Neat. Sorry, I hadn't realized you were able to drive the amps hard enough for them to shut down, or I would have been a bit more enthusiastic about your bi-amping experiment
I guess someone not fighting a flu bug could probably use that 1.5 dB number and work out the actual power split between woofers and mid/tweeters, but that isn't going to be me, at least not for a few more days.
EDIT - I assume we're getting into REALLY FREAKIN' LOUD territory here. You might want to build a small insulated structure on the outside of your listening room similar to what Axiom uses for high volume testing.