Hi All, I've upgraded my stock 6 speaker (non-Sony) Sync system on my 2012 SE hatchback and hope this DIY thread helps future owners. If you have any questions at all, just ask and maybe I took a picture of it and can post it for you. I had to fight through some of it as there isn't a ton of info on our cars out there yet.
I kept the head unit as I really like the voice activated Sync features, blue tooth integration, USB port, etc. but added an amp to the hatch floor, single 10" sub in a small sealed box to give it some kick but take up minimal space (and be removable for loading stuff), replace all door speakers, and install a LOC in the glove box for easy access and sound control.
Here's the stuff I picked (I was on a tight budget and had roughly $500 of Crutchfield credits so I bought everything through them):
AudioControl LC6i 6-channel line output converter
Sound Ordnance M-4075 4-channel car amplifier
Kicker DS6.2 6-1/2" component speaker system
Kicker DS60 6-1/2" 2-way car speakers
Rockford Fosgate R1S410 Prime Series 10" 4-ohm subwoofer
Sound Ordnance Bass Bunker Sealed single 10" subwoofer enclosure
Amplifier fused power cable to the battery from the engine bay:
Amplifier fused power cable to the battery from the driver-side firewall. It took hours to find a spot to get through the firewall -- it's really congested back there. I think this pre-cut hole is where a clutch would go on the manual transmission cars.
Drilled firewall cover plate to pass the power cable:
Here is where I grabbed the 4 speaker outputs and power antenna feeding the LOC on the passenger side console wall. I found how to get the head unit out of the dash REALLY easily, but it's still easier getting the speaker-level wires up here than behind the head unit.
I used the 4 speaker wires and the power antenna to the LOC as follows:
Power Antenna YELLOW/ORANGE (+)
Left Front + WHITE
Left Front - WHITE/BROWN
Right Front + WHITE/PURPLE
Right Front - WHITE/ORANGE
Left Rear + BROWN/GREEN out of the HU, WHITE/GREEN back to the speaker (color changes at this connector)
Left Rear - BROWN/YELLOW
Right Rear + BROWN/WHITE
Right Rear - BROWN/BLUE
Where I grounded the LOC on the passenger front door sill:
The LC6i LOC in the glove box. I velcro taped it down so it can be pulled out and adjusted if necessary:
Note the exact arrow spot for where to press down to pry the little bolt cover off the door pull cover. It's the same on all 4 -- toward the back of the car. I pressed straight into the door pretty hard with a very small flat screw driver and they popped right out. I scraped the first one trying to find a good pry location, so lesson learned.
Front door handle trim piece pried off. After this trim piece is off, pry up the door switch unit to expose the bolts:
How to get the driver door panel off the car. Shows the bolt locations:
Here is the bolt on the outside door jamb of the front doors not shown in the above picture:
Here is a shot of the Kicker tweeter mounted PERFECTLY into the stock tweeter housing. I did snap off one of the plastic stems, and if you compare this picture you'll see what you would need to cut off. Snapped right in place with no trouble at all.
Here is what my Kicker components look mounted in the car. I put the crossover unit in a handy hollow location shown:
Here is the bolt locations for the rear doors (no side panel and bolt on the rears):
Here is the hatch with everything installed:
There is no visible equipment change except the sub in the hatch and the LOC in the glove box. Everything else looks exactly stock -- which was important to me -- and I have a toddler in the car a lot and didn't want him to accidentally grab a power wire to an amp under the seat, etc.
I ran power and power antenna to the hatch area along the driver floor, and the low-level RCA signals along the passenger floor. I grounded the amp by grinding off a nice clean patch of metal on the floor of the hatch and screwing an eye-connector to it with a couple of metal screws. I used the head unit power antenna to the LOC in the glove box, and the LOC "amp on" signal to the amp itself in the hatch area.
The system sounds vastly improved over stock. I'm still adjusting the sub cross-over point, amp gains, head unit settings, etc. but very pleased overall with the quality and it'll only get better when the speakers break in.
One last note: if you're thinking about upgrading the speakers using the stock non-Sony head unit, forget about it. The head unit is incredibly underpowered and the sound will get worse, not better. Keep the stock speakers if you don't add some power or swap head units. Hope that saves someone some time!
I can't think of anything else interesting to note. Hope this thread helps someone in the future!