What ohm to set amp


I have the Sonus Faber towers with matching center. Running a Marantz AV7005 with a Mcintosh Mc205 for power. I've read in a couple of reviews, where the towers were running at 4.1 to 4.7 ohms and the center was running at 6.2 ohms. They are 8 ohm speakers, can I run it at 4 ohms? My friend said I can run them at 4, but couldn't tell me if there would be issues down the road.
kalbi23
Al, thanks again for the education. So to restate what you said above, "[t]he tighter the regulation, meaning the smaller the +/- number, the LESS the voltage will increase as load impedance increases, and the LESS the voltage will decrease as load impedance decreases."

"An ideal voltage paradigm amplifier will have a regulation of +/- 0.0000 db. Its output voltage will not change at all as load impedance varies. And, per Ohm's Law, for a given output voltage the amount of current drawn by the load will vary inversely with the impedance of the load. So since power is proportional to voltage x current, and equals voltage x current in the case of a purely resistive load, the power delivery of a voltage paradigm amplifier will NOT "correspond to the magnitude of the input signal."

And as to Ralph's comment about tonal balance problems, I suppose using a tube amp that has a high output impedance implicates the mismatch issue more so than using a tube amp that has a lower output impedance.

Last and final point: I think I'll keep my day job.

And Al .... thanks again for the education.

Bruce
As to Ralph's comment about tonal balance problems, I suppose using a tube amp that has a high output impedance implicates the mismatch issue more so than using a tube amp that has a lower output impedance.
You've got it correctly!

Best regards,
-- Al