Why are they doing this?

Kinda vague, huh? I'll elaborate. I have Emotiva XPA-1 monoblocks driving Magnapan 20.7's. Before that they were powering Mag 3.7's. They are 1000 watts into 4ohms. They never clipped. I did play them loud but not ridiculously loud. These amps have blue led meter lights that move in sync with the amp output and they would peak a little passed halfway. Occasionally a bit higher. Recently I added a pair of REL G2 subwoofers. They are connected one left and one right as per the manual. That would be to the speaker posts on the amps with the supplied neutrik cable. Upon connecting the subs, the blue led's no longer move. (Yes, I've checked the switch that turns these on and off) Also, three times now, the amps have clipped, once left channel and twice right channel. It was at a pretty good volume but not where it was outrageous. I talked to a tech at Emotiva and first off, he had no knowledge of REL subs and how they are connected. After I explained it he was kinda at a loss for words having obviously never heard of connecting subs to the speaker posts on the amps. His explanation for what was happening was that the subs are 4ohm and the 20.7's are 4ohm so that's driving the load down to 2ohms and that's causing the clipping and the amps cannot detect 2ohms so that's why the led's are not functioning. If this is true then Rel subs cannot be used with any 4ohm speaker or the same problem will occur. I'll be honest, when you start talking ohms splitting and other electronic stuff I tend to get lost. Anybody care to take a stab at this?