As you've posted many questions in your time(over a year) on our forum that I think reading a few articles on the AH main site might clear up. I do suggest your read them.
As you've been around the block with questions. Let me summarize some facts for you.
1. Bi-wiring is useless if you have the properly gauged wire.
2. Changing receivers will not change your actual sound in direct mode, but my change the perceived sound.
3. To have a real upgrade in power you will need an amp with at least twice the power of your receiver.
Questions.
Did you ever blow that sub?

If so what did you replace it with.
Why would you biwire a sub?