Low cost subwoofer upgrade

My 2 channel system is optimized for speed and midrange. The speakers are Voxativ Ampeggio single driver speakers. My tubes are vintage Western Electric (WE) 300B from ‘48 and ‘52 in restored WE monoblocks. The phono cartridge and SUT are Allnic. Great sound but thin bass. I added a pair of Rythmik 12 inch subs along the front wall. Improved sonic experience but I was still not there. I added a pair of REL T9x subs along the side walls. Better sonics: higher SPL. I thought the bass detail could be better. A colleague recommended that I ditch the courtesy cables provided with the subs. I substituted Cullen power cords and Cullen Neutrik interconnects. What an improvement in detail! A relatively inexpensive upgrade that brought the subs to full potential. I wonder if other Goners have experienced the same?