Biwiring an Amp into a Single-wired Speaker?

That amounts to putting the two pairs of conductors in the cable in parallel, which could very possibly be sonically beneficial. Although there is also at least a small chance that the results may not be subjectively preferable.

Paralleling the two pairs of conductors cuts the resistance and inductance of the cable in half, compared to a single pair of similar conductors. Which, if it makes any difference at all, figures to be beneficial. It will also double the capacitance of the cable, compared to a single pair of similar conductors, which probably won’t make much if any difference assuming that the cable is not unusually long and (as I suspect in this particular case) that its capacitance per unit length is not unusually high.  (If the total capacitance of the cable is unusually high it may have adverse effects on the amplifier's sonics).

There may also be differences resulting from other effects, such as RFI/EMI that may be picked up by the cable. Especially if your amplifier uses feedback, which would increase its sensitivity to any such pickup. But the degree and character (good or bad) of differences in that kind of effect, if any, between a single pair of conductors and paralleled pairs of conductors would have little if any predictability.

Regards,
-- Al

What Al said :-)

Wow, Al, thanks for this informative and well-written response.

One follow up question: I have 4 fancy WBT connectors at the speaker end of my biwire cable. Would you recommend moving them to the amp end, or use 4 lesser connectors at the amp end, and then us two of WBTs for the combined speaker connections?

Thanks, Ubersujith!

Regarding your follow-up question, I doubt that the answer has much predictability.  And I wouldn't be surprised, for that matter, if it doesn't make much difference.  But FWIW I suppose that at least initially I'd do whatever is simplest to implement.  Which if I understand correctly may be connecting the four WBT connectors to the amp, and connecting the two + connectors at the other end to the + connector of the speaker, and the two - connectors at the other end to the - connector of the speaker.

Good luck.  Regards,
-- Al
 

Hey Al, I just set you up for another edifying reply over in the amps pre-amps forum. Cheers.