That's what it said on all my old LPs. Seemed very "state-of-the-art" at the time, but is now regarded with total contempt. As near as I can determine, it's a method of tricking your ears into thinking they're hearing a stereo recording when in fact they're hearing a mono recording.

How exactly is this done? From what I gather, it's simply a process of splitting the mono signal into two channels, inserting a delay so that they are slightly out of synch, turning up the treble on one and the bass on the other, and introducing varying amounts of echo.

Is that about it? If any audiophiles out there can explain this better than I can, I'd be very appreciative.