thats not a good choice for mic cables. That is a single conductor. You would have to twist a pair and add a shield. It's not bad wire, just not the right configuration for mic cables.
You want 2 or 4 twisted conductors already covered by a woven shield.
Something like this:
http://taperssection.com/index.php?topic=74316.0 or you can find some on ebay also.