I was looking at adding some more to my stock Bose system in my '06 Coupe. First I dynamatted the crap out of my car (search for my previous post for details). That set a good foundation but I wanted crisper highs and mids so I replaced the front speakers with Infinity Kappa components. There are better speakers out there, but for $125 and being a direct 2 ohm replacement, the sound couldn't be beat. I thought I would be satisfied with that, but the bass from the 6x9's left sooooo much to be desired (couldn't really hear it when my windows are rolled down)! That's when my project started. After a LOT of research on these forums, I decided with the below:

G35 Coupe w/ Bose
Jl 500/1 Amp
JL 10W6v2
4080 Sub box
JL 4 gauge amp kit
JL Bass Control ****

Previously installed:
Sound dampening: Damplifier, Spectrum Sludge, and Overkill sound absorber (all from Second Skin).
Infinity Kappa Components from ebay.

I bought my JL components from ebay because they were SOOOO much cheaper. I just bought the extended warranty from Square Trade for the amp ($30 for 3 years). Contact 4080 for an awesome box and a great price!

 

The first step was to install the amp power wire. Removing the battery cover on the passenger side exposed the battery terminals and the large grommet that I needed to access. I removed the in-line fuse and disconnected the negative terminal of the battery for good measure. I connected the power wire with a round connector and made a hole in the grommet to run my 4 gauge wire through. This is best achieved by using a pair of scissors as the rubber is tough to stretch open. Once you have the correct length, make sure you put some silicone sealant on the grommet so you don't have any water leaking into that hole you made.

 

Underneath the glove compartment, you can pull straight down on the lower panel to expose your wire coming through. You also need to remove the door trim pieces and the kick panel to run your wire under the carpet.

 

As you approach the rear seat, you have to remove the bottom cushion by pulling straight up on each side. This allows you to continue to run your power wire to the trunk. Once you have the power wire running the way you want it, you can replace all the parts you had removed earlier.

The next step is to find the Bose amp underneath the trunk coverings on the driver's side. There are two harnesses that are running to the amp. The one you want is the blue harness. Remove that and identify your input wires:

Head Output Rear Right + Blue
Head Output Rear Right - Pink

Head Output Rear Left + Teal
Head Output Rear Left - Purple

Remote Wire Light Blue/ Silver

You need to be able to convert 18 gauge wires to an RCA jack to connect to the amp. One way was to get an RCA jack with a twisted pair of wires that you can cut and then splice. Another option is to get the JL line conversion that I used (pricey - $25, but I couldn't wait for mail-order). Splice them with in-line splicers available at Radio Shack and tape it up with electrical tape. You also want to splice into the Remote Wire for the amp. Although the JL amps have audio sensing power-on capability, it is unreliable (I found out the hard way) and I recommend using a direct remote power-on line.

 

The next step is to establish a ground for your amp. You need to attach it to the chassis and as close to the amp as possible. I found a spot that may not be ideal, but went ahead with it because I didn't want to drill into my car. There's a hole in the passenger side of the trunk that you can use as an anchor. Make sure that you sand all of the paint off it before you connect your ground.

** I will eventually redo this and use some self tapping screws to secure it to the chassis closer to the amp.

 

Once I had all of my wiring complete, I put all of the trunk coverings back together. I installed my W6 sub in the 4080 box with some 2" screws I bought at Home Depot. I had some issues with the fitment of the W6, but it sounds like it's an isolated problem. I turned it at an irregular angle to finally make it fit. I installed the box and laid all my wires inside the trunk. I connected all of the wires except the RCA plugs to the amp. I inserted the fuse near the battery, and THEN did I plug the RCA plugs in (the reason for waiting on the RCA's is to prevent the amp from attempting to ground through the RCA's to the head-unit, possibly damaging it).

 

I decided to install the optional JL Bass Control **** in the center console. I removed the felt covered top piece and drilled a hole in it. I also had to dremmel a bit of the console for the rear of the unit to fit. I ran the wire through the center console, under the driver's side seat and carpet, and pulled it through the door seal. I then ran it under the carpet and out the back to the trunk. I highly recommend this controller because it allows a great deal of on-the-fly control from inside your car once your have fine tuned your amp.

 

Connect everything up and 'voilà!' You should now have some very nice smooth bass. Don't forget to disconnect the rear 6x9's so they don't muddle your sound. I used electrical tape to tape the speaker harnesses down so they wouldn't rattle. I recommend playing with the amp settings quite a bit before you mount it to the backseat. This allows much more ease of access. Also, remember to close the trunk each time you change something so that you recreate how it will sound as you're driving. Also, remember it takes several hours of moderate sound levels to "break-in" your sub so take it easy. I used my fader to control my sub output and faded to the front at F3. This allows me to push my front aftermarket components with minimal interference from the stock rear speakers.

In retrospect, I probably would have went with the JL 250/1 and W3 combo and save some cash. My current setup is more than I could ever use, but I'm still very happy with it. I have the '06 with Bluetooth, so I don't want to go messing with the front amp any time soon. I would like to add an amp there, but I'm waiting for some brave soul to replace the bose amp altogether and preserve all of the features of the Bluetooth phone connection.

Feel free to add comments or question my install. I will edit it as necessary. Hopefully this helps out someone who was in my shoes but didn't know where to start. Here's a link to some reference material that may be useful:

http://www.g35frenzy.com/forum/showthread.php?t=1044

 

Nice write up!

 

Sweet...thanks for the write up...it looks a lot more complicated than I thought...I'm in the process of doing the same thing and probably will be using the same amp/sub combo...I'm still a newb to all the audio stuff though, so I'll probably be taking it to an installer.

Did you think about mounting the sub underneath near the spare tire? And is there a huge difference between what you have now compared to using the 250/1 and W3 combo?

 

BTW, the last 3 links you posted aren't working.

 

Did you just mount the amp directly onto the back of the seats? Or did you have install some sort of mdf board before the amp install? i'm still deciding where to put my amp. Not too sure if the back of the seats are sturdy enough for 2 amps.

 

looks complicated... i think im gonna get mine installed by a professional.. i don't trust myself.. lol good job though, ur trunk doesn't look all cooped up and it still has a nice clean look to it..

 

To tell you the truth, the install wasn't that bad. I just went slow and was meticulous with everything I did. As for the sound of the W3 vs the W6, I have not personally heard the W3's. My JL dealer told me that the W6 was the best at reproducing things such as snare drums, but also at delivering solid/tight bass in the lower frequencies.

The 4080 box is meant to slide in the corner of your trunk. It takes up a minimal amount of space and sounds great. I have seen custom boxes that go down under the trunk mat, but they are custom and are probably pretty $$$$$. The amp is mounted right on the back of the seat w/ some wood screws. I think one 500/1 amp is ok, but anything heavier might need some support.

Thanks for the heads up on the links... I'll have to search for them again and update accordingly. Let me know if you have any more questions.

 

Nice work. I've been using the auto-sensing turn-on and it hasn't given me any problems. What problems were you running in to? I'm very happy with my 250/1 and 10W3.