I have an old sony reciever (str-d1011s) on the back it has a switch that says 4ohms-8ohms, but underneath the speaker connects it says "use with 8-16 ohm speakers" My question is if i put the switch on 4 can I use 4 ohm speakers. My second question is it possible to use 6 ohm speakers without damaging anything. I would refer to the manual but it has long been lost. thanks