Just completed an amplifier and speaker upgrade on my 2013 C6 GS convertible – including installing upgraded speaker wire to all the new speakers (had left over home theater 16-gauge wire). I did not upgrade or amplify the dash tweeters or center speaker. I also kept the Bose Premium HU with Nav because I wanted to keep the OEM radio look. It sounds great with the new amps and speakers - I am sure a new HU would sound better and offer better features. I did not have to remove anything but the passenger seat and the plastic rails along the carpet and rear door pillar (which I broke off a clip by pulling it toward the door instead of toward the trunk - lessons learned. JB Weld Epoxy worked well to adhere it back on).

I purchased everything from Crutchfield for around $2500 and did entire install myself because I knew I would treat my car with kid gloves. Here is a comprehensive list of equipment:

AMPS

- Rockford Fosgate TM400X4AD 4-Channel Amp (used marine type because of sale price)

- Rockford Fosgate T750X1BD Mono Amp

- Rockford Fosgate PLC2 amp remote

AMP WIRING

- Crutchfield CK8 Amp Wiring Kit (one kit is all you need if you place amps where I did)

- Crutchfield 8-gauge Black Ground Wire, 5-feet (the 17" piece from the CK8 kit was not long enough for both amps)

- Install Bay Ferrules, 8-gauge, 5-pack (to attach the positive wires to the fuse blocks; does not fit in the RF amp plugs)

- EFX DFB4 Delta Fuse Block

- T-Spec V8 Mini-ANL Fuses, 60-Amp, 2-pack

- T-Spec V8 Mini-ANL Fuses, 80-Amp, 2-pack

- JL Audio XD-CLRAIC2-SW, 2-Ch speaker-to-RCA Cables

- EFX 2-Ch RCA Patch Cable, 3-foot

SPEAKERS

- JL Audio C2650, 6.5” Component Speakers, Door

- JL Audio C2-525X 5.25” Speakers, Rear

- Kicker 46CWTB84, 8” Bass Tube, 4-Ohm (Qty. 2)

- Metra 82-3014 Speaker Mounting Brackets, Door

- Stinger Roadkill RKFR6 FAST Rings, Door

- Dynamat 10415 Xtreme Speaker Kit, Door

- Install Bay SPHKC Speaker Installation Kit, Door

MISC

- TICONN Solder & Seal Wire Connectors (Amazon)

- Auto Craft Heat Shrink Tubing Set (Harbor Freight)

- TKDMR Marine Grade Copper Wire Lugs, 8-gauge with 5/16” hole (Amazon)

- Steinel 07051 39mm Reflector Nozzle for Heat Gun (Amazon)

- Door Trim Panel Retainer, 15-pack, Clips And Fasteners Inc, GM 10350983 (Amazon)

- Simpson Strong Tie, 12”, MSTA12Z (Qty 3, Home Depot)

Many people deleted the rear speakers, but I feel they add for a fuller sound, especially with the top down. Installing those are straightforward, but I ran new speaker wire for those since the rear factory wiring was in parallel. I rewired them so they would be in stereo.
I also installed two (2) Kicker 8” bass tubes because I wanted the best sound in the smallest package. They are tight and sound excellent and I can crank up the radio without them distorting. Therefore, I ran new speaker wire for the rears and subs up the passenger side and passed through to the trunk compartment – underneath the carpet behind the seat and trunk. I screwed the bass tube mounts into the rear compartment covers so I can remove the tubes easily out the mounts to open the compartments.





I mounted the mono-amp right behind the passenger seat. I chose this amp because it is very small, super easy to set up, has a subsonic filter, and is 600 Watts into 2 Ohms. I didn’t secure the amp to anything other than to put a small strip of 3M double-sided tape to the carpet.




With regards to mounting the 6.5” mid in the door where the factory sub was easy - with the free Metra speaker mounting bracket. I installed the Stinger Roadkill foam on the door directly behind the mid, and it did not interfere with the window. I ran the thin gasket from the Install Bay kit on the door to create a seal between the Metra bracket and the speaker opening. I cut out the Dynamat to install between the Metra bracket and the 6.5” mid speaker.
The tweeter took more work because I had to make my own plastic bracket to mount in the door top location. The JL crossover is big so the only place I could mount it was on the door panel and not the door, which is a pain and not ideal. I took a small hacksaw blade and cut out a 1” deep Styrofoam piece from the door panel and used construction glue and screws to mount the crossover.

I ran the mid and tweeter speaker wires behind the door and out the large rubber cover. Make sure you have a box of door panel retainers because I had 3 that were broke. I put a few pieces of left over dynamat on the wiring to secure it to the door.




Running the new speaker cable from the door to the amp location was a pain because I could not fish it through the existing route. You need to unseat the rubber conduit between the door and frame on both ends and use your fingers to push the speaker wire through. I went from the interior to the door. I carefully drilled a hole in a plastic cover (right above the hood release latch) that was in line with the rubber door conduit.




To get from the driver side to the passenger side (where I mounted the 4-ch amp), I ran the cable through a small passage as shown below (see white wire). It is very tight but you can do it when you find it.



I mounted the 4-channel amp in the location where the Bose amp was. I used 12” metal straps you find at Home Depot and measured them to secure the amp and mount to the existing holes. For the top 2 brackets, the lines are for the bends; for the bottom bracket, that is where I shortened it.





Again, I chose the Rockford Fosgate amp shown because it fits perfectly in that area. However, it is a PITA working in that small area under the glove box but that allowed me to make short connections from the factory radio low level inputs to the amp inputs. I used the solder and seal connectors instead of the crimp connectors because I knew there would be a lot of cable movement to get the amp in location and solder is the most secure. I slipped on an extra heat shrink tube up the wiring and then shrunk over the connectors as extra protection. I bought a special attachment for the end of the heat gun to allow the heat to get all around the connector because twisting it would be a PITA under the glove box. It takes more time, but I never wanted a chance of having a loose connection.






For the amps' power, I removed the battery and drilled holes in the fiberglass behind the battery platform (see photo below). It is a great place because the power wires drop right behind the passenger floorboard fuse box. Below shows one 8-ga wire but you can easily fit 2 or 3.





I installed some sticky back behind the battery and other locations to secure the power wiring out of the way of the battery so removal is easy.



I mounted the fuse blocks on the sidewall in the engine compartment and terminated on the main (+) input in the engine compartment fuse box.



That is pretty much it. If I had to do it over, I could probably do the entire install in half the time. If anyone has any questions or needs assistance (especially if you live in Louisiana), I would be happy to help out.

Here are the speakers I removed when upgrading. If anyone is interested in any, you can have them for free if you pay for the shipping which should be about $15-$25.

 

Great write up, thanks for sharing

 

I haven't seen bass tubes since my bazooka days in high school, wow.

 

Thanks for taking the time to not only describe exactly what you were doing but also for taking pictures.