SatK, I really think you should be looking for another avr to use a pre when you get the EP800 or theA1400, I think you will still be having issues. All that popping/clipping(?) in the LFE can't be good for the subs amp either.

Jason
M80 v2
VP160 v3
QS8 v2
PB13 Ultra
Denon 3808
Samsung 85" Q70