If the SD-7 demonstrator is being completely honest in the multitrack demo, Ketron has been able to accomplish something never seen before. If you listen, the demonstrator states that the song he is mixing is a surround sound .wav file. As he pushes the faders up and down...there is complete separation of bass, drums, Stings vocal and guitars. There is no leakage or bleed from other tracks. Not even in the reverb and delay on the vocal track. The guys at my local music store (Brent's Music) could not believe it as they watched the video. They said they must have gotten the multitrack stems to pull this off. Everyone on this site knows how weak voice cancellation technology is. If this feature is real...Ketron may have discovered a technology way beyond anything available today utilizing software or current hardware options.