Almost all basson accordions go down to the low C. When standard A is 440Hz, you can go down to 220Hz by using the L reed, then one octave lower is 110Hz, another is 55Hz and in that octave you go down to C, so it is really low.
There are some basson accordions that have a key for the B below that C, but not all of them (maybe none of them?) have a B that actually plays. (Zero Sette has this key and Giulietti, but that's no surprised as Giulietti accordions were made by Zero Sette for many years. I don't know whether the B plays as all music written for basson accordion assumes you cannot go below C.)
Almost all basson accordions have a fixed LM combination, no register switches to use just L or M.
There is one exception: The Pigini Basson P39 or C39 is 3-reed: LMH and it has 4 registers: L, LM, LMH and LH. (The P39 has 39 notes, from C to high D, which is a configuration shared with some others like the Bugari basson. The C39, despite what the name says, has 40 notes, from C to high Es.) The old popular Hohner basson had 34 notes, going up to just A.
I have played a Bugari basson for many years and since a few years I now have the Pigini C39. The basson is actually my favorite instrument in an ensemble or orchestra.
Some basson accordions (Bugari for instance) have a 180 degree "winkelbass" for the L reed, which gives a bit more punch to the L reed. The Pigini does not.
Last edited by debra
on Thu Mar 16, 2017 8:53 am, edited 1 time in total.
Paul De Bra (not Debra...)