I’ve been thinking about this thread the last few days (must be bored); and I’m a little confused on one matter.
Most high sensitivity measurements in the lab with various scopes and analyzers are performed using the industry standard RG-58/U cable with BNC coax connectors. That cable is basically the lab standard for low noise / artifacts. Here is a link to the specs:
https://catalog.belden.com/techdata/EN/9201_techdata.pdf
The RG-58 has a capacitance of 26 pF/ft to 29 pF/ft; placing it solidly in the middle of the capacitance values tabulated by @bongomania for the MI cables.
Based on the analysis in this thread, one might expect impedance artifacts with RG-58 in the neighborhood of 1.5 kHz to 2 kHz. But, I am quite certain based on a LOT of years using RG-58 for extremely high sensitivity low frequency (< 1.0 MHz) measurements that such artifacts are reliably not observed with this cable.
This leads me to believe that the peaks noted in the Spectrum Analyzer measurements linked in this thread are related to a circuit specific resonance that happens to exist in the particular test rig, which does happen to vary with cable capacitance.
I would be VERY cautious not to over interpret the Spectrum Analyzer data.
Also, there are other transmission effects not included in ideal transmission line models. Dielectric loss, in particular, can be an issue for certain polymeric materials, especially rubbers.
Interesting topic and props to @bongomania for taking a swing at it. But, I don’t see any data yet, either in this thread or elsewhere that would suggest any particular cable at any price point produces superior audio response. I do agree with the comments about durability and quality of connectors being important.
Carry on.