The spectrum plot was taken with no input signal, but the cable still properly terminated and the residual noise floor shown is around -160dBu, which I presume to be the AP noise floor. The electromagnetic interference from local mains wiring peaks to around -130dBu for the Vovox cable. Sorry you can't read the scale; the image zooming function seems to be broken!
I ran a variety of distortion and intermodulation tests, at a variety of levels, none of which revealed any significant difference between the Vovox and Chinese cable performance.
As I have said, I have heard differences in various Vovox demonstrations, but I'm not sure I'd say it was a definite improvement... Just different. Moreover, I've never been able to repeat the differences reliably on my own equipment.
I didn't mean to emphasise the origin of the comparative cable specifically. The point was that I was comparing the expensive special Vovox cable with a very cheap mass produced cable using ordinary unpretentious wire. It was something that I had lying around which happened to be the same length as the Vovox.
Vovox claim the sonic benefits of their design are due to a combination of the very non-standard construction, the shielding (or lack of it) and the insulation materials and conductive cores used.
I did once make a comparison cable using single core screened wires twisted together and observed the same poor interference rejection properties, so I think it's fair to say that most of that aspect is down to the specific construction.
Technical Editor, Sound On Sound