I did run the same length of the same wire (Audioquest) for both sets. The difference might be partially or even wholly due to the increase in effective awg. Having just invested in a new turntable and cartridge, I’ll just enjoy the current improvement and any further cable experimentation will have to wait for another time. ;)
My experience with bi-wiring
Not wanting to debate the issue, which has been done ad nauseum, I just wanted to share my experience in case it's of help to anyone else in a similar position. Originally I single wired my speakers with jumpers made from my speaker cable, but I had been curious about bi-wiring and read all I could both pro and con. The main thing I gathered was that it is a contentious subject that there is no consensus on. I was reluctant to spend the money on something that may not pan out, but as the maker of my speaker recommended bi-wiring, I finally decided to give it a try. I was impressed that there was a worthy improvement in detail/clarity across the frequency spectrum. Admittedly any change is speaker dependent and YMMV, but if your speaker brand advocates it, I suggest it's worth a try.