I'll just take your word on it too because I'm looking at it from an RCA stand point. RCA's send the audio signal to the amp, the amp provides the power based on it and the subs resistance etc. Changing RCA cables wouldn't increase the power output, might get you a clearer signal path but measured output should be the same either way. In this instance I'm looking at it this way, the rear speakers output might be cut by 50% but why would the subs output be cut since it is only using those speaker wires to get audio signal and not power?