I am using a pair of Bose speakers that fit on the Yamaha mounts that fit on the tyros 2 and the original Yamaha Bass woofer for this keyboard. They are ok for in the studio. I have a sound wall composed of many amps and speakers I can plug into but these bose work pretty good.
Bose 161 left and right.
I bought them used from Donnie Pease so ask him if you want more info.
I am happy with them,
Bebop