Would it? You’re allowed to use chapter 3 wiring methods for audio, but two speaker circuits is four “ungrounded conductors.”
Red and black are fine for this purpose. I’m not so sure about white and bare.
Red and black are fine for this purpose. I’m not so sure about white and bare.
The reason for the 4 AWG rule is probably an economic one. Having spools of larger conductor cables in a variety of colors is not inexpensive. Allowing the reidentification seems reasonable, though I'd probably argue the cutoff could be thinner than 4. The multi-conductor cable exception is a practical [and economic] one. You might not be able to get multi-conductor cable assemblies with the exact color coding you need.