Hey bud, if your system is not Logic 7 in South Africa, it automatically means you dont have an amp and have the standard 6 speaker setup.
You can tap the signal without loosing the feed to the speakers. I initially had the LOC to the rear speakers and it worked well, but when I changed the feed to the signal from the underseat subs, I had to turn the gain on my amp down considerably!
The wiring is pretty simple if you have an average understanding of sound and follow the steps in the threads above.
1 - tap speaker level signal from underseat woofers
2 - convert to RCA signal through LOC
3 - plug RCA in amp
4 - run amplified signal to subwoofer