Thanks for the updates. It looks like a reasonably competent speaker application cable. PTFE is comparatively stiff to begin with, and with the thicker dielectric layer typical of the Mil- types, I am not the least surprised you find it far from limp.
Using the odd number of cables in the bundle there can't be any noise cancelling effect due to common mode rejection, but there should be little need in a loudspeaker application. Keep your speaker cables away from AC lines, cross at right angles, and so on. The usual good practices. The capacitance values would be complex but that is also not generally a critical criteria with speaker cables, although in some cases can contribute to instability. As long as it's reasonably low it should be a non-issue.
That leaves resistance ... we can let that fall where it may, as the overall equivalent AWG is large and it looks like you are benefitting from a relatively short cable length overall ... and finally that brings us to inductance, which is important for amplifier > network / driver > amplifier circuits.
It appears that you have a low rate twist to combine the two legs into the one Techflex® -encased +/- cable assembly. That is different from a pure parallel lay as far as inductance values would go. Still, one would expect the values to be low, all things considered, in your geometry.
All the above might result in a measurable rolloff above perhaps 10 KHz, but even if it could be graphed the values would be extremely low ... much less than a tenth of a dB at 20 KHz. Probably even much less than a tenth of a dB at 100 KHz. Group delay will be extremely low (low resistance, good conductivity of copper) ... measurable, again, but only just. Perhaps the high frequencies will arrive at the ear first by an insignificant amount of time (nanoseconds, and only a few nanoseconds at that).
If you have access to some test equipment it would be interesting to see your results, but to be honest I'm not sure we could learn much from them, especially since we can't be there to hear the result.
So, that leaves subjective evaluation, then. Enjoy (or not, as the case may be).
Is that a PVC jacket or some other material holding the 5-cable bundle(s) together? It looks like something else. It's not terribly important in light of the thick PTFE dielectric on the cables themselves, just curious.