Harold Troughton from the UK wrote me recently and asked this question:

“I recently tried a “Brilhart Ebolin Special” clt piece(The cheapest Brilhart produced) and I am almost ashamed to admit preferring it to my B40 lyre series13 Vandoren.
So I would love to hear your comments on the merits of injection Vs rod rubber mouthpieces.”

This is an interesting question and a subject of much debate among players who insist that the old mouthpieces made from solid rubber rod are superior in sound to molded rubber mouthpieces.

I do have a short answer to this question, but before I state my thoughts on that subject it might be interesting to consider the various methods that are used to produce hard rubber and acrylic mouthpieces. I will exclude metal, crystal, glass and wood mouthpieces in this post.

Let us consider the various methods of molding first, as it is the most common practice and then take a look at how mouthpieces are machined from rod rubber.

There are three types of molding processes that are used for making mouthpieces. They are:

  • Injection
  • compression
  • transfer

The following link is a brief, but very concise explanation of these methods. It is a very short article and is well worth reading before proceeding.



The J.J. Babbitt Co. of Elkhart, IN maybe the oldest continuously operating facility for making woodwind mouthpieces in the US. They are celebrating their 90th year of being in business. I have had a very good partnership with them since 1991. They make all of my Debut mouthpieces (acrylic) and all of my NOVA series mouthpieces(hard rubber). The Debut mouthpieces are made by the Injection mold process and the NOVA mouthpieces are made by the compression mold process.

My experience with the injection molded acrylic mouthpieces from Babbitt has been exceptional. The tolerances and consistency of these mouthpieces is remarkable. I do finish every single mouthpiece by hand (about 8,000 last year!), but I have a very consistent starting point which makes large production runs much simpler. Injection molding is such an accurate method that molds can be made to exact dimensions and the tolerances of the molded product are extremely fine. Also, injection molds can be very highly polished leaving a very fine finish on the mouthpiece that needs very little buffing. Babbitt puts a facing on my Debut clarinet and alto sax mouthpieces from cams that I have had custom made. No other maker is allowed to use these facing cams. The nature of acrylic is that it resists the cutting wheel extremely well and when i receive a run of 500 mouthpieces from Babbitt they are all exactly alike. The slight variation from mouthpiece to mouthpiece is only seen in the tip rail width, which i adjust as part of my final finishing. I love the sound of these mouthpieces and I doubt that anyone would guess that it was acrylic in a blind test.


The compression molded hard rubber mouthpieces are another story. Here is a look at the compression molds used by J.J. Babbit:


This method can produce some inconsistent results as I have learned over the 15 years I have been working with Babbitt. In order to have the greatest amount of control over the final product, I have developed my own core for my NOVA clarinet mouthpieces and have the mouthpieces molded slightly undersized (interior dimensions) so that in the finishing process I can file and bore them up to my desired specs. We are still refining the manufacturing process.


Hans Zinner Has been the source of my San Francisco mouthpiece blanks since 2002. Hans and Carsten Zinner are making the finest mouthpieces available at this time. Their rubber is excellent and they have very fine quality control. I believe they are using the transfer molding process which produces very consistent results. Like the compression molded mouthpieces I receive from Babbit, the warm casting must be shrunk on plugs to bring the bore to shape. This does cause some inconsistency in bore sizes and can cause a bit of irregularity in the bore walls. I get around this by having the Zinner blanks shrunk on plugs that are slightly smaller than my target dimension and boring them up to spec. I have developed a custom mouthpiece with Zinner that provides a good starting point for my extensively hand worked mouthpieces.

The Zinner mouthpiece interiors are molded in a slightly peculiar shape that leaves the top of the bore or the “crown” rather blunt shaped. This produces a very mellow sound, but lacking in upper over tones that help the mouthpiece center and project. Bringing the crown forward towards the tip also raises the throat tones and lowers the third partial (altissimo) Here is a drawing I made of a mouthpiece that shows the “bullet” shaped crown that I prefer.

I have several custom made reamers that I use to adjust the mouthpiece bore, but one in particular that only works on the crown. I have a target number for the height of the crown when I start the mouthpiece, but I might adjust that dimension slightly higher in the final sound/pitch adjustment. I will photograph some of my tools for another blog


Machining mouthpieces from rod rubber is a very expensive proposition even with the modern day benefit of CNC lathes and machinery. 50-100 years ago the machining of mouthpieces from rod rubber had to have been time consuming and complex. I am not convinced that as many of the old legendary mouthpieces were made from rod stock as many players believe. Compression molding has been around for more than 100 years and is much more conducive to large runs than machining from rod rubber would have been. I believe that Selmer is the only remaining large manufacturer still producing mouthpiece from rod rubber. Very recently Bradford Behn began machining his “Vintage” series mouthpieces from proprietary rod stock. As far as I know, the only other individual maker in the US who makes mouthpieces from rod stock is the very talented, but reclusive saxophone mouthpiece maker Fred Lambertson.

The Selmer Paris website ( http://www.selmer.fr/) has a pretty good video section on the manufacturing of their hard rubber mouthpieces which are machined from rod rubber.

You will need to navigate to the section that says “Manufacture” and then click on the “Mouthpiece” page. The process of initiating the videos is a little annoying, but you are smart and will figure it out.

Van Doren ( http://www.vandoren.fr/en/home.html) has a nice slide show of the manufacturing of their mouthpieces and reeds. Go to the home page and navigate to “Slide Show” and then to “mouthpieces”. Their mouthpieces are molded and then machined.


I have been refacing or making mouthpieces for 22 years. I have worked predominantly with molded mouthpieces, but have also had a lot of experience working with Selmer mouthpieces which are machined rod rubber. My conclusion is that there is no noticeable difference. In fact, I will go as far as to say that material has only a very small affect on the sound of a mouthpiece. And, for the most part, it is the surface finish that is the principal contribution of various materials on tone. The PRIMARY factor in the performance of a mouthpiece is design.

TONE is the quality that we ascribe to pitch. Tone is determined by the type of sound wave that is produced and by the presence or lack of harmonics. The clarinet is unique among woodwind instruments in that it acts as stopped pipe instrument (similar to the pipe organ). In this type of acoustic system the even harmonics are somewhat suppressed and the odd overtones are more dominant. It is this relative lack of even harmonics that gives the clarinet its “mellow” or ” hollow” sound as compared to other woodwind instruments. The shape and design of the clarinet bore and placement of tone holes exerts the largest influence or modification on tone, but the mouthpiece and reed as the initial generator of sound determine the amount of upper over tones that are ultimately modified by the clarinet.

The shape of the interior of the mouthpiece as well as some exterior shapes either support or reduce the harmonics produced as the reed vibrates. Clarinet mouthpieces have maximum and minimum volume parameters that will couple efficiently with the clarinet. The variance is not great, but the manner in which a maker can balance that volume between the bore and the chamber is infinite. These choices determine qualities like “free blowing”, “resistant”, ” bright”(abundant upper over tones), “dark” (lack of upper overtones), “cushion” etc. The shape of the baffle is the most influential area in how the overtones are produced, but the bore can support or reduce that result depending on its size and shape.

With so many factors interacting and exerting influence on the reed one can see that the material is a minor player in this complex system.

My conclusion as a maker and performer is that there may be a very, very small affect of mouthpiece material on tone, but it is so small as compared to design that the differences of molded rubber and rod rubber can practically be dismissed. The greatest affect that various materials have are inherent limitations that influence the workability by the artisan OR in the case of wood its changeability.

Clark W Fobes


I have a confession to make. I am a writer. I write nearly every day in my journal and find it to be the most therapeutic aspect of my life. Trust me, I will not subject the readers of this blog to the mostly mundane and often personal thoughts that I collect on those pages. These pages will be devoted primarily to my world as a mouthpiece maker and clarinetist.

Making mouthpieces is a very solitary occupation and many days I am at this for 8-10 hours. This gives me a lot of time to THINK about my craft. After more than 20 years of exploring the nuances of mouthpiece making I am still searching for the “perfect” formula. Mouthpiece making is more art than science and a “great” mouthpiece is a matter of subjectivity. However, a “good” mouthpiece can be quantified and I will certainly get into that in future blogs. My intention is to engender some discussion about the nuts and bolts activity of mouthpiece making as well as the more esoteric topic of sound and tone. I am also quite interested in the history of mouthpiece making and I would welcome any discussions on that topic.

I am fortunate to also be a very active free lance clarinetist in San Francisco, which gets me out of the shop regularly. When I am playing a run with the San Francisco Opera or playing a week with the SF Symphony, my life becomes hectic – nearly schizophrenic – in the attempt to keep up on the business AND practice and make rehearsals and concerts. But, this is the life I have developed in my beloved city of San Francisco and I would not trade it for any other. I would like to offer my insights as a performer here as well.

A further confession – I am a wannabe artist. My close friends know about my love of art and my recent ( 3 years ago) enrollment in classes for figure drawing at SF City College. I am now in a weekly drawing group that meets at the John Grunewald print studio on Plum Street in San Francisco. I am fortunate to be the sole amateur among a group of very accomplished artists. While the making of music feeds my soul and mouthpiece making feeds ME, it is this new adventure of drawing from the figure that truly satisfies my urge towards artistic creativity. Here is a self portrait from last December.

Clark at age 54

Clark at age 54

It is 5am PST and I must try to get some sleep before launching into another full day of mouthpiece making. Currently I am working on orders for MUNCY WINDS, Fredich H. Weiner and Woodwind & Brasswind. TOO MUCH TO DO!!