i have the pioneer gm-x802 amp with two 12in kicker subs. just ordered a new deck and two 6.5in speakers. the amp is only two channel. right now the subs are wired together as one. wondering if i should do the same with new speakers? would i then lose left right fade option? or not go through the amp for the speakers and use both channels of the amp for the subs individually?
Not only would you use the left right fade option, but you'd lose stereo sound. It would sound awful.
Just hook up the speakers to the head unit's internal amp or get another external amp.
If you wire a sub to each channel or both to one channel is all contingent on power handling and resistance. Sound won't differ unless you play them in stereo (and even that will have a negligible effect).