ohms

[Edh63]

Hello -

I've got a question. I'm a little confused on what ohm setting I should set my receiver to on my 705. It gives me two options, 4 ohms and 6 ohms. I've used both for both TV and BD playback, but I really don't know that I can tell if one setting is better than the other... in what I hear.

Am I correct in understanding that it creates more stress on the receiver to run it at the lower setting... 4 ohms in this case? My speakers are rated for either setting but I don't know if I should use one over the other for any performance contrast. Does one setting over the other make a difference in the finished product... sound?