It was not a stereo cabinet as made by Sunn. If the input makes any difference, it's been rewired. I don't think that's a very good idea. All of the drivers are in the same interior volume, so running it stereo means that half of the drivers will be acting as passive radiators for the other half. Even worse, if you run an amp into both inputs, then the drivers powered by one amp will cause the other drivers to induce a voltage, feeding it into the output of the other amp. Might let the magic smoke out...