[ctuna]

Weren't you on here awhile ago making all kinds of changes
to your system and not really being satisfied with any of them?
If your pre outs from the head unit are attached to a Technic Hi Fi
Harness the xd/600 splits the front channel signal and routes
a pair of channels to the doors and a pair to the floors if whoever
wired it in did the job correctly.
Being able to do this stuff yourself is the only way to guarantee
you got what you expect.
I thought you bought a bunch of audison stuff.
Had somebody install it and audison actually tuned it.
If its the typical bass head install they bypass the underseats.