Because its overkill. And yes it was left over from an MRI install. And Yes it was a pain to work with (especially when its cold), luckily my room has crawl space surrounding it so it was just a matter of laying it all out. It's really not that big. It's the shielding that makes it so large and it's O2 free
(not that it matters much

) With wire that big I barely have any resistance, and the runs from my AV closet to my mains is pretty long. It works well but I'm still using integrated amplification from my receiver (140x7) (which probably equates to about 80-90). I'm still undecided on which amp will fit my need, but one thing for certain is with 8AWG I can just about feed any amount of power I want.