When I first bought my Rel Stadium 2 almost 15 yrs ago I swapped the stock cable for the Signal Cable and noticed a faster, cleaner, deeper extension and was pleased with the improvement to cost ratio. I have also played with power cords ranging from the Signal Cable to VH Audio Flavor 4 to several others. Overall, no matter which speakers I combine the Rel to it is always a significant improvement in image presence and soundstaging...this is regardless of how deep the main speakers extend. I will almost go so far as to say the presence of the Rel adds benefits to practically any speaker system it can be properly integrated to. It's that profound. For the record, my speakers, all of which have found the improvement were/are:
Martin Logan Aerius I's, Audio Physic Tempo 3's, Silverline SR-11's and 17's (mini monitors naturally appreciate the Rel), Silverline Sonata 2's (essentially full range...almost) Apogee Mini Grands (already with built-in subs) and currently my fully rebuilt (by True Sound Works) Apogee Duetta Signatures...
Every instance was noticeably improved...Rel subs are a wonder...well worth it, IMHO. Good luck
Martin Logan Aerius I's, Audio Physic Tempo 3's, Silverline SR-11's and 17's (mini monitors naturally appreciate the Rel), Silverline Sonata 2's (essentially full range...almost) Apogee Mini Grands (already with built-in subs) and currently my fully rebuilt (by True Sound Works) Apogee Duetta Signatures...
Every instance was noticeably improved...Rel subs are a wonder...well worth it, IMHO. Good luck