An innovative capability of the RSP-550 is the rotary algorithm. This effect basically nails the elusive rotating speaker sound made famous in pop and jazz music in conjunction with an organ, although guitarists have discovered rotating speakers as well. An authentic rotating speaker system consists of high and low frequency horns which physically rotate. When the engineers at Roland tried to duplicate this effect, they had their work cut out for them.

The problem is that both speakers rotate at different speeds. Thus, the lows are constantly speeding up and slowing down completely independent of the high frequencies. Roland recreated this effect by taking the audio input and splitting up the signal into two bands, high frequencies and low frequencies.

The RSP-550 then allows you to choose a slow or fast speed for the low end, and a slow or fast speed for the highs. Another great effect created by rotating speakers occurs when they are "kicked" on. Once they start rotating, they gradually build speed and create a Doppler effect. This occurs on both the low and high speakers. The RSP-550 lets you choose a low rise time, and an independent high rise time. just like the real thing. The "mic placement" on the speakers is also variable with the RSP-550 high level and low level controls.