| I'd like to know the answer too! Bore on a trumpet is usually measured at the second valve. How can it be a dual bore? Conical I understand or even step bore. Dual bore? You would have to measure it in two places!
A trombone is measured at the slide. The mouthpiece side can be one size, and the slide part going to the bell be another. Kanstul makes a trombone that is a .530 bore/.547 bore trombone. But that makes sense. (BTW, the slide only fits one way).
How can you have a dual bore trumpet? I too, shall await the answer.
Jim |