I have KLF 20s as main speakers in my system and I'm addind a sub woofer which I built using a Shiva driver and a Parts Express 250W plate amp. I plan to use the speaker level inputs.Instead of wiring from the receiver to the sub input and then from the sub output to the mains, can I wire from the receiver to the mains and then from the mains to the sub inputs? Will this change the main's ohm rating?