Dude -run from the LFE out on the surround processor directly to your subwoofer in. If you have L&R inputs check the manual to see if they recommend using one or the other or if you will need to add a Y.
While you have the manual open, check to see if your sub has auto-sensing - meaning that it will turn on automatically when it detects signal and go back to standby some number of minutes (varies by mfgr) when signal stops.
Do not add an amp into the loop as there is no way (and no reason) to bypass the amp in most powered subs. Nor are most amps up to the task of handling a sub.
Good luck
While you have the manual open, check to see if your sub has auto-sensing - meaning that it will turn on automatically when it detects signal and go back to standby some number of minutes (varies by mfgr) when signal stops.
Do not add an amp into the loop as there is no way (and no reason) to bypass the amp in most powered subs. Nor are most amps up to the task of handling a sub.
Good luck