E30 Audio Overhaul - My Project Details

[318Joe]

A little closer...

Thanks for the writeup. Could have used it when I tackled my tweeter replacement.

I don't know if it changed over the years, or if it was the luck of the draw, but only one of my tweeter pods had that lip. The other had that lip attached to the tweeter, and had no retaining lip on the pod shell (top):

[bmwman91]

I emailed Audio Control asking them about running the CD43 outputs directly to the 6XS. The inputs are unbalanced, so the device only uses the "+" input, and the "-" input runs to ground. This means that the connection to the CD43 will ONLY use one of the outputs per channel, and the 6XS "-" input will be grounded to the chassis. If you run the "-" output from the CD43 to the 6XS, it would basically short to ground.

They also mentioned that I could use their level converter to take the CD43 inputs (+ & -) & run that to the 6XS, but I don't really see the point if the level converter is just turning the CD43 outputs into unbalanced ones, since the 6XS could just use one output directly. The 6XS can handle inputs of up to 15V before clipping occurs on the input stage, so I do not have any qualms about running the CD43 to it directly.

One advantage to using the level converter is that running the differential signals to the trunk would improve noise immunity. Then I would only be running an unbalanced signal a few inches from the LCO to the 6XS. I can always add that later on.

[bmwman91]

No, he said use the chassis ground as the shield on the RCAs...not short an output to ground.

Aaah haha, yeah that sounds about right.

I have been making more preparations for the build. I received my tweeter pods & have been "cleaning" them in preparation for the tweeters I want to install.

To get the stock drivers out, use a small flat-blade screwdriver to pry the metal body out. You can crank on the plastic ring around it & mess it up because it is coming out next.


Getting the ring out is a little more work. Needle-nose pliers are a good tool for the job. Grab the ring from behind & lever inward to break the glue holding it into the pod. I found that getting it nice and hot with a blow drier helped soften the (ancient) glue. Just work carefully, and once the glue cracks in one or two places you can probably yank it out.


I used some small cutters & a Dremel with a flexible sanding disk to remove the inner molded ring. I wanted the inside surface nice and flush for the installation of the tweeter.


A little closer...


Don't judge me...engineering is a disease. Sometimes I catch myself folding a towel before tossing it into the hamper. Anyway, I want this planned out 100% before buying drivers.






The important dimensions are added. That inner lip is best cut off. If you don't want to cut it, it sticks up 1.4mm past the inner surface, and is 1mm thick.


Just in case you were wondering how much room you get (depth), here are the important domensions on the tweeter. I am not sure how much more space you have beyond this, and I have no intention of modeling the whole door!


So there I am for now. I just need to figure out if there is any way to get a 75mm deep woofer into the front cutouts. I measured 69-73mm from the mounting surface. Spacers are not really an option since I want minimal interference with the covers. Does anyone know if there is anything behind the metal? I can easily "engineer" some additional depth with a 2x2 & a big rubber mallet, as long as I am not hitting the fender or something.

[StereoInstaller1]

No, he said use the chassis ground as the shield on the RCAs...not short an output to ground.

[bmwman91]

subscribed.. Take lots of pics of this install!!!

I always thought with the cd43 that you only needed the + speaker wire and you were supposed to ground out the - on the RCA to the CD43s ground???

You DEFINITELY don't want to run any of the outputs to the ground. It has a DC offset of ~1/2 the battery voltage, plus the audio signal. The output driver would blow faster than a hooke....nevermind. Just don't do it lol.

[Spaz]

The speaker wiring from the amp to the speakers is not any kind of shared ground, and depending on the car there is sometimes only the fader wiring that is shared ground. Dig into a couple different cars' wiring diagrams, it is just bizarre.

Ah sounds pro :D

[StereoInstaller1]

Setup looks amazing bmwman91

But i have a question for luke.



Let me get this straight...
So when you're installing a new deck to an e30 you reuse the old speaker wiring but in a proper non shared ground setup?

Hmm, i might have to try this myself.

-Cam

The speaker wiring from the amp to the speakers is not any kind of shared ground, and depending on the car there is sometimes only the fader wiring that is shared ground. Dig into a couple different cars' wiring diagrams, it is just bizarre.

subscribed.. Take lots of pics of this install!!!

I always thought with the cd43 that you only needed the + speaker wire and you were supposed to ground out the - on the RCA to the CD43s ground???

Will not matter on the input of the 6XS. Audiocontrol is smarter than that.

I would likely do the chassis ground for shield, but that has just become my norm now.

[BeirBrennerE30]

subscribed.. Take lots of pics of this install!!!

I always thought with the cd43 that you only needed the + speaker wire and you were supposed to ground out the - on the RCA to the CD43s ground???

[quickervicar]

This is going to be good :)

[Spaz]

Setup looks amazing bmwman91

But i have a question for luke.

2. Speaker wire: the stock BMW wire will sound better, fit better, last longer and just in general kick the shit out of whatever 14 ga you are gonna find.

Let me tell you, I have pulled many miles of 5 year old "monster" or whatever (even supposedly high end stuff, OFC, linear crystal, whatever) out of cars. I have pulled crap I put in myself 10 years before...ALWAYS nasty looking. High dollar wire is a complete sham IMO, except ONE brand: Kimber. I have pulled 20 year old Kimber and it still looked great. I have never heard a wire sound SO much better, and nothing rejects noise better, nothing. I have done 5 or 6 cars with it over the years. When mine gets redone this summer, I am gonna run 1 run of 8TC up each side, then split the conductors before the drivers, using 6 conductors for midrange and 2 conductors for tweets, since my system is active, too.

Let me get this straight...
So when you're installing a new deck to an e30 you reuse the old speaker wiring but in a proper non shared ground setup?

Hmm, i might have to try this myself.

-Cam

[bmwman91]

Hey, no shame in that! Paper still gets the job done...and it is faster for brainstorming, for sure. Trust me, I went through a few sheets before committing anything to Inkscape.

Oh, and my CD43 is waiting for me at the post office (wasn't home to sign for it today). Yay.

[StereoInstaller1]

gotta be better than this, right?

[bmwman91]

1. I believe the CD43 to have enormous pre-amps, I don't think it has any actual power IC, but I could be wrong. I would love to see my theory proven one way or another...you have brains, I have experience, between us I think there is proof somewhere.

I actually don't wanna say anything else on this install: you clearly have things VERY well in hand, and I don't know that I can be of any real help!

i will DL and install inkscape, seems badass. If I can do half as nice as yours, I will be thrilled. Do you think it will let me make subwoofer box drawings too?

I can check the idle current pretty easily with a DMM. There is equipment at my work that I can use to measure peak/RMS current in operation, but that is a lot of work. I might be able to rig something simpler up to get an approximation.

Inkscape can be a pain in the ass until you get comfy with it. It took me like 5 minutes just to find the icon that turns on the stroke settings sidebar! You will be just fine once you try some beginner tutorials. Turning on the grid & snaps is highly recommended for things like this.

You definitely CAN use it for box drawings, although making changes could be time consuming. Personally, if I needed something fast & free for doing enclosures, I would look at using Google SketchUp. You cannot make dimensioned 2D drawings with it, but it is super simple to model with and you can add dimensions onto the model. It is nifty for making 3D drawings, for sure. Of all the CAD programs I know, it is by far the easiest to use, albeit limited in capabilities.

[StereoInstaller1]

1. I believe the CD43 to have enormous pre-amps, I don't think it has any actual power IC, but I could be wrong. I would love to see my theory proven one way or another...you have brains, I have experience, between us I think there is proof somewhere.

I actually don't wanna say anything else on this install: you clearly have things VERY well in hand, and I don't know that I can be of any real help!

i will DL and install inkscape, seems badass. If I can do half as nice as yours, I will be thrilled. Do you think it will let me make subwoofer box drawings too?

[dinanm3atl]

I will follow along. Looks like quite the setup! Your ears will enjoy!