3 Inherent Problems with Gap Formulas and Studies

A lot of great, in depth work has been done about the trumpet mouthpiece gap. Unfortunately, many of the frequently cited formulas and studies on the gap have inherent problems that create erroneous results, which when relied on, will deter trumpet players from achieving optimum results with their equipment. I’ll address three of these inherent problems here.

Problem #1 – Failure to Take The Player Into Consideration

As we have written about previously, a proper study on the gap must include all three essential elements of the system – the trumpet, the mouthpiece, and the player. Having helped thousands of players through the years to fine tune their gap, we have no doubt that the player is the most important variable of the Player-Trumpet-Mouthpiece System.

No gap formula or theory to date has been able to calculate what a player feels, and most importantly, what a player prefers to feel. Yes, there are certain generalizations about the gap and ranges of sizes that many players fall into.

Relying on these generalizations is as silly as blindly buying a men’s size 9 or 10 shoe because that’s the range of shoe sizes most commonly sold, even though you are a woman who wears a woman’s size 8.

Relating this back to the gap:

Find the gap that plays the best for you, not what someone else told you should feel the best for you.

Problem #2 – Failure to Take Changes in the Equipment Into Consideration

We know that a change in the gap changes the acoustical impedance in the Player-
Trumpet-Mouthpiece System. It is also well settled that there are thousands of other variables in the mouthpiece and trumpet that can change the acoustical impedance in the System.

Due to the nature and limitations of mouthpiece and instrument manufacturing, it is impossible to consider every variable that affects acoustical impedance. Put another way, it is impossible to isolate and therefore calculate, what the gap should be considering every variable.

The gap formulas and theories sometimes attempt, but do not succeed in addressing every variable in the equipment and therefore cannot predict anything with any consistency.

Problem #3 – Failure to Take The Environment Into Consideration

While the first two problems on this list are the most important inherent problems in any gap formula or theory, the third problem — considering the environment — is worthy of a mention.

For argument’s sake, let’s say that we can calculate an optimal gap considering the player, the mouthpiece, and the trumpet. We know that the acoustical properties of the environment you are playing in can affect the acoustic impedance you feel as a performer.

Playing outside in hot, humid weather and then moving inside a air-conditioned, dry, acoustically “stuffy” room can drastically change the acoustical impedance, and in turn, what you feel.

In today’s musical climate, you could easily find yourself in a stuffy recording study, then in a huge, open cathedral. While most players would not think to adjust the gap in these situations, a significant minority of players have fine-tuned the gap to their varying situations.

Learn More About the Gap

History of the Mouthpiece Gap & Bob Reeves Sleeve System: Part I

Carroll Purviance, Mouthpiece Maker
Mouthpiece maker Carroll Purviance.

The Early Years

The first time I learned about the gap was on a visit to Elden Benge’s Burbank shop. He explained to me how he made his trumpet play better in combination with Bach mouthpieces, which were popular at the time. He moved the receiver on the horn back until it played the way he liked it. Benge’s goal was to find the gap that worked best, not find out what the gap was “supposed to be.”

When I went to work for Carroll Purviance in 1961 he had two shank sizes for his mouthpieces, his standard, and a smaller B shank. Purviance discovered that for some setups, one shank would play better than the other.

During that same period I was studying trumpet with John Clyman, who had his own theories about the gap. He believed that there should be at least some gap between the mouthpiece and leadpipe. This was contrary to another theory that suggested that very little, or no gap was best. Clyman would push me to work on mouthpiece projects for him in exchange for the lessons he gave me. He then bought my first lathe (which I still use today) and I opened  up my own shop in the back of my Mother’s house.

Opening Up Shop

In April of 1968 I opened my shop in Hollywood, California and was fortunate to attract the top brass players in the world. My shop was a sandbox where we would try all the ideas we had on our minds. Some turned out good, some bad, but it was fun and a unique learning experience.

Bob Reeves Trumpet Mouthpiece with Sleeves
A Bob Reeves trumpet mouthpiece cut for sleeves with sleeves.

My experiences with Benge, Purviance, and Clyman, along with my day-to-day observations of players made me realize how crucial the gap really is.  Discovering the proper gap was a time consuming process, requiring a lot of salvage work on customers’ mouthpieces. I would think that the gap should be increased so I soldered a new shank on the mouthpiece, only to find out that it should be smaller and had to file down the shank, or vice-versa.

The Bob Reeves Sleeve System

It only took a few times of going through this painstaking process to figure out that there must be a better way. This planted the seed that grew into my adjustable sleeve system. Thanks to my friends Bill Cardwell and Don Macintosh,  in 1974 I was granted my first patent for the sleeve system.

Check back for Part II of this series!

Click here to learn more about the Bob Reeves Sleeves System.

New Dealer – BMmusic in Korea

We would like to welcome our newest dealer to the Bob Reeves Brass family – BMmusic in Korea. BMmusic is a trumpet and brass specialty store that provides its customers with unmatched customer service and the highest quality products for brass musicians. If you are in Korea and want to try a Bob Reeves Mouthpiece, contact them today!

1818, Sindang-dong
Dalseo-gu, 704-922
South Korea
Phone: 82-05-3584-4879

You can find a list of all of the Bob Reeves Brass U.S. and International Dealers here.


New Bob Reeves Dealer – Saied Music Company

Saied Music Company - Tulsa Store

We’d like to welcome our newest dealer to the Bob Reeves Brass Mouthpiece family – Saied Music Company. The good folks at Saied Music have been serving musicians since 1946 and have five locations covering Oklahoma and Arkansas. They are not only knowledgeable about the products they sell, but also very friendly! We invite you to visit them if you are in the area, or if not, you can always visit them online at www.saiedmusic.com.

Here is the contact information for their stores, which is also available on our Dealers Page:

3259 S. Yale Ave
Tulsa, OK 74135
(918) 742-5541


9320 E 71st Street
Tulsa, OK 74133
(918) 252-5541


4300 Rogers Ave Ste. 55
Ft. Smith, AR 72903
(479) 783-3050


2880 North Point Circle
Fayetteville, AR 72704
(479) 571-2400


2921 Lakewood Village Dr.
North Little Rock, AR 72116
(501) 758-0200

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Happy Valve Alignment Customer!

Alex Cabrera playing his Kanstul Flugelhorn
Alex Cabrera of Infinity Music playing his Kanstul Flugelhorn

Here’s an email we received from Alex Cabrera of Infinity Music a few days after he visited the shop and got a Bob Reeves Valve Alignment:


Thank you so much for spending time with me and getting the alignment straight on my Benge. I started a three night gig at the casino and must say last night was the first night with the new adjustments you made. I must admit that it was free blowing in the upper and lower register and I had enough chops at the end of the 4 set gig to do another 4 set gig. I knowyou said that the horn was way out of whack or if I used your words “YOU DON’T KNOW THIS HORN”. You are absolutely correct!! I did not know it but I must admit I am getting to know it and it is AWESOME. Thank you once againfor setting this horn up correctly. I am sending you my Kanstul Copper bell Flugelhorn next. I have one more trumpet to do the following month then we can start the talks on a custom mouthpiece.

Alex Cabrera
Infinity Music

You can read more about the valve alignment on our web site, or feel free to give us a call or email for more information.

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Bob Reeves Brass – Holiday Hours

Happy holidays to you from everyone here at Bob Reeves Brass. As the year draws to a close, we are thankful to all of our customers & dealers for giving us the opportunity to work with you, and look forward to an even better 2011 filled with new and exciting things!

Holiday Closures

If you are trying to reach us, please note that we will be closed from Thursday, December 23rd through Sunday, January 2nd. We will be open for business as usual on Monday, January 3rd.


Also, we are booked up on alignment appointments and custom work for the rest of the year. We are already booking appointments in January, so if you have something you want done, you’ll want to give us a call or email.


We are currently back-ordered on mouthpieces through the end of the year. That means orders placed now will not ship until January. We do have a limited stock of mouthpieces on the shelf, so if the particular model you are looking for is in stock we can ship right away.

Happy Thanksgiving! Shop Closed Thursday & Friday

Happy Thanksgiving! We will be celebrating with our friends and family this year, so the shop will be closed on Thursday & Friday November 25-26. We will back in the shop for business as usual on Monday.

Thank you for giving us the opportunity to keep making mouthpieces and performing valve alignments year after year (for 41+ years now!).

All the best,

Bob & the Staff

Automotive X-Prize

Illuminati Motor Works Team - Courtesy of Illuminatimotorworks.org

We talk to many trumpet players every day, but not everyone we talk to plays trumpet for a living (in fact most do not). Last week I had the pleasure to talk with Thomas Pasko who has two passions, trumpet and cars. On the trumpet side of things he plays a Bach mouthpiece for most stuff and then moves to a Bob Reeves 42/M when he needs a little more efficiency. However, we come to find out that he was just back from competing in the Automotive X-Prize, where his team the Illuminati Motor Works  just took 2nd place, and probably should have won the $5 million prize.

It’s great to talk with people who are so passionate about what they do.  Do yourself a favor and check out their web site at http://illuminatimotorworks.org/.