Understanding E30 speaker and amp wiring

[bradnic]

just received my power amp connector from RyanBelton . It is very well made and documented. Highly recommended.

[bradnic]

...a class D 4 channel amp could potentially fit in the original amp housing. It’s a lot of work though. You can accomplish the same thing with an amp bypass and wiring in a small commercial class d amp. It does require cutting the harness though. The key issue is sourcing the connector on the amp housing. I haven’t been able to find it yet.

If you can't find the stock amp connector anywhere, you might consider replicating it in CAD and 3D printing it.

There are lots of places to get high quality 3D prints now a days. Stratasys, Xometry, ProtoLabs to name a few.

RyanBelton is offering a 3d printed connector that you can use to make an aftermarket amp harness with.

[bradnic]

ave30rudy did you figure it out? info is in the schematics above. if you ended up with one solid yellow and one solid blue wire unconnected, then you have not connected the head unit to the speakers. From your description it sounds like the two wires are at the trunk amp connector.

[ave30rudy]

so I did all the new head unit wiring, all the speaker wires connected to the new speaker wires, and power etc. Then I have one yellow wire and one blue wire, both coming from the power bundle, not the speaker bundle that have no where to connect to. I went ahead and did the whole amp bypass wiring as well. However I still have no sound. My assumption is that my problem is coming from those two wires in the dash. But my question is where do I connect those?

[CW325]

On an early model 2 channel radio only car would I need a “floating ground adapter” or could I just share the front/rear negatives for each side?

Update: after doing some more research I ran new negatives for the 2 front speakers and left the existing negatives as dedicated rear negatives.

[CW325]

On an early model 2 channel radio only car would I need a “floating ground adapter” or could I just share the front/rear negatives for each side?

[bradnic]

quasi mofo sounds like you are going aftermarket. Just head over to the stickied @stereoinstaller wiring thread in the same audio forum

that harness adapter is the rear speakers only on cars with premium sound and 4 channel radios.

you will also have a blue and a yellow wire with a speaker connector on it. Those are the positive leads for the front speakers

Drop me a PM and I’ll be happy to buy the wiring bits you remove from you

[quasi mofo]

Here is a standalone picture of the 2 to 4 channel adapter, part number 61101388934

Note that there are no ground wires in that harness.

Can this adapter be deleted and the in dash speaker wires run directly to the head unit? The PO of my car just the far end "LH" and "RH" labeled cables and used butt connectors to run them to the head unit. The green/black and purple/black negative left and right rear speaker wires connected to this second harness. The positive green and purple wires aren't connected to anything. Currently still only have sound to the right tweeter, left tweeter and left front and rear speakers.

I still want to use the stock wiring so I don't have to pull apart the interior again, but at this point maybe I should just delete everything and run my own cables.

[bradnic]

I updated the original post with more info, including an example of a two channel radio amp bypass. the 2 channel radio BMW sound system setup has fewer wires going to the power amp connector than the 4 channel setup.

[bradnic]

winterse30 that's a wide open question, very hard to answer. I assume this is a factory radio setup. if you can pull your radio to access the speaker wiring, try swapping the left and right speaker wires. If the working speakers change to the other side then the problem is your radio. if the same speakers still don't work then it's not the radio. You just need to keep isolating stuff until you figure out where the problem is. good luck

[winterse30]

Hey this maybe off topic. I’m new to R3V. Just wondering if I can get some help. My front and rear speaker aren’t working on the drivers side of my e30 sedan. What could the possible issues be? I’m not familiar with wiring etc.

[JeffWiley]

Hi...if you are wiring a car that did not have a factory amp, you'll have 4 twisted pairs that run to or near the head unit location. Sometimes you'll have to cut back the harness wrap a bit to find them. Each pair is a +/- set with the signal wire color as described above and the brown stripe wire the return ground. Wire the speakers as specified by the head unit manufacturer.

pcb assembly

[bradnic]

I couldn’t disagree more with you George, but to each his own

[george graves]

I’m actually working on an amp bypass kit that uses the existing amp housing.

Awesome! Let's see some work!

@dimrun2002 I respect your view, but generally disagree.
- The E30 headunits were made by Alpine and Pioneer, not BMW.
- The BMW Sound System speaker drivers are very high quality actually.

Yhe stock BMW speakers are crap. They are fantastic if you consider 1990's factory car speakers as a baseline. But even driven with a nice amp, they are muddy, with a ton of resonance that make it sound like there is a midget ringing a bell, all the while banging on a Amazon cardboard box in your e30.

Luke Fisher tried to get us all to go down that rabbit hole.

[bradnic]

Any luck with this? I am thinking I can use the radio output lines to feed signal to a digital sound processor. It would be great to just plug in a harness instead of the factory amp so, the factory harness is saved. I am not sure what kid of wattage is coming out of the OEM head unit. Would I wire the signal to speaker level inputs or adapt them to an RCA input?

There are line level/output converters out there if you want to use external amps and line level inputs..
Here’s a good Crutchfield article about them

I did get an Infinity Basslink DC powered sub (10" driver+ 10" passive radiator) setup working with the existing premium amp. but it's too big for my vert :-)
Sounds darn good though.

Still looking for the connector. I will have two plug-n-play two harness adapter kits when I'm finished:

-- one to keep the OEM blaupunkt premium amp and add a powered sub.
-- one to replace the OEM premium amp with an external 5 channel amp and sub.

I use to stick a HUGE PPI 4800.2 on trunk wall between tail lights.Right next to the battery and took up very little trunk space flat against the rear valance panel.

That's a cool mount location but you do need to extend wiring back around further. Most folks probably mount behind their rear seat.

Looks like the PPI 4800.2 is a 4 channel amp. Infinity sells a Reference 4555 5 channel that's smaller, $100 less and supports 500W to the sub. you don't really need big power for the other channels - 45W should be enough for most folks.

Click on pic for Crutchfield listing


Stay tuned..