There's no way for a refined metal to be absolutely pure- some kind of impurity always remains, at some minute level. However, 99.9999% vs 98% doesn't make an audible difference. Don't believe the comments from people who act as if they have the final say in magazines- almost all have some financial interest in their comments.
I don't think I have seen CCA speaker cable. Coax, sure, but not speaker cable. You can go to a big box store like Home Depot and get copper speaker wire that would work as well as anything, but you probably don't need 1000' of it.
Make sure whatever you buy is CL-2 or CL-3 rated, often referred to as CMR or CMP. CL-2/CMR is rated for in-wall/in-ceiling applications and CL-3/CMP is rated for use in plenum spaces. This rating is required by code and if an insurance company finds that you used non-rated wire in walls and ceiling runs and a fire resulted, they won't pay for damages. This is more important than brand, fancy colored wrap and the other crap wire sellers recommend.
The link has a chart- use that to determine the wire gauge for your system. If you go one size over or under, you'll never hear the difference.
In a tangle over speaker cable jargon? Here we help you understand it with some useful tips on buying your own.
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