DIY Spekon Cable For Rel

My reasoning for using the wire (Duelund) I did was it matched the crossover and internal wire I'm using in my speakers. REL states their subs take on the characteristics of the amps their partnered with, logic dictates the wire to the sub has similar effect. I've tried various other brand of subs using low level connections and dsp, none integrated this coherently with the main speakers.

I've also gone to the extent of using same power cords on REL's and amps. PC's make a difference as well, perha[ps even more than the high level wire.

I heard great things about them, so decided to give signalcable.com’s REL cable a shot on both my S/510’s. I was pleasantly surprised with the increase in performance. Highly recommended.

You are totally overthinking this. The cable does not power the sub at all, it just carries signal to the sub. It does not need to be heavy gauge, or anything special. 

When REL states it takes on the sound of the amp, it is talking about the levels coming from the amp. If you have a heavy bass amp, the subs will be louder, vs a flat amp, that will give the sub a more mellow sound. It just mimics the signal from the amp to the speakers. 

Doubt you will be able to measure any difference with different cables. However, I did just swap the power cable on my sub, measured a 1-2db increase in sound over the stock cable. That shocked me. 

As said, just use the OEM wires for signal. 

Send your existing (too short) REL connectors here to be rewired?

https://www.takefiveaudio.com/categories/272-subwoofer-cables

+1 ted_b with low output impedance of amp, high signal levels, and high input impedance of sub no need for shielding or heavy guage.