In approaching this project, my philosophy was to lighten and simplify the original Leslie design as much as possible, fine-tuning it to the guitar while maintaining a tight budget and not compromising on tone or function in any way. So, ever a believer in the DIY spirit, I decided to build one. What would happen if a rotating speaker device was designed from the ground up for our 6-string weapon of choice? Could it maintain and embellish the frequencies of our instrument while giving that beautiful, room-filling, three-dimensional effect? Other than the vintage Fender Vibratone and scant offerings from Hammond-Suzuki and Motion Sound-some guitarists might also recall the elusive Mesa Boogie Revolver-nothing really scratched my itch.
I always wondered if the Doppler effect could be applied specifically to the guitar. The Leslie speaker operates on this principal on a relatively small scale, making the effect more subtle then a moving ambulance siren, but all the more beautiful. As a sound source gets closer to you, it will increase in pitch and volume, and the opposite will happen as it moves further away. This is a physical phenomenon that describes the change in frequency as an object changes position relative to a sound source. Leslie speakers operate on a principal called the Doppler effect.
