Bach's Symphonic trumpet mouthpieces use the standard Classic series cup designs but opens up the throat and backbore a little to aid the player in achieveing a bigger, stronger sound. Having these modifications done at the time of manufacture, using precise designs and under controlled conditions, negates the the need to have a standard mouthpiece reamed out by hand, which can create inconsistencies in playability and tone. All of the Symphonic series mouthpieces feature the larger number 24 backbore. Each cup size is available with 4 different options for throats ranging from the 22 to very large 26. Symphonic Series mouthpieces are completely made on CNC machines creating a precise mouthpiece every time. - the manufacturer/cdp
General Specifications:
• Large cup; powerful brilliant tone. • For players with a good embouchure. • 16.50 mm cup diameter • Medium cup • Medium wide, lowered toward the outside rim shape. • 24 backbore • 22 throat