Pure Copper 99.9%+,
NOT Copper Clad Aluminum(CCA)
(IMPORTANT: Be aware when shopping/comparing speaker cabling. Copper clad aluminum means it's a aluminum wire with a thin coating of copper as a "skin". Audio uses the whole cross section of copper.)
Rating: CM and CL3 (Ok for CL2 uses as CL3 is a stricter code common in commercial applications)
16/4: AUDIO CABLE 4 COND 16AWG HI-STRAND OFC CM/CL3 75C 4003289 C(ETL)US 500FT
-High Strand Count of individual copper Flexibility because you want to have a complete wire length in tact in the end. If you use a wire with too few of wire strands (cheap cable), you risk breaking those in pinch points. You're not going to find this out until AFTER your drywall is up, painted and finished.
-Not too high of a strand count.
-More is not necessarily better in terms of strand count. If we could get away with fewer strands for quality, we would. -105 strands for 14 gauge
-65 strands for 16 gauge
-Jacket construction for "slickness" The jacket is round and has a coating on it to allow it to slide through installation holes quicker and stay more in tact.
-Box Design The box is designed for easy payout the whole way through. Spools will be "coiled" in such a way that pay out often kinks with that perfect coil twist. While that's good for garden hoses, it's a pain in the rear for installing wire.
-Near 100% pure copper wire strands Higher conductivity means lower heat over distance. Better bass at the limits of the wire lengths. Cost effectiveness over using the next larger wire gauge.
NEC Article 640: Audio Interconnects and Speaker Wires
Audio interconnect cables and speaker wires fall under Article 640, and so whether they can be installed in-wall or in other specific settings will depend on that article. Under NEC 640.21(C), these are in turn governed by Article 725, "Class 1, Class 2, and Class 3 Remote-Control, Signaling, and Power-Limited Circuits."
General installation of wiring, including installation inside of walls, is governed by 725.61(E), the principal features of which, for our purposes, are:
- (1) CL2 and CL3 are always permitted;
- (2) CL2X ("X" is a residential suffix, signifying a lower grade than plain CL2) or CL3X may be installed in raceways;
- (3) CL2X or CL3X, if under 1/4 inch in diameter, may be installed in a 1 or 2 family residential dwelling without a raceway; if nonconcealed, it may also be installed in multifamily dwellings.
So, if a cable isn't marked CL2 or CL3, is it suitable for in-wall installation? It may be. The NEC allows cable of a higher rating to be substituted for a lower rating, and therefore, any of the following may be used: CM, CMP, CMR, CMG, CL2R, CL3R, CL2P, CL3P, PLTC. CMX also may be used where CL2X or CL3X is required.
In a plenum, 725.61(A) governs; CL2P or CL3P are required, and CMP is a permitted substitution.
A riser presents a bit different situation, governed by 725.61(B). If you're in a single or two-family dwelling, CL2, CL3, CL2X and CL3X may be used (and, of course, any of the substitutions listed above). In a commercial building or multifamily dwelling, any of those cables are permitted if they are installed in metal raceways or located in a fireproof shaft having firestops at each floor. In a commercial or multifamily building, without a raceway or shaft, if the vertical run of the cable penetrates more than one floor, CL2R or CL3R must be used (or any of these substitutes: CMR, CMP, CL2P, or CL3P).