The Klipsch speakers are extremely efficient - your 102dB efficiency rating is drastically better than the 90dB or so for my Paradigms (which were driven once upon a time by Outlaw's Model 1050 receiver). The Model 1070 should have no trouble at all driving your speakers to whatever level you can stand. (As a bit of comparison, long-time forum member and movie soundtrack engineer soundhound uses some large Altec Lansing horn speakers that are more efficient than your Klipsches - if I recall his setup correctly, 'hound drives his horns in an active tri-amped configuration using tube amps rated at 5W each.)