Replace factory sub JBL system!

Ok so I searched and searched and found small pieces of info here and there on how to tap into factory amp to add an amp and bigger sub with the factory upgraded JBL. Well here it is. What you will need:

1) New amp with "high level inputs" (hi low converter not needed. I chose Rockforg Fosgate r500x10 that came with a free wiring kit for $110 or so on ebay. )

2) a "add a fuse" mini low profile to connect remote wire to,

3) new sub enclose that fits without removing seatback plastic. Mr Marv made me a 10" sub box and amp rack to fit perfect on passenger side. This box was awesome and I do not have to remove my seat back. He custom made the box to my subwoofer specs and I used a 10" Pioneer shallow mount ts-sw2501s4.

Install:

To install your new amp I mounted my JBL factory amp and Fosgate amp on my amp rack. I then plugged all factory wires back into the JBL amp except the set of four wires plug. This is your subwoofer wires for factory amp. These wires are blue/red (right neg), blue/black (right pos), green/white(left neg) and green/yellow(left pos).

I took those wires and cut off the factory plug. These plugged into my new fosgate amp high level inputs. This replaces need for rca cables!

Now you have your audio feed to amp from stereo. Run your power and ground as you would any normal amp install. For the ground I removed the rear passenger seatbelt panel on wall, sanded a piece of metal down to bare metal, and grounded it using a 1/4" bolt and nut. This works great!

Now, the ever illusive REMOTE wire. Simple take your "add a fuse" and plug it into #4 of your under dash fuse. This add a fuse has a small wire hanging from it all ready to connect your remote wire to. So when you turn on car the remote sends signal to amp to turn on.

This is all there is to modifying the JBL to accept a bigger sub. One word of caution. I previously owned two 12's in my car. This 10" hits so loud it will make you deaf so no need for a 12 or 2 subs its already insane!

Notes:

Do not waste money on hi lo converter its unnecessary my system hits hard and clean! I highly recommend this amp kit on ebay. Any questions you can pm me.

 

Nice write up. I'm interested in upgrading to an aftermarket 8". Could I see pictures of your setup?

 

Subd for pictures

 

I've learned that if there are no pix then it didn't happen…lol

 

I'm with you on that but he's supposed to be emailing me pics. I'll post as soon as I get them

 

What he said

 

I am a little confused, can someone clarify something for me? This was adding a mono amp to the sub. What about an amp for the cabin speakers? I don't know if the factory amp is just for the sub or is it for the cabin speakers as well. Or are there two factory amps? Someone help.

 

Mr Marv just schooled me on this one: the JBL HU uses a low signal to the amp, the amp actively processes the signal & sends it out to ALL speakers SEPARATELY…only one amp

How'd I do?

 

So I can just take out the factory amp and add two new amps. One for the sub and one for the cabin speakers?

 

You'll need to leave in factory amp, tap into it's output to use for input into your other two amps. I am using the LC7i to convert mine before I run to my amps. In the middle of this now....

On a side note, I was surprised/disappointed that my rear JBL door speakers were ~2.5". wtf

 

Pics or it didn't happen!

 

Having new box built next week. The set up seems busy but I technically haven't lost any space over the factor sub....

 

how did you mount that lc7 to the back wall? as well as that memphis component(amplifier?).

 

I'll try to take a picture later, there is a small piece of wood that fills the gap. Ideally I would like to lose the memphis (for sub) and alpine (for components) and get a 5-channel amp. That would free up some room and I could upgrade to a 10" sub.

Also, I am having a better box built for the 8 that is in there. I went by the specs in the owners manual which called for .2-.3 cu/ft. Apparently there is a revised specs sheet RF released that says it actually should have .42cu/ft. Would have been nice to know before I built that box.....