Interesting little curiosity. I wonder if anybody can comment on this... Equipment: Yamaha RX-V1000, Paradigm Studio 100's, and Energy 8" sub. This question is specific to two channel listening only. That is, in "Effect off" mode. I've tried various settings for Mains (Large/Small), and LFE/Bass Out" to see what I like the best. I've noticed something which I can't readily explain. I would expect these two settings to sound the same: Mains - Large Bass Out - Both (1) and Mains - Small Bass Out - Both (2) But in fact, they sound slightly different. Specifically, (1) sounds stronger in the lower midrange (or upper bass) than (2). Why would this be?? I'm hypothesing that in (2) the receiver is sending half the power of the bass frequencies to the mains, and half to the sub, but the sub is failing to fully reproduce the higher frequencies it sees, leaving a "half power hole". But in the case of (1), it sends the full bass power to the mains, and then augments it with more to the sub, so I don't perceive the hole - just better low end bass. Thoughts? Martin.