Bi-amping with Audioquest cables

Bi-amping or Bi-wiring within a single Audioquest cable will work fine. The reason it is not recommended has more to do with the sonic disadvantage of having deep bass information traveling in close proximity to more delicate high frequencies. The magnetic field created by the bass will modulate and distort the high frequencies to some extent.

This is the reason that true bi-wiring involves two physically separate pairs of cables. What you are doing is known as single bi-wiring (or single wire bi-amping). Dividing up the conductors internally within a single pair of cables is commonly done, just not ideal.

Lt346mp asks a good question. I have experimented quite a bit with those kinds of comparisons.

Comparing your example of a double bi-wire set of Midnight (bass) and Sterling (highs), to a single-biwire with a single Sterling cable, the Midnight/Sterling combo will win easily assuming you have a 3-way speaker. The reason is that the advantages of having two physically separate cables along with double the overall gauge trumps any advantage offered by the superior metal quality of the few Sterling conductors that would be devoted to the low frequencies in a single bi-wire.

Also, with most most loudspeakers (nearly any 3-way), the cable connected to the bass will not be as critical in terms of metal quality. The kinds of improvements one would hear with better copper or silver at higher frequencies is not as significant at lower frequencies. Is there a sonic difference with better conductors at low frequencies? Yes, just not to the same degree as with high frequencies.

With 2-way speakers, where the crossover occurs right in the critical midrange region, it is much more important to have equal metal quality (and typically identical cables, or nearly identical cables) for the highs and lows. This is true to a much smaller extent for some 3-way speakers with a higher x-over point or a gradual 1st order (6db/octave) crossover, like a Vandersteen or Thiel.