2000 LS stock Head unit sub/amp install?

[Janobala]

I got this: MTX TNP112D 12" Subwoofer And 200W Amplifier https://www.amazon.com/dp/B00318KAGM/ref=cm_sw_r_awd_sJcSub0H89MW5

I want to install this to the stock head unit, so please don't tell me to get an aftermarket head unit. I have the premium audio alpine system. (XW4F-18C870-BK) my first question is about a hookup on the rear of this head unit, there is a square opening with the word "amp" inside of it, but it appears as it is just a blank opening, I do not see any sort of connectors inside this space?? What is this for? If I want to hook up my sub should I disconnect the speakers that are behind the rear seats and replace that connection with the new amp? If so do I need a adapter to plug into the head unit to run to my new amp? Just need some guidance of how to go about getting my system hooked up to the stock unit. Thanks for any help!

 

[joegr]

"AMP" is the brand of the connector on the back of the radio. (Since the radio was made, AMP became Tyco, and Tyco is now TE Connectivity. I think that the AMP brand name is still used by them for some of the connectors.) Anyway, that has nothing to do with any radio amplifier.

Those are 6x9 subs behind the rear seats (the rear speakers are in the rear doors). The factory sub amp is located between the two subs, on the bottom side of the package tray in the trunk. A mono, line-level differential audio signal runs from the headunit to the amp, along with a seven volt or so turn-on signal for the amp. Your amp may work with a 7V turn-on signal. If not, you'll have to add a relay. I think that some on here have use the differential signal as a single-ended one (what your amp requires) without problems.

 

[Janobala]

So if I install a sub in my trunk the little subs in the rear deck will not really add anything to my system correct? So may as well disconnect them? The amp I want to put in used rca cables? So do I get an adapter for the output in the head unit that will have rca on the other end to plug into the new amp?

 

[joegr]

Yes, if you are adding aftermarket subs, then there's not much point in leaving the factory subs. More to that point, I'd bet that the foam on your factory subs has all rotted away anyhow.

I don't think they make wiring harness adapters that work in that direction: factory head unit -> aftermarket amp. I'd not mess with the head unit and the wiring up front at all. The signals that you need are already in the trunk at the factory sub amp. Why not get them there? You'll have to solder an RCA on to the factory wires.

 

[joegr]

These search results may help: https://www.google.com/search?hl=en...mages&tbs=&as_filetype=&as_rights=&gws_rd=ssl

Note that the headunit wiring/connectors is different between 1st and 2nd generation LSes. However, the wiring/connector at the sub amp in the trunk seems to be the same for both generations.

Pin-out at the amp in the trunk.
Pin 1 is the amp enable ("turn-on") wire, yellow/red
Pin 2 is power ground, black, or some times black/blue.
Pin 5 is constant power, red/blue.
Pin 7 is positive audio in, white/red.
Pin 8 is negative audio (ground) in, gray/red.
Pin 9 is the uninsulated audio shield wire (a ground).

 

[Janobala]

Thanks a ton, you've been a big help, I think we got our plan on how to hook it up now.