I think if you have more than one output from your pre, and you already have the quads anyway, you might as well try it, just to see. Completely different system, I know, but I did this with my Sugden amplification and SD Acoustics speakers, and I'm very happy with the result. More control, authority in the sound. No tonal difference in the sound, but I wouldn't expect that, but the amps 'grip' the speakers in a way that wasn't happening with just the one amp running them. It's not an enormous step up, and certainly if I'd bought the second amp at new price, definitely wouldn't have been a grand and a half's worth of upgrade, but for the £400 I paid secondhand, I'm very happy. I recently did a test and swapped back to the single amp, playing the same track both ways, without altering the output level from the first amp, and I was still absolutely happy with the bi-amped setup. I have no idea of how the quads deliver current though, as it seems they have other considerations there, but if it's a simple matter and you have all the relevant parts, what's to lose in trying? Looks like the 22s have three sets of binding posts, so that's easy. You can actually get a splitter that will give you more than one line from a single output, if the pre has only one output, but I know not whether such a way of doing things is sensible, electrically speaking. If you were going to get into active crossovers and such, then you'd want to be bypassing the internal crossovers in the 22s, which is a whole other ballgame, as others have said.