In my experience the PB1000 doesn't stack up against Axiom towers.
I have the M80s in my system started with a PB1000 due to the low end of my M80s basically totally masking the PB1000 out right. I'm a proud owner of an E.P.500.
Mind you all the reviews I've seen on the 3000/4000 series have been very good. Plus they're rather large subs as well, Might help them actually produce something below 25/30 Hz.
If using Axiom towers I highly recommend one of the Axiom subs as well.
Before I went to towers SVS was sufficient {M3/M22} set ups I thought it worked great. Just not enough power for towers.
