Car Stereo Installation

[imcarthur]

First of all, a note to all who belong to the so-called "Church of Weight and Speed', whose goal is to reduce weight on their 911: Go for it guys. Strip it down, throw stuff out, have fun. Go build the ultimate 911 light-weight go-cart. It's not what I want.

While I'm at it, I might as well address those 911 owners who feel that the sound of the Porsche flat 6 is better than Mozart: I don't care. My car is a cruiser & I wanted a decent sound system. As for the flat 6? Yes, it's great. I love it, too. But on a freeway? At a constant 70 mph? Give me a break, it gets tiresome. Live with it if you want to, but I'd rather have Bob Marley along for those drives.

After a lot of forum post reading & talking with some of my customers & suppliers who dip into 12V hi-fi, I decided on a basic system:



Head Unit: Dual XD622W - AM/FM/CD Weather Receiver - Somebody posted this one a while ago. Plain faceplate. No damn light show & a simple muted inoffensive green glow. It has a volume knob rather than stupid buttons. And not being a fan of compression & MP3s, these backwards leaning 'features' were also not in the mix, although there are RCAs for an Aux input for the future. If you start with poor quality media your system can play nothing but poor quality & lossless compression ain't lossless.



Door speakers: Focal 165V1 - 2 Way Component System - I sell Focal home product & I know & trust their sound. And I could buy it for a very good price since I work remotely with the factory staff. This series is a midrange series for Focal in technical terms.



Amplifier: Focal 2.75 - 2 x 75W rms 4 ohm new premium series of amplifiers from Focal. Big. Hefty. A real amp rather than the cheapo Class D things from other vendors. Class D is fine for a sub amp or in a studio monitor, but not for real audio.

I emailed Dominic (Focal road man & a gifted acoustical engineer). I sent him a picture of one of my Blaupunkt door speakers - with whizzer cone & rotted surround. I told him that this was what one of their premier US Focal salesmen had in his car. Could he help? We went back & forth & finally agreed on the system above. He thought the deck would play the components well enough for a 20-year-old noisy convertible, but I insisted on trying one of their amps.

Lo & behold, a carton arrived from France just after Christmas. But it seemed awfully big.

Well, surprise, surprise, it seemed that Dominic had heard me when I mentioned that I would probably add a sub in the future. He figured I might as well get it over with. So, he added:



Subwoofer: Focal 21V2 - 8" Polyglass woofer - Two of them. Amazing build quality. It's a shame to hide them away in a sub box. I am certain that they can move some air.



Amplifier: Focal 1.800 - 1 x 400W rms 4 ohms (600W 2 ohms) A serious subwoofer amplifier - yes, it's Class D. Since I will run the two 4 ohm 21V2s parallel, the amp will be driving a 2 ohm load.

System Schematic

[imcarthur]

What's in the door, you may ask? Here you go. Remove the inner door panel. Make sure you write down the wiring code for the window switches before you disconnect them. Inside you'll find a vapor barrier of plastic that covers the innards. There's also a small plastic bucket that your POS Blaupunkt speaker screwed to. That's a rain shield. There's also a thick foam gasket to bridge the gap between the door panel & the door metal. Rip it all off & throw it all away.



When you get to the raw door, you will see a bunch of holes. That is Enemy #1 of good sound in a door. You have to fill them all. Your goal is to create a damped, sealed chamber for the mid/bass driver that is going in the door. Enemy # 2 is the door itself. It's made of metal & in will resonate & vibrate at various audible frequencies. That's where the dampening comes in. I used B-Tek's B-Quiet Ultimate dampening material. See their website. There are numerous choices: Dynamat, B-Quiet, Cascade Audio etc but I chose the Ultimate because it is decent stuff - spec & review-wise & it was shipped within Canada & didn't have to cross the border & the wallet-vacuuming that happens when this occurs.

Put the window up. Of course, you disconnected everything & you can't because it's a power window. So, move the door panel into place & re-connect the window wires. You wrote down the wire colors & position, didn't you? And if you've already ripped the other door apart, you have to connect that one too. Part of the circuit is in series.

With the window up, start applying your dampening material to the inner part of the outer door skin. Just reach in & put small pieces in place to the areas you can reach. That's only about 50% of the door but that will have to do.



Now, you're ready for the outside - well, actually inside . . . You need only one hole: where the door opener rod comes through in the middle of the door - just in the upper left-hand portion of the big oval in the lower portion of the door in the photo above. The only trouble spot, is the door lock rod that you can see disappearing into the top oval. Tape a plastic sheet (some of the old vapor barrier perhaps) over the rod so it can still move after you put sticky dampening over it. Also leave the thread & hole free on the door lock mechanism & the door handle bolt holes should be free of dampening so you can get the bolts on when you re-assemble the door. I also left all of the door panel screw holes accessible. Btw the foil backing makes an efficient vapor barrier, so you can skip replacing it.



When finished, cut out the speaker hole in preparation for the speaker spacer as per Peter Bull's great post on Pelican Parts see Mounting Door Speakers. You can see it in the photo below attached to the speaker hole. This accomplishes 2 things. It lets you have the initial speaker hole big enough for your 6.5" driver although the door opening should also fit. It also rigidly fills in the space that that lame foam gasket occupied, providing a flat screwable surface for proper driver fixing. Finished door pictured below.




Peter Bull's drawing of the speaker spacer. The Dremel is your friend for the red parts.


Dimensions of the speaker spacer. Peter suggested & I used 1/2" MDF from Home Depot

With the door finished, it's time to attack the door panel. For the mid-bass driver, remove the rain bucket & all screw fixings. That includes those embedded things that will rip the board apart, so remove cautiously. Remove the staples on the vinyl & mark out your required opening. Then Dremel it using one of the barrel sanders. It won't take long. For the tweeter, mark your diameter & Dremel the hole that was pre-punched in the door to the dimensions of your tweeter. The tweeter hole corresponds with a depression in the door, so depth should not be a problem. Then carefully cut back the vinyl & glue it down for both openings. The trim rings on the drivers allow a little leeway but not much.



Crossover placement now rears its head. I positioned the Focal x-over in the pocket under the door handle. That way, I can reach in to get at the 3 position switch for different frequency curves for the tweeter. The wires are routed back through the door panel & through the dampening into the door cavity for hookup.



Mount your tweeter & connect it to the crossover. Then use some dampening material to hold down the wires so they won't rattle once you get them back in the door.



The last job is to re-attach the door panel. Before mounting your mid/bass driver, it's probably a good idea to rewire the system. I used 14 gauge cable - big enough but also small enough. Pull new speaker wire through to the cabin using the existing wires as a pull. Just tape the new wire securely to the old, lubricate with Vaseline & yank away. Attach the speaker wires & fix the mid/bass driver in place. I also attached some plastic sheet to cover the top of the drivers as a rain shield before I screwed it down.

You're done the door components.



End of Part 1. Next up . . . mounting the amps.

Ian

[mthomas58]

Originally posted by imcarthur
First of all, a note to all who belong to the so-called "Church of Weight and Speed', whose goal is to reduce weight on their 911: Go for it guys. Strip it down, throw stuff out, have fun. Go build the ultimate 911 light-weight go-cart. It's not what I want.

While I'm at it, I might as well address those 911 owners who feel that the sound of the Porsche flat 6 is better than Mozart: I don't care. My car is a cruiser & I wanted a decent sound system. As for the flat 6? Yes, it's great. I love it, too. But on a freeway? At a constant 70 mph? Give me a break, it gets tiresome. Live with it if you want to, but I'd rather have Bob Marley along for those drives.

[/img]

Amen Brother......I could not have said it better myself!!!!!!!!!!!

Alpine CD/XP/iPod head unit (soon to be swapped out with Alpine DVD)
Alpine Blackbird Nav (trunk mounted dock)
7.5" LCD Screen mounted under dash for Nav,DVD and back-up camera
6.5" JL Audio component door speakers
Infinity 4 x 6 reference rear plate speakers
10" JL Audio sub/ custom box mounted in front trunk
5-channel Alpine Amp mounted under pass seat
Dynamat Extreme layered with 1/8" Dynamat foam throughout the cabin

I don't even hear the engine if I don't want to!!!!!!!!!!

Go for it!

[RWebb]

Great Write-up!

1. Do you know the volume of the sealed door?

2. What is the wt. of the smaller amps (Focal 2.75 - 2 x 75W rms 4 ohm new premium series of amplifiers from Focal)?

3. What no poly-kevlar?

4. Can you get Dominick to engineer some flat speakers for the rear package shelf, so we don't have to use Pioneers back there?

[imcarthur]

Originally posted by RWebb
1. Do you know the volume of the sealed door?

Good question. I estimated 35 litres. So about 3 times the volume that would be ideal. So the bass output will go low (in frequency terms) but it will lack control & definition. And that's exactly what it sounds like. I plan to cross to the subs around 80 Hz to start.

2. What is the wt. of the smaller amps (Focal 2.75 - 2 x 75W rms 4 ohm new premium series of amplifiers from Focal?

3.1 kg (6.83 lbs)

3. What no poly-kevlar?

No. That system uses the Tioxid tweeter which has a tendency to be a bit forward since the metal rings a bit at 2000 - 2500 Hz. My ear is VERY sensitive around there. I opted for the lesser system & its Al/Mg tweeter which is smoother in that area. Of course, I gave up some HF extension since the better tweeters have a better engine. And besides, it's a noisy Porsche.

4. Can you get Dominick to engineer some flat speakers for the rear package shelf, so we don't have to use Pioneers back there?

Haha. He'd tell me to piss off. I'll talk to Guy Bonneville at the next show. He's the head of 12V. Don't hold your breath though.

Ian

[imcarthur]

One step that I didn't mention above is speaker break-in.

All hifi components - especially loudspeakers - require break-in. A well-known & accepted premise in the audiophile community, it is usually ignored in a car system. Break-in is simple, just play music. The high frequencies mellow down & bass becomes faster & deeper. But since many don't do it, it often will take months before you have pounded on the requisite 100 hours + of play to actually hear what the system is capable of. So . . .



I hooked the speakers up in my cluttered office & used it as a radio/computer system for a couple of months. With cardboard boxes as enclosures, it certainly lacked a little punch, but I was surprised at the overall great sound. Hmm. Maybe I COULD get decent sound in my 911 - not a particularly kind environment.

And that's what I was after: decent sound. Not ghetto blasting bass. Not icily-etched highs. Just decent sound. But since I am in the business, the bar was set pretty high. Oh, ignore the rest of the clutter & the blatant logo display. I told the Focal car guys that I would write this & try to have a logo in EVERY picture! Haha.

Ian

[Porsche_monkey]

I wish you'd posted a month ago. That is what my stereo system should be.

[Paulporsche]

Great writeup, Ian. Can't wait to see the rest and hear it when we have you and Blanca over.

[johndglynn]

Great work and write up Ian, and superb schematics as always. I love Focal equipment.

[bourgeois911]

Awesome! Now, if only my 50 year old tin ears could appreciate the difference in going to this level of system. I will gladly add a few pounds of audio gear so I can listen to some old kick-ass rock and roll at several times the volume that is safe for my hearing.

[imcarthur]

With the door speakers installed, the next phase was electronics. I had 2 amplifiers to find a home for. The first thought is the traditional under the seat location. But since I have 2 amps, they wouldn't fit. The other big drawback to this location, is cabling. You have to route all of the power cables, speaker cables, remote trigger & any control cables under the carpet to the amp's position. Not a real problem except for the power cable. A power amp produces voltage & current to drive the voice coils in your drivers. The better the amp, the more it produces. And the more it needs to feed its own power supply. The longer the cables to the amp, the larger they have to be. It's roughly 3 meters from battery positive to an under-the-seat location. For the Focal 1.800 that means a 2 AWG power cable. Now that's a pretty hefty cable to try to route through a car. Even the smaller Focal 2.75 needed 5 AWG for that length. For 1 meter, I could use 4 AWG & 8 AWG respectively. These sizes are easy to find & it also meant I didn't have to pull them through the bulkhead. So, close to the battery was the ticket.

In an effort to preserve the deep part of the trunk, I fixated on the spare tire area. I thought about ditching the spare completely, but I knew that on my very next drive, Murphy's law would prevail & I would need it. So it stayed. And I decided that a position skewed away from the battery was ideal to allow access.

I used a 1/2" piece of MDF & mounted the amps to it. I then got a 3" (I believe) carriage bolt & some washers & nuts. The bolt is fixed to one of the spare tire lug bolt holes with the thread sticking up. I drilled a matching hole in the MDF & positioned it above the protruding bolt. That way I can undo the bolt & lift the amp board to access the spare on the road. I just have to always have a 5/8" wrench in my tool kit. I over cut the wire length slightly so it's not too tight to prevent the amp board from lifting.




Of course, I painted the board a metallic rattle can grey & the bolts were all given a coat of black to make it all look purty.

Then it was time to do the cabling. I visited a dealer who's a friend of . . . it doesn't matter. I bought some 4 AWG cable for the sub amp hot & ground. 8 AWG for the component amp. I also got some big butt ring terminals for the battery connection & some fuse holders that accept big fuses & big cables - 30A for the 2.75 & 70A for the 1.800. The 1.800 is technically a 90A load but they don't seem to make glass fuses that size to fit the fuse holders, so I'll have to see if it works long term. The only other option is a separate fuse block & I don't want to go that route if I can avoid it. The amps should be fused within 40 cm of the battery.

First up was the ground. I located it on the metal reinforcement channel on the passenger side. It was easy to drill since it's not thick & you can easily access it & you don't have to drill a hole in the tub. Hole drilled, a quick Dremel got it down to bare metal. All wires were tinned & then crimped & soldered in ring terminals. And it's not easy soldering a 4 AWG cable but persevere to make a solid vibration-proof connection. A lag bolt with washers finished it.



With the battery disconnected, the rest of the power connections were straight forward. Ring terminals at the battery connection, fuse holders wired about 8" away & soldered bare wire into the amp. Did I mention what a pain it is to solder 4 AWG cable?



Now it was time to get the cables through the bulkhead. After some investigation, I concluded that the painless route was through the opening for the heater hose on the passenger side. The gasket is pliable & everything went through easily. Everything consisted of: right & left 14 AWG speaker cable pairs for the door components, another 2 for the subs (one pair per driver), a RCA line level interconnect with trigger wire to the head unit & the remote sub control wire. I only needed one pair of line level cables & one trigger wire because you can daisy chain the 2 amps with these.

Pictured below is the amps installed & wired but I haven't dressed the cables yet (or connected the sub amp speaker wires) which I'll do at the final stage.



Mounting the head unit proved to be a 20 minute job. I have a Blaupunkt Orlando. Just for fun, I tried it driving the door components without a power amp before I mounted the amps. It sounded pretty lame. Using a cut up coat hanger as keys, the Blau was removed. There were 3 connectors plugged in the back plus the attenna lead. One connector was speaker leads, one was the feed for an accessory remote CD changer & the last was the power connections. I soldered the new wires from my Dual unit's harness to the battery, ignition & trigger wires & plugged in the amp line level lead & the antenna cable. The antenna cable also has a little power lead to power its amplifier.

I pulled out the Blau's adaptor housing & fitted the Dual's. They looked almost identical. The Dual slid in without pain or fuss. Easy, easy install.



At this point, I have sound. The subs are not installed, so I'm running the main amp full range into just the door components. And it sounds very good. The Dual ain't half bad for a cheap deck. It's not splashy at all but the bass is a bit muddy as I suspected it would be but surprisingly deep. Vocalists are clear without shouting. I guess the door build is doing its job. I could probably live with it as is but now I want more. The subs should do the trick when I get them installed.

I will post more later in the week as I progress . . .

Ian

[Porsche_monkey]

Where did you buy that stuff?

[Rusty Heap]

sub'd and prop's for your great work!

[rusnak]

where will the sub go? Did I miss that part? I like the remote sub controller. I used an in-line controller between my external crossover and the sub amp.

I have three amps in mine. the rear speaker shelf is a great location since the speakers are near ear level. You only need to have a spacer made, and you can install 7" rounds with no problems. I also have external fuses for each amp and a really trick Monster Cable battery clamp, a necessity I'm afraid.

[RWebb]

Thanks Ian. You've made a lot of xlnt points that other threads have neglected, including the need to 'break in' good speakers.

Focal might also think about making a small enclosure to get around the large size when using the doors as enclosures. That would allow the door mount drivers to do their best and eliminate the wooliness in the sound from a too-large enclosure. I know some have have tried to rig flex-pipes for this, but they are... flexible, so not the best.

Keep posting...

[herr_oberst]

Can I have the plastic rain shields from your doors before you throw them out?

Thanks,

mo

[imcarthur]

PBH – I got it direct from Focal in France. And unfortunately no, it’s not a route I can offer to others. The Dual I bought online - well, my kids did for me for Xmas.

Rusnak – Not installed yet. That’s this week’s project.

Randy – As I’m sure you know, it’s a good idea but not practical. The first problem, is how do you get something rigid & inflexible into the door? What volume? As a full bass box? Or to stop at 80 Hz for crossing to sub? What driver? And on & on . . . I thought about partitioning that lower corner of the door internally but decided it was pretty impractical. If I was not adding subs I might be more concerned. If the mid-bass still sounds indistinct with the subs added, I might have to come up with a Plan B.

I’ll keep posting my results.

Mo – Sure. Do you want the foam rings too? PM your address & I can stuff ‘em in a box & mail it.

Ian

[RWebb]

I was thinking to stop at 80 Hz for crossing to the sub - and for a Focal driver of course.

Someone 'might' be able to make something that would have a decent run - 1,000s and not have to put too much into it. Suppose you fabbed it out of PVC, then went to a more moldable plastic, and pushed it out into a sort of trochoid triangle at the bottom of the door, with a flat or indented top to clear the window when down.

I don't plan to run a sub (or at least not a very large one) in my Church of Light (Wt.)* car, so I probably have more concerns than you.


BTW, the "Church of Weight and Speed' is merely a mis-quote of the one true church (which I, ahem, founded - years before Pelican, on the Email version of Rennlist).

As the Pope has patiently explained, it therefore cannot be a true church and all its adherents will burn in hell.

[rusnak]

The McLaren F1 used special titanium speakers and subwoofer, all for light weight and great sound.

I was able to re-use the speaker wells that were in my door. I don't know if the PO installed them or if they're factory, but they work. Thus, no need to seal up the door openings.

I hear a lot of people say that the 911 is not a great sound environment, but I think it's alright. The inner door panels are made of metal, which is unheard of today. All cars have cardboard inner door panels. Metal is far better to mount the speaker drivers on. You can get the little directional cones of your speaker separates aimed right at your ear from the other side of the car. And there are no rattles or squeaks in a 911.

Bad sound environment? Try a 914. Or any pickup truck. Or a 911 cabriolet. An El Camino. Boxster. You can make the 911 a great sound environment with a little work. I just think most 911s are way under designed in the way of speakers, speaker sizes, and power delivery.

[Mysterytrain]

Ian, Nice work! Its great to see you branching out from heating circuits . I'm hoping to dig into my doors this fall and attempt to install some 6.5" focal coax speakers behind the original round SC grilles. I'm not sure the grilles will work.