Tweeter Install Wiring

E28 technical advice asked and given! Troubleshooting, modifications and more.
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teh
Posts: 21
Joined: Apr 16, 2024 1:00 PM
Location: Germany

Tweeter Install Wiring

Post by teh »

Hi everyone,

I am in the process of upgrading the audio in my e28. I am doing a complete rewire since my car originally did not have the pro audio option. It only had 4x6 speakers in the footwell and nothing else.

I have done everything beside the install of the tweeters and I am wondering how to go about the wiring. I want to install them in the original location so I need to run cables into the door. There is this rubber sleeve/tube going from the car into the door but I am wondering how on earth I can get my cables in and through there. Any ideas? Other solutions?

thanks!
vinceg101
Posts: 4878
Joined: Jun 20, 2007 2:40 AM
Location: Los Angeles, CA

Re: Tweeter Install Wiring

Post by vinceg101 »

So, so, so many questions:
1. First off: No there is no other way to route wires from the cabin to the door cap area other than through that rubber boot/sleeve. That sleeve does detach from both sides so you will have do that and then fish your new wires through it. It will be tedious but if the wires are thin enough (e.g. 16 or 18ga.) then you can use some sort of flexible metal wire (e.g. welding wire, etc.) to push the wire through. You will then have to remove the interior door panel, upper door panel sill cap (right below the window),the interior cover cap right behind the exterior side mirror (since this is where the Premium Tweeter goes), and the lower bass speaker and carpet panel in the kick area (you need to find your door wiring harness running up from the floor so you can follow it up to the rubber boot/sleeve).

2. You didn't mention if you were installing the exact BMW Premium Sound System or if this is all aftermarket equipment. If the former, then I can't remember how they wired the upper tweeter (either direct from the amp or as a jump wire from the lower footwell bass speaker). You need to check the ETM to see the wiring diagram. If the latter, then you wire from your new amp or new head unit (provided it has 4 channel out via speaker wire) to a crossover and then from the crossover separately to the lower bass and the upper tweeter (most popular location for crossovers is under the rear seat).

[NOTE: The OEM BMW audio wiring is different from all other aftermarket wiring systems and hence their amps and head units have different grounding methods. Consult the ETM. So research if you plan on mixing and matching BMW with aftermarket components.]

If your existing rubber boot/sleeve is broken and/or disintegrating, Ivo Christov sells new ones since BMW stopped making these a long time ago. You will have to take apart your door wiring connectors (central locks, side view mirror controls, and door window motor controls) to fish the wire harness back through the new boot, but you can run your speaker wires at the same time.
Blue Shadow
Posts: 10281
Joined: Feb 12, 2006 12:00 PM
Location: SE PA

Re: Tweeter Install Wiring

Post by Blue Shadow »

When I installed the door tweeters in my car I just left a chunk of wire available to jump the gap from the dash to the tweeter. It was this way for a while. Took me 4 years to run that wire through the then still flexible wire cover between the door and the chassis. Of this 4 years, 5 hours were used to run the first one and 2 hours we needed to run the second one.

Today, I don't know if this could be done without damaging the that rubber cover as it is dried out and ready to crack/break. Glad to see Ivo has this cover part available.

The Premium Sound tweeter is connected to the kick panel woofer as that has the crossover built on it.
vinceg101
Posts: 4878
Joined: Jun 20, 2007 2:40 AM
Location: Los Angeles, CA

Re: Tweeter Install Wiring

Post by vinceg101 »

Blue Shadow wrote: Dec 02, 2024 11:47 AM The Premium Sound tweeter is connected to the kick panel woofer as that has the crossover built on it.
This is what I couldn't remember, it's similar for the rear parcel shelf speakers being self-contained.
The lower 4x6's are different between the standard and Premium Sound systems due to this crossover for the fronts. The standard system uses the same 4x6 for both front and rear and carries a different part number.

So to the OP: Verify you have Premium Sound front lowers in order to get your upper tweeters to work.
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