Step 4: Now, let's install the speaker wire to RCA converter
- Here's your factory subwoofer wiring harness. It has 5 wires on it. Power +, Ground -, and a 5V Remote Turn on wire(no, you can't use this for your new amp's turn on wire), and 2 Low Voltage speaker leads. Green/White is POSITIVE +, Purple/Green is NEGATIVE -!
- I simply cut and stripped the 2 speaker wires, and left enough room on the harness side so I could reconnect the wiring in the future if needed. Now just isolate those 2 speaker wires and get the rest of the harness out of your way. Stuff it under the carpet or something.
- Make your + / - connections to your RCA adapter - OBSERVE POLARITY. I only used 1 "side" of the RCA plug, since 1 set of speaker leads is meant for 1 single RCA plug. We will use the Y-adapter later to give us our L/R dual RCA connections(which isn't entirely necessary by the way since it's a MONO subwoofer amp you don't need 2 channels L/R, but it makes the installation look cleaner and JL Audio recommends connecting both the L/R to your amp to avoid having to raise the input sensitivity level due to loss of signal).
- I decided to solder my RCA connections to the stock wires because I think splice connections and butt connectors fall under the
hack category.
- Alright, so clean those connections up, heat shrink/tape the connections separately and stuff the rest under the carpet. Install your RCA Y-Adapter and bingo, you're done!
- Oh and the floor mat covers that ground connection too - stuff that's this easy kind of gives you a warm fuzzy feeling inside doesn't it?
Step 5: Connect your accessory TAPA CIRCUIT and remote turn-on wire.
This is pretty straight forward, just choose a fuse that is powered on with the ignition and tap off it. I used the fuse # 46 7.5A Occupant Sensor. I used this because it only powers on with the ignition in the RUN position. You probably don't want your amp turning on in the ON position because it can seriously drain your battery. Ideally, you just want the amp on when the truck is running. Now if I am sitting idle, with just the radio ON or working off Accessory Delay, my subs are not running and draining my battery.
- All you have to do is cut/strip/crimp the wire you ran earlier to the TAPA CIRCUIT pig tail. Install the fuse block to your chosen location, reinstall the "stock accessory" fuse and your new accessory fuse in to the block.
Step 6: Put all your panels back in place. Get ready to finish up, and hook up the amp!
- Make sure all of your wires - Power, ground, remote turn on and +/- speaker leads are cut to an appropriate length and strip the ends. Observe speaker wire polarity.
- Hook up your wires and make sure stuff is TIGHT. Loose wires blow fuses and start electrical fires! Blown fuses wait for you in HELL!
- At this point I have not come up with a logical way to mount the amp other than using Velcro strips on the amp and securing it to the floor carpet. It will secure the amp sufficiently for daily driving but will not protect against theft or heavy off roading. Use ties to clean your wiring up(not shown-sorry about the mess).
- Remove your spare tire kit - sorry but you won't fit a reasonable sub enclosure without removing it. I'll post my solution for storing the spare tire kit and jack at a later date.
- Hook up your sub wires - observe polarity.
- Place the box under the seat!
Tight Fit!
-Ok, all your connections are tight? Put the inline fuse in its holder and hook up your Negative Battery Terminal.
Now, last but not least you MUST tune your amp! You should refer to your amp's owner's manual for proper adjustment of gain/input sens, crossover frequency and bass boost. My JL Amp has adjustments for Low-High Input Voltage to maximize input signal sensitivity without clipping.
I set my input sens adjustment to "Low", and tested the AC(YES, AC not DC!) voltage at my amp +/- speaker terminals with the sub disconnected. Using the instructions provided in the installation manual, I used a 50hz SINE WAVE test tone (+0db) I downloaded and played to adjust my output voltage at my speaker leads to 31.6V as recommended by JL for a 4ohm subwoofer. From there, you can adjust the additional crossovers and bass boost adjustments according to your music taste and preference/acoustics.
That's about it!
I rate this sub/amp combo at:
Stock
Some added bass
A Little Kick
-> Mirror shaking
Wakes the neighbors up
Will make your ears bleed
Glass Shattering
Overall, I am very happy with the JL Audio amp/sub combo. JL Audio has a reputation for high quality car audio components and generally speaking you cannot go wrong with JL. I was pleasantly surprised at how loud this little 10" sub is and how clean the amp is. It's louder than I expected and I have heard dual 10" subwoofer installations that weren't this loud. The amp is clean and responsive, providing quick, tight, punchy bass while listening to hard rock/metal/techno. This sub will also make your hair move a little bit if you listen to something with more bass such as Rap/Hip Hop.
VIDEOS
Showing how quick, responsive and clean the setup is listening to Pantera
. The double bass sections are reproduced accurately and without any slop. It should also be noted that a sealed enclosure is ideal for rock/metal music because it will produce a tighter sound. The sub's response to the double bass drum section @ :36 is very impressive IMO.
This video is the best I could come up with to translate exactly how loud the sub is, and how much it shakes the truck. Can the stock sub do this? Absolutely NOT. It's making a lighter dance across my center console...
. 
Linear Mode
