After starting this thread last February, I purchased the Synergistic Alpha Sterling x2 from The Cable Company. This is Synergistic's least expensive REL cable. It was a trade in so I received a discount. I think I paid $250. I decided on that cable after discussing the Synergistic cables vs. the XLO with someone at The Cable Company. They sell both lines. You may want to contact them to learn their current view.
The Synergistic is a definite upgrade over the stock cable, producing deeper, tighter bass. I also upgraded the power cord to an Audience, around the same time, which produced more authority. After these changes, I had to reconfigure the controls, and reposition the sub to get it to sound right again. It is a worthwhile improvement, but I did not expect killer bass since I am running it off the speaker outputs of a 300B tube amp, fed by a tube preamp. The sub does mate seamlessly with the main speakers.
Another unexpected, and very welcomed brnefit, was that when I plugged in the x2 power coupler into the electrical socket, it eliminated a significant hum that was in the system previously!
The Synergistic is a definite upgrade over the stock cable, producing deeper, tighter bass. I also upgraded the power cord to an Audience, around the same time, which produced more authority. After these changes, I had to reconfigure the controls, and reposition the sub to get it to sound right again. It is a worthwhile improvement, but I did not expect killer bass since I am running it off the speaker outputs of a 300B tube amp, fed by a tube preamp. The sub does mate seamlessly with the main speakers.
Another unexpected, and very welcomed brnefit, was that when I plugged in the x2 power coupler into the electrical socket, it eliminated a significant hum that was in the system previously!