New Rotary Speaker Modeling Pedal from Akai
January 19, 2003
Akai announced the ROTATOR, rotary speaker simulator that can reproduce the sound of the Leslie cabinet, with none of the problems normally associated with rotary speaker cabinets.
The complex sound of the Leslie is a mixture of many different physical effects. The upper horn and the lower rotor reproduce the upper and lower part of the frequency spectrum respectively, while rotating at different rates. The result of the rotating sound source is Doppler modulation and amplitude modulation of the signals. Furthermore, the rotating sound is reflected several times both within the box and in the room.
Additionally, when overdriven the tube amplifier of the Leslie provides a much smoother distortion than the usual transistor amplifiers, FET amplifiers or digital simulations. However, even with the tube amplifier the "smoothness" of the sound is limited. For example, a third harmony in medium or low pitch range sounds very bad since some overtones generated by the distortion are generally out of tune, and can be very annoying musically.
The Rotator uses advanced modeling technology to simulate the physical effects of a Leslie to a very high degree of accuracy. The Rotator goes even one step beyond the possibilities of the tube amplifier in order to make an extremely smooth distortion. A "multi-band distortion" is applied. The middle range of the input signal is separated into 15 very thin frequency bands. Each band is distorted separately before they are mixed together again. Since by this solution each individual band is practically monophonic, the distortion generates only the clean overtones of all sound components, eliminating the out of tune products.
For more information, visit their web site at www.akaipro.com. | 
