouthpieces with larger inside diameters. Herseth told me that he went large as a way of avoiding the scar tissue he had from the automobile accident he had in the early 50’s which severely injured his chops. For what ever reason, orchestral players in Boston and New York also began to go larger as well. Perhaps it was due to the size of orchestras getting larger and louder. I am not sure.

Commercial players and Jazz players seemed to have stayed with the same sizes as before, or if going larger, not by very much.

But through all of this, the standard for throat sizes remained at #27, with the few exceptions noted below.


What happens when I enlarge the throat of my mouthpiece?

For many, enlarging the throat is synonymous with “free-er blowing”. I believe that while the throat is the only component in the mouthpiece which has direct control over how much air actually passes through the mouthpiece, however, I feel that other factors contribute even more to the perception of air flow. For example, rim contour controls how freely the lip vibrates and when lip vibration is less restricted, we perceive the mouthpiece to be more “free blowing”. Also, mouthpiece mass also effects the perception of resistance, as both Bach, in the Megatone line, and Monette automatically increase the size of the throats of their heavyweight mouthpieces to compensate for the increased perception of resistance caused by the mass of the mouthpiece. The exterior mass of the mouthpiece cannot effect the actual quantity of air passing through the mouthpiece, but it does effect the perception of the player. As an aside, it has been my observation that “feel” is used too frequently in determining what is needed when choosing the instrument we play or the mouthpiece alterations we make. Sound is a much better judge in helping us determine the necessary changes in our equipment. While we may initially not like the feel of something, it is amazing how our perception of a “feel” changes when the sound and performance are improved.

In any event, it is clear that opening the mouthpiece throat does allow the player to put a greater volume of air through the mouthpiece. The benefits of this are:

  • The musician is able to play louder before the sound begins to get “edgy”. I believe it is for this reason that most orchestral musicians use much larger throats today. Their need to play incredibly loud without distortion is essential to their job.
  • The sound takes on a thicker, darker core. While I know that this is a very abstract way of describing the results, it is the best and only way I know of describing the change.
  • I also feel that the ability to play softly is increased with the larger throat. While it is probably less efficient, it is the inefficiency that makes this so. We use more air while still playing at soft volumes, making the playing of the trumpet less treacherous in such passages.
  • Using a larger throat can be beneficial to a student, especially if his or her focus is on how they sound as opposed to how they feel when they play. If they focus on how they sound, the larger throat will help the student to develop the volume and the constant air flow we strive to teach. The air flow will become a natural process with little need to guide or consciously try to adjust the physical technique. Conversely, if the student cannot pick up on the difference in sound and emulate it by producing a better flow of air, playing will become more difficult and his or her sound will not be supported.

With a larger throat, however, there is a need to support the air flow to a much greater degree than with a smaller throat. If the player doesn’t support the air flow sufficiently or opens the throat to a point where he or she can no longer support adequately the air flow, the player will produce a very thin and weak sound with a lack of overtones and without a focus or core to the sound. In addition, the player fatigues more quickly and range diminishes.


Does enlarging the bore affect intonation?

Everything in a mouthpiece affects everything in the mouthpiece. Changing rim contour affects intonation. Changing mass displacement affects intonation. Changing backbores affect intonation, and, yes, changing throat sizes affects intonation. But the specific effect of the change is relative to the backbore, throat size, throat length, inside diameter, outside diameter, cup shape, and cup volume of the mouthpiece.

Any change in intonation, however, will be as much a function of throat shape as it is throat size. A tapered throat is where the throat dimension is a single point in either a constant or dual taper; a cylindrical throat is where the throat is actually a cylinder in the mouthpiece having the same width over a certain length. Some throats are made of parts of each. Opening the throat with a drill, without adjusting for any taper in the throat, will turn a tapered throat into a cylindrical one. As a general rule, the longer the cylindrical section in the throat, the more focus or center to the sound, but the more it tends to condense or shrink the octaves, meaning the lower register goes sharp and the upper register becomes flat. As the cylinder is shortened (either from the backbore or the cup side) the octaves then augment or spread apart–all relative to the other aspects that makeup the mouthpiece.


Does enlarging the bore effect tonal color?

I tend to think that altering the throat alters the tone color (usually darker) and altering the backbore alters the (again abstract term) shape of the sound.

The backbore, in my opinion, is like the hand sprinkler we put on the end of a water hose. We can control the shape of the spray and the disbursement of the water by changing the settings on the sprinkler, like we can control tonal color by altering the backbore.

The throat of the mouthpiece is more like the size of the hose itself. A smaller diameter hose will allow a smaller amount of water to pass through it. A larger hose will allow more water to flow through. In our application, more air will flow through the larger throat which will allow more overtones to become present in our sound and give us a thicker, denser quality to our sound.

But still, the overriding factor is how much volume of air is being used and the velocity of air being used to set everything into motion.


Editor’s Note: Jim Donaldson alone is responsible for the following:


How big are these holes anyway?

The drill size number is a standard machine tool designation with the larger numbers (#28) being smaller and the smaller numbers (#13) being large. The measurement is in decimal fractions of an inch (i.e., ten-thousandths of an inch), so the #28 is 1405/10000 of an inch. For a chart which includes fractions and millimeters, go here.


For reference:

  • #28 is standard for Jet-tone and some Purviance and Reeves pieces;
  • #27 is standard for most manufacturers;
  • #26 is standard for Schilke, except for the shallow cup pieces, which are #27;
  • #23 is standard for the Claude Gordon mouthpieces, except for the Personal Model which is a #22;
  • #18 is standard for the Flip Oakes Wild Thing cornet mouthpieces;
  • #13 is standard for the Oakes flugel mouthpiece, which is the biggest production bore I could find.

Monette mouthpieces all seem to have larger than standard throats though the specifications are not published.

Endsley Brass sells a mouthpiece gauge to determine the throat size of trumpet mouthpieces from #18 – #28. Because drill sizes in massed produced mouthpieces are often between exact dimensions, the gauge which is constructed to .001 tolerance will reveal this as well. It is constructed of hard aluminum and is supplied with a chart listing drill sizes in both English and metric readings. It costs $20 and is available directly from Endsley or from Giardinelli.


How do I enlarge my mouthpiece throat?

Resist the temptation to throw your mouthpiece in your bench vice, get out the Black & Decker and an 1/8th drill bit, fire it up, and start sticking it in the mouthpiece throat. The proper way to do this is with a lathe and reamer. Otherwise, he or she will leave drill marks in the throat (which will cause turbulence, i.e., resistance), and end up with throats cut at odd angles and in oval shapes, all of which adds several new variables that will negatively effect performance. Don’t be a cheap-skate with your mouthpieces, take them to a qualified mouthpiece maker or repair technician who has the proper tools, knowledge, and experience to do the job correctly. The cost is modest. For example, if you live near the Schilke shop, it’ll cost you $3. Other shops are comparably priced, I’d bet. You may wish to have the throat number stamped on the shank so you know which is which.


How large should I enlarge the throat?

Who knows what will work best for you? The best advice is to do it one size at a time. Open your #27 to a #26, play on it a while (more than 10 minutes in the shop), then perhaps open it to a #25, and play it is some more, and so on. When you get to the point that it is perfect, stop. Or when you get to the point that you liked it best the way it was before you opened it last, buy another and have it opened that much.

Some folks find doing this in descending pairs is more instructive, i.e., starting, say, with two Schilke 14s with standard #26 throats, open one to #25 and compare it to the standard; if you prefer the #25; have the standard one opened to #24, then compare; if that is better than the #25 and you think even more open would be even better, then take the #25 one and have it opened to #23. If you find that that is too big, you still have the other one at #24, so play it and make beautiful music. Try to sell the one with the #23 or hold on to it; after you have played the #24 one for a year or two, the #23 may be just the ticket. Or maybe not. Sell it then.

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