subwoofer cable question

hi all, i am running the 7.1 analog outputs from my bluray player into my multi-channel inputs on my processor.

i am using 8 identical rca interconnects for this hook up.

my question is... should i be using a subwoofer cable from the analog output (bluray) to my processor's multi-channel input to acheive better sound quality from the subwoofer?

thanks everyone,
cheers.