MOUTHPIECES
The design of a French Horn mouthpiece has always been of intense interest to the player because this single component can easily be altered to effect changes in the sound and playing characteristics of a horn. The temptation to file, bore, sand, bend, grind or cut in order to make it better has been the ruination of many otherwise good mouthpiece designs, but sometimes improvement occurs in spite of everything.
At Lawson's studies were made using a professional horn section and a divisible mouthpiece, whereby its four components: rim, cup, throat and backbore could be individually changed. Since there are thousands of combinations possible from this kit it was difficult for players to analyze subtle musical differences. In 1968 there was no objective method for reducing the awesome number of combinations.
Another study was made to record the dimensions of hundreds of mouthpieces and average them. This yielded guidelines that a mouthpiece maker could use to develop designs acceptable even to the horn player of today who is performing a wide variety of music.
Presently, with the aid of computer technology, electronic means exist which simulate an instrument being played. This output contains a variety of objective information, previously expressed subjectively by the players. This information includes an analysis of: intonation, tone color, startup or response time, ease of playing in the different registers, uneven response, slurring, sound radiation, plus other qualities. Unexpectedly, the musicians' collaboration with the designer is even more important than before as the players' goals are diverse and need to be defined.
The mouthpiece is tuned on a lathe from any material that is machinable to dimensions of very close tolerances. Precision is important as a musician can feel changes in the acoustics of his instrument as a result of mouthpiece variances of a thousandth of an inch (.001"). Brass or plastics are the materials of choice. Brass mouthpieces are generally plated silver or gold. Some players prefer to use a bare metal rim because it oxidizes to a rough finish which gives a feeling of security. This is not recommended because of the danger of allergic reaction or even in severe cases, metal poisoning.
Players may be classified in two categories, those that use a dry embouchure or those that prefer a wet embouchure. The rim surface can greatly influence performance. A rough surface, such as a rim which has been silver plated is best for dry embouchure players who need extra friction for a good grip. Gold plate provides the slippery surface desired by wet embouchure players.
People with allergies to metal are recommended to use plastic rims. These materials vary, so careful selection of the right plastic is important. Some plastics are very brittle and are easily cracked or broken. Other irritate sensitive lips or are very slippery. Once the right plastic formula is found, the concerned player would do well to obtain a sample length so that future rims could be made without an aggravating search for the same material.
The most commonly plated surfaces are silver or gold. These two elements are relatively soft and wear in a gradual manner so that there is never a sharp edge where the brass metal is exposed. Once the plating has worn through, the mouthpiece should be refinished because the base metal will etch. Pits or scars will result if left unplated too long. Hard plates such as nickel or chromium are cheap but tend to chip leaving razor sharp edges that can seriously injure a lip.
RIM DIMENSIONS
In order to insure even wear of the rim and shank, the mouthpiece should be inserted into the horn's mouthpipe differently every time. The size and shape of the rim are extremely important to each player because of the direct physical contact. The dimensions of the rim are:
1. Outside diameter - may vary from .920" - 1.00" plus.
2. Curve depth - outside and inside the cup - this measurement with the grip, peak, and outside diameters, determines the rim contour.
3. Rim contour -
Outside contour - To those that use an ansetz (set on) embouchure the outside shape of the rim is relatively unimportant but an einsetz (set in) embouchure is very sensitive to the outside contour. Some player's lips shift from ansetz to einsetz as they pass through different registers. This is especially noticeable in a player that moves the lower jaw out for low notes and rolls the lower lip around the rim edge. In this case a rounded outer contour of the rim will produce smoother slurs, particularly between lower open harmonics. There may be some loss of endurance due to the narrower front face of the rim, but the ability of the player to compensate with a build up of strength soon returns endurance to normal and the trade-off in having better flexibility is often worthwhile.
Face contour - There are four popular rim face contours - oval, wide cushion, reverse peak and round. Selection of the proper shape depends on a person's teeth, oral cavity, shape and thickness of the lips and how the rim feels and performs.
a. A round contour offers good flexibility and medium endurance.
b. A cushion contour enhances endurance because the rim is wide, but limits flexibility.
c. A reverse peak contour is a narrow rim that feels wide across the grip and conforms well to certain types of tooth structure.
d. A oval rim is a general purpose type which offers average endurance, flexibility and clarity of attack. The player would do well to use empirical methods in the selection of a rim contour.
4. Peak diameter - the measurement which is obtained if a rim is placed face down on a glass plate smeared with some sort of colored material so that a mark will appear on the face of the rim. This is the outermost part of the rim contour that contacts the lips and it have a very narrow measurement range averaging from .800" to .835". The rest of the contour is built around this diameter.
5. Grip diameter - a vague yet extremely important dimension that must be determined primarily relying on experience. The grip controls slurring (flexibility) and clarity of attack. A rounded grip allows the lips to vary tight to loose easily, a sharp grip restricts the lips but allows a more clear, crisp attack. Grip diameters generally varyin a narrow measurement range from .690" to .705" but there are many exceptions. The grip diameter is a very difficult measurement to make. Some players use dimes, a bus token or other methods to record their grip diameter. This is accomplished simply by noting how deep the coin drops into the cup vertically. If a person finds amouthpiece that feels good, then that grip can be used as a reference for comparison with further measurements or other mouthpieces.
CUP DIMENSIONS
1. Cup threads - should match the rim threads.
2. Joint diameter of the rim - determine the width of the cup at the joint. This measurement varies in a very small range of .660" - .670". Variations influence the ease of playing or efficiency of the horn in different registers.
3. Cup volume - the most important acoustic variable of a mouthpiece which can now be optimized electronically for any given length of horn.
4. Cup shape - a major factor in determining the acoustics of the mouthpiece. Of the three styles of cup: convex, straight, and concave tapers, the latter has proven to be most efficient and best suited to today's requirements. The curve of the side of the cup can be altered to create different effects.
5. Throat size - can be controlled by varying the drill size of the hole and the total length of the cup This is the one mouthpiece dimension easily altered but can only be enlarged. If the throat is to be opened, it should be drilled one number size at a time. The average throat size of a French Horn mouthpiece is a No. 11 (.191"). The most accurate way to size a throat is to use a reamer after drilling the hole undersize. This ensures a uniform, consistent bore. For a given diameter of hole, a long throat will give more resistance than a short throat and will play with a stronger response in the mid-range of the instrument at the expense of the high-range. Obviously, a careful balance must be determined for the intended player.
6. Backbore - this inside taper is made with a reamer and its size and shape can influence the ease of playing in the different registers and how much the horn 'locks up' to a particular range of harmonics.
7. Outside shank taper - determines the depth of the mouthpiece penetration and fit into the mouthpipe. American mouthpieces have a Morse 0 taper (approx. 3 degrees). The dimensions of this taper should be carefully maintained because poor mouthpiece fit can drastically alter an instrument's performance.
For a more in depth look at our mouthpiece designs and options, ask for our publication "An Explanation of Mouthpieces" or Vincent Bach's superb article written decades ago entitled "Search For The Perfect Mouthpiece".