This website contains lots of detailed information about the Asymmetric mouthpiece. But not all trumpet players have the time or desire to look at the details. This page has been included to give trumpet players a quick, single page explanation of the Asymmetric design, and a concise explanation of “how it works”.
In June of 1942 Hayward W. Henderson (a researcher at Peabody Conservatory of Music in Baltimore) reported in the Journal of the Acoustical Society of America, that contrary to popular belief, “experiments seem to give conclusive proof that trumpet tones are originated by the upper lip vibrating as a single reed against a relatively fixed body, i.e. the lower lip.---The lower lip, not being an entirely fixed body, is forced into a limited vibration --- but its main functions are to provide something against which the upper lip can vibrate and to control its vibration rate (pitch).” I have worked as a referee for several physics journals over the years. I looked at Henderson’s work and found it to be correct and credible. Others (the peers on his review committee) have examined his work and have come to the same conclusion. This work is assumed, therefore, to be correct in all of the following discussion. What this means for the trumpet player is that as the top lip is vibrating (opening and closing) the bottom lip is pushing up against the top lip and controlling the pitch. The harder the push (the greater the between-lip pressure), the higher the pitch.
To understand the Asymmetric design let us first imagine a trumpet player playing a high C (the limit of his range dictated by his lip and face musculature), using a conventional, (symmetric) glass trumpet mouthpiece (glass so we could see inside of the cup). If we focus our attention on this player’s lips inside of the cup we can see that part of the lower lip (which we will call the segment) is inside of the cup rim. For convenience we will model this segment as a generic solid having six faces, front, back, two sides, top and bottom, that define its volume; much like a cube or other similarly defined space. If we think about this surface of this lip segment we can see also that it tends to be rigidly held in place (can’t move) by the lower teeth against its back surface, and the mouthpiece rim holding its sides and bottom surfaces. This leaves two surfaces, top and front, as yet not discussed. We therefore also note that the top surface of this segment is pressing (but not rigidly constrained) up, against the top lip to control and sustain the high C pitch (re. Henderson). The front surface of this segment is not being constrained at all. It is pressing against nothing and so, is free to bulge slightly (due to the pressure required to obtain an air seal) into the cup. This front surface is, therefore, contributing nothing constructive to the process. Now, let’s look at the same player playing a glass Asymmetric mouthpiece. Here, we see a fundamental difference between the mouthpieces.
With the Asymmetric, the bottom lip segment is also identically constrained on its sides, bottom, top and back surfaces as just described. But it is also rigidly constrained on its front side by the metal in the Asymmetric cup. Therefore, there can be no lower lip bulge into the mouthpiece. Thus, for the same amount of playing effort, the lip segment experiences an additional upward pressure component with the Asymmetric mouthpiece, It therefore pushes harder (in all directions including upward, toward the top lip), and in so doing produces a higher pitched note than the conventional mouthpiece. Herein lies a subtlety. To repeat, all surfaces of this segment are rigidly constrained (can’t move) except, in both cases, the top one. The segment therefore tends to bulge UP (the only direction available for it to move) and press harder against the top lip, thus producing a pitch that is much higher than high C for the same effort expended. This (Asymmetric) player now has a higher range. The segment is physically a tiny bit of lip tissue (“balloon”) that is filled with blood. It functions like a regular balloon filed with water. Because water and blood are both incompressible, if you squeeze either balloon in one place, it will bulge in another. So, we can say that the bulge has been transformed from a useless forward bulge into a prolific upward bulge. This may seem to be a small effect. But for trumpet players, it turns out to be worth about half an octave in high range, depending on the player.
Improved Endurance is also a byproduct of the Asymmetric design. For trumpet players, because the left arm force used in playing the trumpet is distributed over a bigger area, (which includes the wider asymmetric rim of the Asymmetric, the pressure (defined as force divided by area) is decreased by about half. Endurance is seen by many users to double.
The Asymmetric mouthpiece is a landmark engineering achievement and a giant step forward in mouthpiece design. It represents my best effort; I can not see a more elegant way to achieve added range (between- lip pressures) than by exploiting a design flaw (unrestricted lower lip), as was done here. Also, by identifying the flaw and turning it into an advantage to enable greater range, some other beneficial byproducts are also attained. Easier high register, increased endurance and unrestricted sound quality (no longer must high range require shallow cups), to name a few, are now distinct realities. The Asymmetric mouthpiece design doesn’t interfere with traditional design elements like backbore and cup shape, but instead, enhances the performance of all brass instruments. It should stand for years to come, as a model of efficient mouthpiece design. And, It would appear that the brass player’s two most difficult, fundamental problems (difficulty with range and endurance), that have defied mouthpiece designers and players for over a hundred years, may finally have a common, viable solution. Mouthpiece makers the world over are invited to embrace this cutting edge technology and improve on it, if they can.