2012 gti stereo build

i picked up a new 2012 cw 4dr gti in june. i thought i'd be able to tolerate the factory system in a new car, i can't. :lol:

goals:
- keep the spare and as much of the trunk as possible
- reuse what i can, and go active. i've had horns+mids passive w/ a 4ch amp since like 1998. it's time for something different with a bit more power. i thought about going w/ mids and tweets but horns just kept beckoning
- use socket machine screws where possible so this meant t-nuts, hurricane nuts, and the like
- also wanted to try my hand at tech flex. all stuff i've never done before
- keep main fuses accessible
- finish before fall semester

also, i'm on afternoons this summer so i'm up until 4-5am every day. i tried to do as much as i could in the basement after work.

- factory RCD310
- audison bit ten
- soundstream ref2.640
- soundstream ref4.760
- selenium d2500 8ohm in ID mini horns under the dash
- idq62 midbasses in the doors
- arc audio black 10" d4
- knu 1/0ga and 4ga wire, 12ga speaker, signal wires
- about a roll of old school raamaudio
- a box of ss damplifier b-stock

i borrowed the trunk layout from here. i tried to get two 10" back there but ran out of room for other stuff.

prep stuff:
- modify screw-on horn driver adapters w/ 3-screw for 2-screw mounts
- stuff the horn bodies w/ reticulated foam
- connectors on stuff to make it easier to manage
- mounting rings





lined up nicely


try some foam inserts, patrick bateman style. foambymail.com is across town from me so i picked up some 1-1/2" thick reticulated foam








deans connectors, haven't used these since r/c cars when i was 13. midbasses are wired too but i'll upload pictures later.

i usually play with these kinds of routers, never worked w/ a wood router. usually did things carefully w/ a jigsaw in previous installs. :lol: i borrowed a plunge router, bought a circle jig and some bits, and played quite a bit.


3/4" mdf and 1/2" birch, roughed up and glued together.


on to the trunk. i built a template from the trunk foam and floor carpet, cut from there. built up the sub enclosure.


1/2" birch to drive the t-nuts into.


construction adhesive and a sheetmetal screw to hold the t-nut in


box together, definitely ratty. carpet right? :lol:. i'm terrible at box building. it's sealed and supported.


amp deck is hinged to get to the spare and stuff underneath.


t-nuts everywhere! notch at the bottom is for the seat belt mount.


seems like a great place to stuff a 5 farad cap. the lower level will also have small fusing and relays for remote turn-ons and lighting


test placement of the gear.

how the amp deck is mounted down in the back. the deck is notched to set down on the metal bracket and clear the nut.


planning for wire runs, philips screws are placeholders.






whew. take it all outside for a last fitting.


passenger side door skin is already deadened from the factory but i put some old raammat on it behind the speaker and on the inner door frame.

i put 2 sheets of damplifier on the back of the door panel/card. (pictures coming).

vagcom-coded and dropped in a set of door warning/puddle lights too; while it's apart right?

spent the afternoon on the car, passenger door is done.









door panel/card is deadened. trimmed back the plastic gasket around the speaker grille.





ready for the horns, started to tie everything down. signal wire from the HU down the passenger side with the speakers. i love the wire channels down the sides of this car.

time to start the driver's door. here's the mounting rings, covered in truck bed liner paint t-nuts for the driver mounting. typical for both sides.













ran all the wires to the back. driver's side has speaker and power wire. i ran a remote turn-on just in case. while lab'ing the bit ten, i couldn't get the speaker inputs to trigger the DSP to come on.



figured out where to mount the inline fuse holder


back to the hatch area, here's a shot of the fuses, relays, etc.


sanded down a ground spot in the hatch. covered it in dielectric grease.


deadener in the hatch.


i'll do the driver's door panel/card tonight.

props man looks intense..

Amazing build!

i went to install the driver's side midbass yesterday and heard some rattling. i got the object to be visible through the voice coil vent, seems to be the voice coil vent screen! it had fallen off!

with a hemostat and patience, i got it out.




driver door midbass mounted.


driver door panel deadened and trimmed like the passenger side. i did a layer of 3m super80 on the fabric so the deadener would stick and made sure at least 2 edges of the deadener would touch other deadener or plastic. i need to revisit the passenger side for consistency.



that's all i could get done today before work. it's too hot out w/o a garage.

JhnR said:

props man looks intense..

Click to expand...

swfloridamk6 said:

Amazing build!

Click to expand...

thanks!

removed the factory m6 bolt w/ a square head from the battery terminals. i replaced it w/ an m6x40mm flange head. i had to grind down one side to clear the terminal though.



mdf scrap workbench





ran 1/0 through a factory grommet in the bulkhead. pulled extra through and attached some split wireloom, it matches factory better.



same w/ the fuse holder end. nifty wire connector method but shitty fuse management. i'll never use this type of fuse holder again.



did the same thing for the ground wire, added a 1/0 wire to the body ground and battery.



everything fits, had to trim back the battery lid a bit for the ground wire though.



time to pin down the driver's side wiring..









i hope i never have to remove that back seat cushion again. ever. that's a huge pain to remove and install.

onto the horns! i think the car was made for them! there's so much room in the kick panels, not a bunch of stuff in the way for the mini horn driver location. i'll need to relocate the J1850 connector and footwell light on the driver's side, but it's pretty easy to remove.



i'll have to move the passenger side footwell light too. i put some old trunk carpet on the floor to catch the plastic shavings but i ran out of daylight to continue more.



none of the factory floor vents will be in the way, the horns will sit right at the bottom of the dash, tons of room.

tomorrow's plans are to finish the horn install, tap into the factory wires for DSP inputs, and install fuses.

got the horns mounted, stereo input leads installed, and fuses placed. also a bit of tuning!

didn't realize the one horn is bent, must have sagged over the years. the screws are countersunk now but not in these pictures.

the horns are mounted perpendicular with the seats and floor; the dash is curved. screws are 1/4"-20 socket head with lock nuts on the back side of the straps. more than enough foot clearance for pedals too!

the horn bodies look pretty beat up, i should paint them or get a new set of minis.





got the input levels set, gains set, crossovers set. so far things sound good. a buddy lended his ears tonight. i've got some sub level issues to sort out. horn channel output levels from the DSP are -13db from the midbasses and sub.

stage width is pillar to pillar, some lower frequencies get pulled to the doors. center isn't well planted yet.

i'll tune over the next week or so, get it all sorted out and familiarize myself with the DSP. then i'll pull it all out for carpet, paint, lights, and to finish the false floor. door sills and kick panels will go back in over the next couple days.

i played with the rta, then reference music, then production music. sounded muddy. today, i removed the reticulated foam from the horns, the top-end opened right up. i had to tune down some upper frequencies but i'm pretty happy with the sound.

stage width is pillar to pillar and depth is bottom of the windshield. stage height from the horns is face level, height from the midbasses rainbow a little. center is left of center. ears are drawn to localize the right horn, i've seen this in every car i've had horns in. 7 drum taps from the IASCA discs are good.

using the MFI to see volume numbers, i can see the RCD-310 starts to distort around 20.

i'm thinking about taping off the horn mouths, filling up the old holes, and painting the horn bodies in trunk liner paint (after roughing them up).

need to hook the cap up still, ran out of room in the 1-1/2" hole for another 1/0 wire.

started on the false floor today, took a template from the drop-in carpet.

broke my 1/4"-1" router bit.




fits!


cut holes for the amp grilles, so they can breathe. everything has a 1/2"-1/16" deep lip around the openings for grille metal.


countersunk the grille metal to avoid lumps in the carpet. held in with construction adhesive and screws.


same with the grill over the sub.


all the edges and grille metal have been painted in primer so they don't show through or rust.

cover the whole thing in trunk liner soon.

pulled the horns for filler, paint, and deadener

passenger side foot well light relocated to the blower motor, also one horn bracket


other horn bracket.


driver's side, bracket for relocated the datalink/j1850 connector+foot well light. also horn bracket. you can get to the datalink connector if you reach up behind the horn body.


old holes in the horn bodies are roughed up, fronts sanded, body filler added. first time playing w/ body filler.




ready for paint


painted with truck bedliner coating and then some dark gray primer.


passenger side horn reinstalled with kickspanels.


driver's side reinstalled with kickpanels.


debating on whether to order a box of black oxide screws, leave them the way they are, or paint them the same as the horns. meh. the horns aren't perfect but they look better than they did. they're still parallel with the floor and perpendicular from the seats, despite the dashboard. maybe i can fashion some grilles and attach them with magnets to the screw heads. we'll see.

pulled the hatch bits out for paint and carpet.

in case you wonder what the horns look like from the driver's seat, you can hardly see them but they sound amazing.