I have a question on the Sony DA5ES and the impedance switch on the rear. The impedance switch is a 4ohm - 8ohm selectable switch, where if you have any speakers lower than 8ohm you are to set the switch to 4ohm. I have all 6 main speakers (fronts, center, surround and back surround) rated at 6ohms. I set the switch in both modes for a week at a time (one week at 4ohms and another week at 8ohms), and didn't really notice a difference - so I left it on 8 ohms. BUT, the manual indicates that at 8ohms the receiver is rated to deliver 110 watts per channel, but at 4ohms it is only rated to deliver only 90 watts per channel. So my question is, am I doing any harm to the receiver or speakers by leaving the selector set to 8ohms? I do notice that the receiver set to 4 ohms runs very cool - and gives off almost no heat even after extended listening periods. With the switch set to 8 ohms the receiver gets fairly warm (but not hot). I think I understand what the switch is utilized for, and it is most likely there to protect the receiver from overloading trying to drive too low an impedance. But I don't really want to limit the overall power output to 90watts by setting the switch to 4ohms. What are anyone's thoughts here on this subject? Obviously if I don't really hear any sound quality difference it might be safer to set the switch to 4ohms and forget about it? Anyone?