>>John, my guess and I'm sure I'll get slammed for it...

Well, bumped maybe, but not slammed. Bumped lots of times... by at least two people named John...

>>... is that before I had one monoblock driving all the drivers (6), and now have 2 seperate monoblocks. So one 300 monoblock is probably able to drive the woofers more efficiently/easily by itself, then when it also has to drive the mids/highs also.

This was discussed a lot recently, not sure if in this thread or another one. Consensus was that the crossover shows a much higher impedence outside the frequency range, so the combined impedence in the woofer range is only a tiny bit lower than the woofer alone. A tiny bit might be enough, I guess...

OK, here's an interesting question for JohnK or others. I think we all agree that you don't get any more *voltage* headroom from biamping without a crossover before the amps (so the amp normally clips at the same input level as before), but I guess you would get a bit less total *current* draw on the woofer side if the impedence outside the woofer frequency range was higher ?

We should look at the M80 impedence curves again to see if the impedence dips in the crossover region between woofer and midrange -- if so, separating the two might eliminate the dip and a potential trouble spot for the amplifier...

>>That being said, I'm guessing it had a little more headroom.

Current, not voltage headroom. Normally that doesn't make any real difference since amps clip when they run out of voltage, but this *is* a hint that the problem might be slightly over-touchy current-sensing circuitry in the amplifier.

It would be fair to say "duh, of course it's in the current sense logic if you only get problems with 4 ohm speakers" at this point but it wasn't so clear to me.

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