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Alright guys! For those of you with factory sub and amp combo like me, I have a cool new upgrade. Get rid of the factory sub and amp for some sweet JL stuff!

A while back I sound deadened the doors and back wall of my truck. Not necessarily for better sound from the sub as much as I wanted to quiet down the cab a bit. Side effects were definitely better sound though as well. So, since I was going to do this sub and amp upgrade, I decided to pull the back seat and go to town.

I finished the floor and C pillars with Raam mat dampener and sound barrier before I started with my sub install.

This is the floor before I added anything.

And here it is after the dampener and covered in sound barrier. It makes a pretty good difference in road noise, exhaust sound, etc. I like the inside of my truck QUIET.

Now onto the good stuff.

Here is the factory sub and box. The amp is tiny and mounted to the back of the box itself. Pretty slick deal, and works well for what it is. Like most of us here, I wanted just a little more without giving up the factory fit and finish of this set up though. (Don't mind the dust. lol)

I started by pulling the box out... It's 5 bolts and a plug. Super simple.

Now for disassembly of the box and retro fitting of the new sub.

The screws holding the stock sub in the box are all T20 torx. Pull all those and you can just unplug the wires in the back of the sub.

To adapt our new sub to the box, and provide some of the clearance that the deeper sub needs, we add this sweet billet ring, and take a dremel or whiz wheel to the ribs in the back of the box. Here you can see where I clearanced the ribs.

You use the stock torx bolts from the old sub to fasten it on. Also - use some ultra gray RTV or something similar between the ring and the box. The ring comes with new allen bolts to attach the sub to it.

Since the new sub doesn't use these plugs, and also only has 1 port for positive and negative, I twisted the two positives and negatives together.

The stock box has a harness that exits through a grommet in the back. Here is a picture before I cut the plug off to splice to my speaker wire once it's in the truck. Don't forget to twist these two together if you twisted the other ends together. Two are marked with a white tracer to make things easier.

And now, we are ready for the new sub! Looks way sweeter than stock!

Plug it in and screw it down to the billet ring.

Now we are ready to wire the amp and everything else in! Starting with power, take the power lead from the battery and run it through the firewall. In my case, I went through the passenger side. It was a pain to find the wire I pushed through inside the cab. Look for the blue wire. It's hidden behind a bunch of junk. Also, now is a good time to stuff some sound barrier up onto the firewall. :D

One thing that I really like about these trucks is the wire tray that runs the edge of the cab front to rear. Makes laying wire like this super simple.

Now that we have power to the back, we will tackle getting our crossover wired in. The crossover is what is going to give our new sub a signal from the stock system. Luckily, we can take it from the speaker in the c pillar. In mine, the 2 orange wires are the signal that I needed. They are positive and negative; again the negative wire has the tracer.

Now, we have to wire these in to the corresponding inputs on our crossover. I also took this opportunity to add sound deadener to the C pillar! I mounted the crossover inside of the C pillar too. Now we can plug the RCA's into the crossover and leave them out to plug into the amp.

The crossover will have 3 wires running to the amp in addition to the RCA cables. The 3 wires are remote: Signal for the amp to turn on, then just power and ground. I ran black wires for all 3 just so they blended in. I also took the ground for the amp from a seatbelt bolt on the c pillar, behind the cover.

Pay close attention to the speaker wires on the amp. Notice that they are bridged. This essentially means that we are only using one channel of the available 2 channels on this amp. These wires are what you splice into the back of your sub box where we cut the plug off.

The very last thing is hooking up the RCA cables from the crossover to the amp and then tuning the amp. This sub runs best between 80 and 100hz. On the deck, turn the bass down and tune it to your liking!

I have had this for a couple days now and it's AWESOME! It is perfect for guys looking for the next level from their stock sound systems.

Professional American, guarding our constitution.
9,453 Posts
You realize by splicing into one speaker to supply your x-over you've created an unbalanced load on your head unit (stock, I'd guess, and that's a whole other rant) that will eventually cook it?

Notice how your bass fades as your volume increases and you have to compensate with either the remote gain on the JX or if the x-over has a remote?

Also, even though you have a x-over filtering out the higher freq's in the RCA's, it wouldnt hurt to slide the filter switch on the JX to Low Pass... I see you set the filter to 100Hz but you also have to tell the amp whether to cut off above or below that frequency, and that's the difference between 'HP' and 'LP'

Lastly, you know you're feeding a 250RMS watt sub with 360RMS of noise-laden power (because of the speaker level inputs) out of that JL amp, and JL's are notorious for being underrated... More like probably 425RMS comes out of that amp and thats on a groggy morning...

Just sayin...
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