Bob, welcome. Yes, that's probably what the Denon rep did tell you. It appears that both amplifier and speaker manufacturers operate with what appears to be an excess of caution in this area, possibly hoping to avoid getting trashed on the internet if a problem does develop. Any amplifier, including those in receivers, can drive a speaker rated at 4 ohms without shutting down, depending on how loud and how long it's driven. Some 4 ohm rated speakers(e.g. the M80s)are actually easier than some 8 ohm speakers both from the standpoint of watts and current, since they're more sensitive. It shouldn't be assumed that there would be a problem in your use pattern; trying first results in no problem in most cases.
