Rud, your 3808 doesn't say that it wants to push 8 ohm speakers(despite any claim to the contrary in the manual), in fact it has no idea what the impedance of a connected speaker is. It has to supply a certain voltage to drive a certain current to produce a given amount of power, following Ohm's Law. If it can supply that voltage and current it doesn't matter what the impedance is. Any receiver can drive any speaker, including one rated at 4 ohms, to some extent. The question is how loud and how long. The M80s are slightly above average in sensitivity and don't have any unusual power requirement. Your 3808 has a very powerful amplifier output, including into 4 ohms, and is one of the many receivers that should have no difficulty in driving the M80s adequately in the vast majority of setups.
