Having a final output of 4ohms would be good if you were using a 2 channel amp because then you could run it at 4ohm bridged (effectively a "2 ohm" load, but I won't get into that). Since the amp you are getting is a 1 channel mono amp, you can't bridge it. Therefore it runs most efficiently when shown a 2ohm load. Theres some website that explains all this in detail. Anybody know the site?