9 gauge vs 12 gauge Jumper of same brand cable

The result will vary from amp/speaker matching.
We did an experiment and got different result.

Using same pair of bi-wire speaker:
Setup A - Stock brass plate jumper
Setup B - Bi-wire cable
Setup C - 3rd party jumper cable
Setup D - Two runs of identical single run cable
We have tested with 4 different amps and got mixed results
All concluded that setup A is the worst sounding with all 4 amps.
Setup B, C, and D are very similar
In some amps, setup D works the best. More clear, transparent. Improvement in low frequency.
Almost no difference between B and C

This is subjective test with our setups and systems.
Although it is not the most scientific way, it gives listener a general idea about bi-wiring.

Thanks again ,S23chang. for such illustrative and helpful informations.
On setup D - is it 2-pair of identical cable with stacking up the spades on both end with the jumper remained in place ? or having the 4 spades connected to Upper and Lower spkr binding post / while only 2 spades connected to Amp end (jumper removed)
I really need your confirmation ,please
Thanks
Simon

In setup D, the jumper brass plate was not in the picture.
Yes, two pairs of identical cable running parallel.
On the amp side, there is only one set of output, we use banana plugs for the convenience to stack them.
On the speaker side, we run bare wire to each upper and lower binding post.

Hi,S23chang .
just for my better understanding- Is the Setup D the exact same as "Discrete Biwiring"?
Thanks
Simon

YES. Discrete Biwiring is the setup D