Everything I'm reading about the Six is that it is rated for 4 him speakers. I had my Seven gone thru by a pro who replaced several caps, and made sure it was running correctly.
As long as your receiver doesn't have any issues, I see no problem using 4 ohms in normal listening. I use mine maybe an hour a day, if that. No problems. Nice sound.
tjanks glen..
Im leaving my radio turned on overnight.. hopefully it will not wear too fast.