Well this is a 1980's amp. Probably never made to do 4 ohm loads.
It works great for 6 ohms as what the Polks are. But 4 ...it dose NOT like. There is nothing wrong with the setup...I've run this for 20 years. I double checked everything. Its basically the amp dose not like the 4 ohm load..period. This amp never shut down running 2 speakers, the Polks at 6 ohms and a set of old large Advents at 8 ohms....pushed to the max.

The amp, no matter how good it sounds..just dose not like the 4 Ohm load.

Yeah it will work if i don't push it too hard....but the point of the speakers was to push them. Basically anything over 50 watts the amp shuts down. Not about to blow up the amp...so it needs a new amp. At least for these speakers.