Upgrading the Mk7 Fender audio system - Build Log

[echosix]

I've had my GTI for about 4 years now, and while I don't hate the Fender system, it's time to upgrade. I used to do a little custom car audio back in the day, so I hope I remember how to do some of it! My buddy (also a former car audio installer) and I started on this build a few days ago, but only have a few hours after work each day to mess with it. I expect we will be done this weekend or early next week. I'll update as we make progress.

Here's a picture of Chuy from the outside --> illegal tint and new shoes

Credit where credit is due: I need to send a big shoutout to the guys who did all this work documenting the pinouts and connections for us already!
--> THIS THREAD for the MIB2 pinouts and VCDS coding,
--> and THIS THREAD for the fender amp pinouts

The Fender system is better than a lot of stock systems I've had, but it can't compete with aftermarket gear. Here's what we're going to install:
- Focal 165AS 6.5" components in all four doors
- JL 10" W3v3 DVC 2ohm
- JL 400/4 (75w x 4 @ 4ohm)
- JL 500/1 (500w x 1 @ 2ohm)
- AudioControl LC7i line out converter


First things first: the design.
Like one of the threads linked above, we're going to tap into the back of the MIB2 head unit and recode the system to send speaker level signal out the unused pins. I ordered the missing 8-pin quadlock connector from ECS, but it does NOT come with the pins. After quite a bit of searching and cross-referencing part numbers, I ordered the terminal pins to go in that connector from Mouser. These are the right pins to go in the brown connector:

The signal flow will be:
MIB2 speaker level output -> LC7i LOC -> JL 4-channel and sub amp -> Focal crossovers -> OEM Fender amp harness -> Focal component speakers

Wiring diagram:

Laying everything out in Sketchup:

I originally planned to put RGB edge-lit lexan panels on top of the amps, but decided to scrap that idea and inset the amps a little in the facade instead. I may revisit the idea later.

On to the actual disassembly. We removed seats and all the trim so we could lay sound deadening on as much surface area as possible. The road noise in the mk7 is deafening at highway speeds and it's one of the very few things I dislike about the GTI. I've been wanting to do this for a long time.

The 0ga power wire was way easier to run than I expected. There's already a cutout in the firewall that nothing runs through. The insulation is perforated and popped out as soon as I touched it. Of course the hole is too big, so I'll have to seal it up when we're closer to done. The wire fits nicely in the door sill channel. We're going to fill in a little more killmat in the bare spots today, run the speaker wires, and then start to reassemble the interior. I put sound deadening on the inside of the hatch too, but I didn't take any pics before putting the trim back on.

Test fitting the sealed box. I had a design for a ported box as well, but it was going to be a challenge to stuff a box with that much internal volume in here and still keep the factory floor panel. I want this all to fit under that flooring, so the smaller sealed enclosure won. I used a router to carve out a 1/2" deep indentation on the bottom to accommodate the steel fixture where the spare tire stud locks in.

Test fitting the amp rack and facade/box top. We used CAD (cardboard aided design) to transfer the basic shape of the area to the MDF. There was a LOT of put it in - mark it - take it out - trim it - put it in steps here, but all worth it in the end. I like how it came out.

I mounted the crossovers on the amp rack and started running speaker wires this morning, but had to stop and do my real job. Updates to come later this weekend!

 

[echosix]

Holy cow, this is more work than I remember. And laying on the floorboard of a car, soldering wires hurts a lot more than it did 20 years ago! We got most of the tedious stuff done this weekend, and we're in the home stretch. If the pins for the head unit connector show up today, we might get to hear it later tonight.

- 0ga power from the battery wired to the new battery terminal, and connected to a distribution block mounted under the amp rack. Drilled a hole in the side of the spare tire well and installed a rivnut for the ground wires from both amps.

- My buddy showed up with 12v LEDs, so I guess we're putting those in after all. I ran 12v, ground, and remote-on wires from one of the amps to a 4-pin relay that I mounted under the amp rack. This will give us a 12v lead that will turn on the LEDs when the amps are on.

- Ran 4 pairs of 18ga speaker wire down the passenger side to connect the speaker-level out from the MIB2 head unit to the ch1 & ch2 inputs of the Line Out Converter. The LC7i will sum the inputs to provide 3 line-level output channels (3 pairs of RCAs). Channels 1 & 2 go to the 4-channel JL amp, Channel 3 goes to the subwoofer amp.

- Ran 8 pairs of 18ga speaker wire from the crossovers down to the factory amp location under the driver's seat. Using the pinouts from one of the other threads, we tied these to the factory harness to provide signal to the door speakers without trying to run speaker wire through the door loom.

- Removed the A-pillars and installed the new tweeters. It is absolutely terrifying how hard you have to pull on these things to remove them. We debated on install method and decided just to hot glue the new tweeters in. They seem really solid, but we'll keep an eye on them.

- Made adapter rings for the door woofers and installed the speakers. The factory speakers in the front doors are dual voice coil. The aftermarket woofers are not, so I picked one pair of wires at the amp harness (there's a woofer 1 pair and woofer 2 pair) to use for the new woofer. I cut off the factory connectors to clean it up (don't judge me lol)

- We also got the tweeters mounted in the rear door cards with some metal strap wedged between the door card insulation and the factory tweeter grill (I'll snap a picture later). This worked a lot better than we expected it to.

 

[ZERO815]

Respect. I have been there 25 years ago . However just one side note, many MK7/MK7.5 suffer from a leak at the rear and some at the front speakers. Water runs on the inside of the metal door skin. Make sure your wooden adapter rings don’t act as a sponge.

 

[Cuzoe]

Respect. I have been there 25 years ago . However just one side note, many MK7/MK7.5 suffer from a leak at the rear and some at the front speakers. Water runs on the inside of the metal door skin. Make sure your wooden adapter rings don’t act as a sponge.

Can confirm, found some rust on the terminal screws of my passenger door speaker last time I was in there. Driver side was okay... but yes water gets in there.

 

[echosix]

Respect. I have been there 25 years ago . However just one side note, many MK7/MK7.5 suffer from a leak at the rear and some at the front speakers. Water runs on the inside of the metal door skin. Make sure your wooden adapter rings don’t act as a sponge.

Good looking out. How is water getting inside the door? Are the seals worn, or were they not sufficient from the factory?

 

[echosix]

The pins came in for the MIB2 connector, and they were a perfect fit! (original post updated with part number from Mouser). I made a harness and fished it up the kick panel to the back of the slot where the head unit installs. I crimped the pins on each wire, soldered the connection, heat shrink wrapped each one and carefully slid each into the correct hole on the connector.

We used VCDS to recode the radio to send speaker level outputs via these pins. I did NOT use the same 2ch/4passive speaker setting referenced in the other thread. You can get away with running two pairs of wires to your LOC and bridging the inputs, but you will lose fade control at the head unit. I tied into all four channels, so in VCDS I chose the 4ch/8 passive speakers option.


Permanently attached the subwoofer box to the top panel, carpeted the panel and put it in place. The carpet isn't a perfect match, but it was $12 for a 72"x36" piece from O'Reilly's and they had it in stock - it's close enough. I used a way-too-long piece of 12ga speaker wire from the mono amp to the sub box so I can pull the top panel and sub out all together and still be able to keep it connected while I mess with the controls on the amps.

The goal was to make this all fit under the stock floor panel... mission accomplished.

We got it all tuned and oh man, it is so loud and sounds so good! It shakes the mirrors (and even your vision when it's turned up) and you can feel the sub when it hits. Despite that, nothing rattles with all the sound deadening we put in. Overall, I'm really happy with how it came out. Just need to reattach the A-pillars, a thorough detailing of the interior, and it's done!

Lessons learned:
- Get extra trim clips (metal ones for the A-pillars, and the weird spiral ones for the door panels). You're going to break them.
- Connect a battery charger. VW's freak the hell out throwing codes and errors if you try to crank it when the battery is low.
- When troubleshooting, remember Occam's Razor. It is usually something stupid, like you forgot the terminal cup on the sub box is fused until after you've spent 45 minutes troubleshooting why the sub doesn't work.
- Fabric tape is awesome and makes your harnesses look OEM
- Use the reboot. Like your home PC, sometimes turning everything off, disconnecting power, and turning it back on will fix it.

 

[username205]

That turned out really nice! I’m guessing those JL amps are fairly efficient and won’t have any overheating issues while sandwiched between MDF? I’m still trying to figure out how my amp and DSP will be installed/displayed.

I bought that exact same carpet from O'Reilly's but haven’t installed it, so it’s a relief to see that it’s a very close match

 

[ZERO815]

Good looking out. How is water getting inside the door? Are the seals worn, or were they not sufficient from the factory?

Water gets into the door between glass and seals. It's designed to go that way and leave the door through holes at the under side.

 

[DangerDane2008]

Come do this to mine when you’re done. Fantastic work.

Does the sounds deadener work well in the back? I’ve noticed my wagon has quite a bit of road noise on the interstate and most of it seems to be from the back.

 

[echosix]

That turned out really nice! I’m guessing those JL amps are fairly efficient and won’t have any overheating issues while sandwiched between MDF? I’m still trying to figure out how my amp and DSP will be installed/displayed.

I bought that exact same carpet from O'Reilly's but haven’t installed it, so it’s a relief to see that it’s a very close match

Thanks! The amps are class D, which generate very little heat. Even so, there's about 2" of space between the MDF amp rack and the top panel, so they're getting some air.

The old class A & B amps had to be mounted horizontal so the heatsinks would work, and you had to allow for plenty of air circulation - those were such a PITA... we even put computer fans in sometimes to keep them cool.

Water gets into the door between glass and seals. It's designed to go that way and leave the door through holes at the under side.

Oh, so it's working as intended? That's super interesting. I'll keep an eye on the speaker rings. Thanks for the tip!

Come do this to mine when you’re done. Fantastic work.

Does the sounds deadener work well in the back? I’ve noticed my wagon has quite a bit of road noise on the interstate and most of it seems to be from the back.

Thanks! So far the sound deadener seems to be working really well, but I haven't ridden in the back of my car... like ever, I think. I'll have to give that a try. Aside from the reduction of road noise, I was pleasantly surprised to find how effective it is at keeping things from rattling. These cars have a lot of interior parts that rattle right from the factory, and this seems to have cured all of it.

 

[DangerDane2008]

Thanks! The amps are class D, which generate very little heat. Even so, there's about 2" of space between the MDF amp rack and the top panel, so they're getting some air.

The old class A & B amps had to be mounted horizontal so the heatsinks would work, and you had to allow for plenty of air circulation - those were such a PITA... we even put computer fans in sometimes to keep them cool.


Oh, so it's working as intended? That's super interesting. I'll keep an eye on the speaker rings. Thanks for the tip!


Thanks! So far the sound deadener seems to be working really well, but I haven't ridden in the back of my car... like ever, I think. I'll have to give that a try. Aside from the reduction of road noise, I was pleasantly surprised to find how effective it is at keeping things from rattling. These cars have a lot of interior parts that rattle right from the factory, and this seems to have cured all of it.

I’ve never been in the back of mine either but there’s a lot more area in the back of the wagon vs gti and I think it just echos more back there. I need to take a weekend to do this. What did you buy and how much square footage

 

[c31561]

Awesome work, I did similar to my standard radio a few years ago. Sounds so much better than stock. I like that software you mentioned, I plan to try it out.

 

[echosix]

I’ve never been in the back of mine either but there’s a lot more area in the back of the wagon vs gti and I think it just echos more back there. I need to take a weekend to do this. What did you buy and how much square footag

The sound deadening is Kilmat. I bought a 36 sqft box of 80 mil and a 50 sqft box of 50 mil. We did the entire car with the 80 mil and didn't use the entire box or even open the box of 50 mil.

 

[turbovw1]

How different are the Focal 165AS and the Focal VW 155 kit?

Which is better?

 

[echosix]

I went into Car Toys to listen to some Focal and a few other brands side by side. The salesman showed me the specs on the VW kit that Focal makes and said he could order them, they sound very similar to the 165AS, and were the same price. They are in a housing that is designed to install right into the GTI factory locations and plug into the factory harness without any adapters. I would have ordered the VW kit right there in the store, but the guy had an attitude the whole time I was in there, basically telling me I didn't know what I was doing and I wouldn't be able to make the 165AS fit in a Golf because it wouldn't clear the window hardware, etc., etc. I didn't argue with him about it. I just listened to the speakers I wanted to hear and left without buying anything. I thought the 165AS components sounded the best out of anything on their display, including the ES 165k sitting next to them.

Without hearing them side by side, I assume the only tangible difference is the VW kit is way easier to install, and I'm pretty sure I only went with the 165AS just to prove that I could.