Flex mouthpieces are made using Stomvi's proprietary Bellflex brass alloy. This alloy has extremely resonant properties and is integral to the design of Flex mouthpieces.

The VR series use a new cup and backbore balance, designed by K.O. Skinsnes. VR cups are a hybrid design, functioning like a shallow cup in being easier to play and increasing endurance, yet with their unique shape and internal volume producing the bigger sound and timbre of a deeper cup, with a rich spectrum of harmonics in the sound.

Flex mouthpieces offer different backbore choices and are available as solid shank or cut for Couplers, which allows you to adjust the gap from the end of the mouthpiece to the start of the leadpipe. The Couplers themselves must be ordered separately; please contact us at Thompson Music. Or go to bottom of page.

VR mouthpieces are available with Bach-equivalent 1, 1½, 3, 5, 7, 12, and select additional rim widths, each in the full range of cup depths. Furthermore, each rim/cup combination is available with one of the following backbores:

T2 (Tornado Backbore)
An extremely efficient and free-blowing backbore with a huge, tornado-like sound. Developed in conjunction with Jim Manley, this is a great backbore for players who use efficient, smaller quantities of air, but still desire a big sound.

Vs (Speed of Sound Backbore)
The Speed of Sound Backbore (Vs) is a very efficient and open backbore. Great for players who want to "back off" and get more sound for less work.

J6 (Command & Control Backbore)
More centered and easier to play than the Vs. If you like the Vs, you'll love the J6!

C4 (Explosive Backbore)
An extremely efficient and free-blowing backbore with a huge, explosive sound. Developed in conjunction with Lynn NIcholson, this backbore is great for players who like to push a lot of air in the upper register. It requires shortening the mouthpiece in order to maintain the proper resonance frequency, or balance.

#5 (Symphonic Backbore)
Extremely well in tune backbore that works well for orchestral players and those who push a lot of air into the horn.

L4 (Lyric Backbore)
The L4 is a great backbore for classical playing, especially for C Trumpet. It requires shortening the mouthpiece in order to maintain the proper resonance frequency, or balance.

All Flex Mouthpieces are made using a combination of CNC machining and hand balancing. Choosing the correct mouthpiece is a very personal endeavor; feel free to contact us with any questions or concerns and we'll do our best to help you in your quest.

Models are listed on this page by cup size, from smallest to widest, followed by Schilke model sizes, and Custom designs

Used Stomvi Mouthpieces

Stomvi Couplers
$20.00
Flex Couplers Defined: The Flex Coupler acts as an acoustic coupling mechanism between the trumpet receiver and mouthpiece and allows you to adjust the amount of penetration of your mouthpiece into your trumpet. he space between the end of the mouthpiece and the start of the leadpipe (the annulus or gap) is critical when fine tuning your set-up and can make or break a how a mouthpiece plays. Adjusting the gap is the final stage of fine tuning your equipment to perform the way you like. Our couplers are made with our proprietary Bell Flex alloy used on our Flex Mouthpieces and our high end trumpet bells. Our Couplers also have a bit of extra mass where the coupler contacts the middle of the mouthpiece shank which also improves their playability and sound. By using the couplers to find the gap that works best for you on your horn, you guarantee the best sound, slotting, intonation, and feel from your mouthpiece. New Proprietary Brass Alloy Flex couplers are made using our proprietary Bellflex brass alloy. This alloy has extremely resonant properties and is also used in the design of our high-end trumpet bells, as well as our Flex mouthpieces. Which Size do I need? There is some confusion among the trumpet community about which is the correct gap. The correct gap is the one that is gives you the playing characteristics that you want, and the only way to find the correct gap is by experimentation. Each half size results in a 1/32” difference in gap with the larger number representing less gap. Most mouthpieces manufacturers have a shank size between 4 and 6. Feel free to contact us if you need guidance on which coupler size to start with.