Alpha Angle

trumpet.trader · Veteran Member Joined: 02 Jul 2017 Posts: 200

Okay, I’ve seen this term used a lot. I’ve tried to do some research and get an understanding, but I am still at a loss.

Can please somebody explain what this means in VERY simple terms in relation to trumpet mouthpiece rims.

Thank you

cheiden · Posted: Wed Jan 17, 2018 2:12 pm Post subject:

http://www.grmouthpieces.com/alpha-angle.html
_________________
"I'm an engineer, which means I think I know a whole bunch of stuff I really don't."
Charles J Heiden/So Cal
Bach Strad 180ML43*/43 Bb/Yamaha 731 Flugel/Benge 1X C/Kanstul 920 Picc/Conn 80A Cornet
Bach 3C rim on 1.5C underpart

trumpet.trader · Veteran Member Joined: 02 Jul 2017 Posts: 200

TKSop · Posted: Wed Jan 17, 2018 2:36 pm Post subject:

Basically it's the shape of the cup below the bite... or the shape of the mouthpiece where the rim becomes the cup.

A more vague (and more commonly used term) is "undercut".
Does the cup drop steeply away after the rim (eg: Wick cornet mouthpiece)? That's a low alpha angle.
Does the cup angle in quickly towards the throat after the rim (eg: most Schilke _a4a models)? That's a high alpha angle.

In essence, the "alpha angle" is an attempt to put a quantifiable, measurable and repeatable quantity on the undercut...
... and why not? It's a factor some players seem to be very sensitive to.

In general this seems to be kinda the "GR way" (if I'm allowed to coin that phrase) - quantify absolutely everything and offer variations around whichever factors a player considers most critical (or whichever factors playtesting shows to be most important for that player)... and with everything quantified, comes the ability to keep certain factors steady whilst creating the balance by altering other factors.

B. Scriver · Posted: Wed Jan 17, 2018 3:48 pm Post subject:

Every mouthpiece has an alpha angle. Gary Radtke is the first person to actually define it in terms of degrees. The alpha angle is a critical parameter to all players. Of course you also have to consider rim contour, blow resistance, etc as well.

High alpha angle: Gives great support. Holds the chops in place. Works great if you do not engage a lot of lip in the cup. Articulations can be splatty and you can have a "frying eggs" sound if too high. This is also a major cause of bottoming out. Too high for a player and the mouthpiece will blow really tight. This is usually the reason that trumpeters drill out the bore. It usually has nothing to do with the drill size. Alpha is holding the chops too closed and not allowing free vibration.

Low alpha angle: Lots of lip room. Great if you engage a lot of lip in the cup but can be taxing and articulations can be woofy if too low for you.

The trick is to find the alpha angle that works best for you and intelligent play testing and knowing what to listen for is the way to go.

This is just a very basic description but I hope it helps.

Brian Scriver
www.grmouthpieces.com