rhumba,
I suspect Bose breaks up the cylindrical (pole) speaker into three sections (base and two 3 ft. pole speaker sections) for ease of transport. And based on what that fellow wrote, Bose seem to have incorporated stereo into their system, since he spoke of plugging in the L and R outputs of his keyboard. Whether the upper and lower pole sections constitute left and right speakers is not clear to me. Maybe each of the two pole sections has a left and right portion. I have not read anything that clarifies that point.
Paul C.