Synergistic Red Fuse ...

Al, thanks for your response to my question on "pushed-value" SR Blacks in my AC input.  Of note, the front-panel display on each amp now reads at 120-121V, whereas at lower fuse ratings, the line voltage was at around 117V.  The operating range of the ARC 210's is 105V-130V.  
I'm glad you asked about the REL subs and Neutrik SpeakOn wiring.  The Neutrik plug is the NL-F4C, a four-terminal plug supplied with the REL's.  When I went to mono block amps and a sub for each amp, I followed the advice of my High-End retailer here in Mpls. For Magnepan speakers, I am using the 4 ohm speaker output terminals on the ARC 210s. I have connected both SpeakOn red and yellow (+) wires onto the 4-ohm (+) terminal of the amp and the black (-) wire to the 4-ohm (-) terminal on the amp. I left these wires in their original places on the Neutrik plug end. And where do I have the Neutriks on the REL input terminals?  I have left them in the unbalanced high-level inputs a long time ago.  This is the input recommended for a stereo amplifier.  The balanced high-level input is described in the REL manual as being used for  bridged-mode amplifiers. Thinking this was not my situation, I have ignored that input all these years. although the REL manual goes on to say, "Monoblock amplifiers may or may not be bridged output." Perhaps I should be using the balanced inputs on the REL's?
Regards, Joe 

 While this is as patently exciting as watching paint dry, may I get back to Al on my REL subwoofer hookup?  
Al, thanks for your research into REL's instruction manuals for the proper wiring of a mono block amp to the sub's balanced input.  I have not experienced any adverse effects from my equipment by combining the yellow and red wires onto the (+) speaker output terminal and the black onto the (-) terminal, and I hope this is because I have been using the unbalanced input on the REL all along.  On the Bryston 4BSST stereo amp I used to use with only one REL Stata, the yellow and red were each attached to the left and right (+) speaker output terminals respectively, and the black was attached to one of the (-) output terminals, user's choice on that one.  With going to a mono amp for each channel, I was told to combine the red and yellow as first described, but as you have informed me, this does not account for the full amplitude signal from the (-) output.  I am hoping the unbalanced input on the REL does account for it, as the system does sound very pleasing as is, but I am interested in revising the hookup to the balanced input, as well, per your invaluable advice. 
Regards, Joe