Hello everyone, this is my first post on here so excuse me if it is a little sloppy. I needed NAM advice on wiring up my amp for my subwoofer for my 07 r56. Currently my plan is to change the wires on the x9331 cable so the front and rear speakers flip to get rid of that 100hz bass cutoff. For my RCA converter should i tap into the rear speakers or should I tap into the x9331 cable? I know it would be a better alternative to tap into the x9331 but I don’t know which ones to tap into post operation. Any help would be greatly appreciated

 

If you really just intend to drive the front speakers with the radio's rear channel output and use the front channels for the subwoofer, you could just as well use the rear speaker leads and do without laying additional wires from the x9331 connector to the rear.

However, the front speakers will continue to be limited by the radio's weak internal amp. And unless both the amp and subwoofer are placed under the front seats (requiring their removal), you will have to remove most of the interior trim in order to either access the rear speakers and/or to route wires from the front to back (e.g. a power wire, should your amp need more than what the rear power outlet is rated for).

IMHO, a better alternative with minimal additional effort would be to:
- swap your RCA converter and amp for a high level input compatible, 2 ohm capable, 2+1 channel amp
- lay two regular speaker wire pairs from the amp's output back to the x9331 (connecting them to the x9331 front speaker input pins)

The benefits will be:
- better control of the front speakers frequency range (using the amp's high pass filter instead of the 100Hz cutoff notch)
- being able to replace the front speakers with aftermarket ones while ignoring their efficiency
- higher possible volumes overall