Hal, would that be due 70.7 AND the probable 15 amp capability on the amp output?

No, nothing to do with what you are saying at all, in fact most amps today that are even larger only require CL2 wiring. Those Com-Tech amps are a few years old (8-10) and back then installers either didn't know or didn't care about speaker wiring unless you had an inspector who was sharp enough to know LV wiring and knew to look at the back panel of those amps where it says "Class 1 wiring required".

The class of wiring required is determined by UL or other testing lab specs which use a complicated formula of output current, current limiting, voltage and voltage limiting. The engineers that design commercial amps today are smart enough to design something that can deliver full power yet (and I'm guessing here) react quickly enough to a fault so that only Class 2 wiring needs to be used.

When I used those amps the wiring was in conduit and Greenfield whips to each speaker. I had a couple of thousand feet of 18ga TFFN in red and black twisted up which I pulled for the wiring.

If this ever should become an issue Jeff, it would, without a doubt be less expensive to just replace those amps though I would be crying because they are bullet proof.

-Hal

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