Bi-wire v's single with jumper leads.

Bi-wire by a mile here.....your results may vary. Maybe my supplied jumpers were inferior,I don't know. My "theory" is the LF and HF present two different loads in terms of impedance and frequency and having two sets of cables to carry these separately is better. Also besides my system I have never heard a system that didn't improve from bi-wire and I set up many when I was a dealer both on the display floor and in customer systems. For these comparisons
the same type of cable was always used for LF and HF within a setup although the experience overall represented several types/brands of cables and speakers.

ET

In my comparisons of the same exact cable in a Bi-wire vs shotgun with jumpers, the Bi-wire wins out for a more pleasing musical experience. I find the soundstage to be larger, bass is better defined with a better sense of pace. Treble is sweeter and cleaner. Of course, the cable has to be one of quality and more importantly, it must be synergistic with your amp/speakers as well.

I've once tested my biwire Analysis Plus cables in a configuration where I've connected both HF and LF spades together to a single binding post on the speaker side, and use jumper wires from HF to LF. I couldn't tell any difference between that and the proper biwire setup. I did hear differences when I went from Analysis Plus to Cardas to Kimber. But not when I used the biwire cables in such configuration.

I noticed better coherence as well in the single run when comparing AP Oval 9 single versus biwire.

When using Audience AU24 or Ridge Street Audio Poiema, I always used the high quality factory matching biwire jumpers.

If you have speakers that are designed for it then you can reduce distortion. (TYhis requires a speaker with crossover sections that can be separated)

See this article

If you don't hear a subtle difference then perhaps...

1) Your speakers are not designed for proper bi-wire
2) Your amp is not doing enough to control the output (output impedance may be too high)
3) The speaker crossover is of high order and it dominates or something else is masking the IMD distortion reduction
4) Your bass woofer is super linear and creates only inaudible harmonic/IMD distortion/breakup outside of its intended band (unlikely).