So, I just got home from a few weeks on the road and ask the wife if she minded me continuing to break in the LSis. She says "cool, let listen to some old school Beastie Boys" and proceeds to turn the sucker up 'till I can literally see the lights in the room dimming slightly with the bass line.
That was -1.5db, two channel and the sub.
She was too busy dancing to notice the grin on my face... I had high expectations when I got them and was pretty unimpressed with the 15s when I got them home. I hadn't owned a set of speakers that needed to be broken in, so I was dubious. But, as they break in they are getting sweeter every day. The sound stage is actually widening and getting tighter at the same time. Go Polk!