Mr. Bill,
Its my understanding that the 4 ohm switch limits the amount of power the reciever can put out.If the reciever is 100@ 8 ohm with the switch put to 4ohm you then are not pushing the same amount of power.It is a current limiting device (the 4ohm switch).

Rick


"A fear of weapons is a sign of retarded sexual and emotional maturity." Sigmund Freud