Understanding E30 speaker and amp wiring

[bradnic]

so it turns out that in Europe, some late model E30s including the tourings used the 17 pin connector found in early E36 cars. That single connector combines all the radio wiring including 4 radio output channels, power and ground. Tourings all came with 17 pin harnesses, part numbers 61-12-1-394-213 (sound system) and 61-12-1-394-212 (radio only). There were also part numbers for coupe/sedan/M3, 61-12-1-394-211 (sound system) and 61-12-1-394-210 (radio only). Convertibles had 17 pin harnesses as well, 61-12-1-394-215 (sound system) and 61-12-1-394-214 (radio only).



There are some very cool OEM BMW radios with this connector. They won't sit flush on your HVAC panel without modification, but you can get a 3d printed bracket for that thanks to D.Martijn, thread here. I will have these on my website shortly for $15 (basically the cost of printing with a small margin). I will also have an HVAC switch blank adapter for the Cantaloupe Radio microphone.

You can also get 2 or 4 channel harness adapters from BMW like 65-12-8-350-192 to add the connector to your car if needed, or make it yourself once you source the right connectors (square connector bot hard, rest not easy, especially the proprietary fader connector). There were multiple versions of these adapters for 2 or 4 channel wiring, radio only or sound system.


Here's an example that is THE OPPOSITE of what you would need. One of my customers with 17 pin Touring wiring put this together with my help so he could run a CM5908 and Cantaloupe Radio BT. BMW sold a similar adapter as 65-12-8-350-189:

[bradnic]

For those of you considering speaker or amplifier upgrades, harness adapters can be used to protect the factory wiring. Speaker upgrade options vary based on the body type, but in general:

1. speaker sensitivity is important to balance sound between front and rear. without that balance you'll need to move the fader off of center
2. component speakers like the Focal 130AS are great replacement for the kick panel speakers and door tweeters. I wouldn't personally modify the tweeter pods, instead pick up another set or get some 3d printed versions
3. for convertibles, the top priority speaker wise is to replace the standard rears with coaxials. Speakers like the Focal ACX130 are a great choice here.
4. for those with premium wiring, you can add a no-cut amp bypass harness now which will let you keep or swap out the factory trunk amp, add a monoblock amp and passive sub, a 5 channel amp or a 4 channel amp and powered sub. cars with front batteries will need to wire power to the trunk to run a sub.

Here's an example of a front speaker upgrade using the Focal 130AS component speakers. There are harness adapters for the new crossovers and door tweeters, as well as a kick panel spacer to keep the new speaker surround from hitting the trim.

[bradnic]

Just finished repairing and restoring a 719 sound system audio harness for a Cecotto M3 build. BMW Classic assisted with engineering details from the original drawings.

[bradnic]

been having fun assisting customers with radio installs over the last few months:
-- premium audio harness restoration on a Cecotto E30 M3 (LHD euro spec) with a Becker Bavaria Electronic radio
-- premium audio and subwoofer retrofit on an 87 325i coupe
-- convertible wiring restoration on an Mtech 770 convertible.
-- 4 channel 5908 retrofit on a late model touring.

The info on this thread has helped a lot of folks, but inevitably the things I didn't get to came up in every one of these projects. BMW Classic has been a great help too, clarifying things for us whenever we had a VERY specific question to ask. So I thought I'd share some of these lessons here. Will update the original posts on this thread as well

SOUND SYSTEM ON COUPE/SEDAN VS CONVERTIBLE VS TOURING..

If you really go nuts on realoem you will note that the audio wiring on a coupe or M3 is different from a convertible - or a touring. This is mostly due to speaker placement, but also wiring changes were introduced in Europe during E30 production that were not present elsewhere. Here's what we found

• There's a 61-12-1-381-719 harness part number used sound system on coupe, sedan or M3.
• There's a different 61-12-1-381-718 harness part number used for sound system on convertible
• Convertibles add a *really* bizarre speaker harness that routes from the driver side kick panel to the other 3 corners of the car. Also weird is that this harness uses the "radio only" wiring color scheme that connects to a 6 pin connector near the driver front kick panel speaker with the rear amp out speaker wires. It seems that BMW intended to connect to all four speakers with this added harness at one point, but decided to use only the rear speakers for production. The most likely explanation for this was a switch to individual speaker grounds (i.e., there were only 2 grounds available for all 4 speakers on a 6 pin connector)
• The late model E30 tourings used the 17 pin connector found in early E36 cars that basically combines all the wiring for the fader connector with the other power and ground wiring that went to the radio.
• The wiring in both the 718 and 719 sound system harnesses changed to a twisted pair setup at some point, but the part number was not changed. BMW Classic could not confirm the exact date of the production design change, but it most likely was most likely near the time 4 channel radios were being introduced.

[bradnic]

That’s a 5908 radio, and the wiring to the radio appears to be intact and correct. It’s a 4 channel common ground system. You can see the ground wires attached to the back of the radio heat sink. The other speaker wires attached to the radio are all positive.

check the 4 channel bmw sound system schematic in the first post so you can see how the radio grounds and speaker grounds are supposed to be wired

you also mentioned one of your speaker ground wires has power. A premium system has a different set of speaker wires than the wires coming from the radio. Again, check the first post for details there including the speaker wire colors. Not sure if any of the trunk amps you are testing with are actually known to work, or have been rebuilt. They are 32+ years old now - If they have not been rebuilt there’s a very high probability they are bad.

[cajon]

bradnic Thanks for the questions! I have an early '91 325i convertible (with diving boards). Unsure which radio I have, but the car came with no in-dash fader -- I've attached pictures of the radio, wiring, and some little diagnostics. I doubt any of the three amps were refurbished, but I opened one of them up and it looked mint -- no bulging resistors, bad wiring, or anything that I could see. Wiring throughout seems unmodified to me, but there are some areas where someone has put electrical tape on it (no breakages beneath, but just indicated someone poked around). Here's some pics:
Amp harness wiring (I pulled back the green protector to test for ground. It's grounded here from the amp (brown wire)):

Stereo wiring with two unused connections:

Face of stereo itself:

Ground wire discrepancy noted in my first post -- notice that this is one of the four speaker wires in the amp harness that is connected to the brown amp ground wire:


Let me know if there's anything else I'm missing, thanks so much!

[bradnic]

cajon what car do you have? What radio? You say you swapped amps out. Have any of them been refurbished? Is your stock audio wiring unmodified?

Some pics would help

[cajon]

Hey all! Sorry to revive such an old thread, but I'm looking for some insight into a rather strange issue I've run into in diagnosing my '91 vert speaker system (symptoms: very faint sound/"unamplified sound" at max volume, amp does not seem to be the issue after having tried 3 different amps). Normal vitals seem alright -- amp seems healthy and receives power, head unit powers on with no issues, etc. but after having pulled the left rear door card speaker, I've discovered that the speaker's ground wire (yellow with brown stripe) is somehow receiving power. I checked around the amp harness area and confirmed that the connection of the four speaker ground wires to the brown/black ground wire from the amp is healthy and properly grounded (the four speaker wires and one amp ground wire are all crimped together, and the test light doesn't indicate any power is received in this area).

So basically, as far as I can tell, the speaker ground wires are getting grounded where they should be by the amp, and seem to somehow be receiving power by the time they get to the speakers. Does this mean that I likely have a break somewhere in my wiring? I'm super new to speaker wiring and all of this, so I'm really dreading having to search for that if it comes to that -- I just wanted to ask here before proceeding any further to see if any of you had any ideas. Thanks again!

[bradnic]

For those that may not be aware, jaysterling from Cantaloupe Radio have released a new series of Bluetooth products. In addition to the BA31 bluetooth board, the 5908 will have additional options including an LCD replacement called Display+, and quite exciting, a replacement for the 5908's internal amplifier called Amp+. It's a big deal because of the clean, high power as well as line level outputs, sub-out and EQ support. If you have interest in Amp+, I wanted to layout the OEM+ audio upgrade options now including Amp+.

tldr:
1) upgrade to the factory BMW SOUND SYSTEM if you don't have it, or keep standard wiring, add a 5908 with Amp+ and just upgrade your speakers
2) consider adding a trunk sub as well
3) if you choose not to use Amp+ with a 5908, or are keeping a 5907, add 4 or 5 channel amplification to replace the factory trunk amp if you have it.

OPTION 1A (5907 or 5908) - UPGRADE TO BMW SOUND SYSTEM IF YOU DON'T ALREADY HAVE IT

This involves retrofitting the premium sound harness to your car, as well as the premium speakers which include crossovers and tweeters. This gives you the baseline premium audio configuration, 5907 or 5908 with a Blaupunkt trunk amp, higher quality speakers and tweeters.

Most all verts already came with BMW SOUND SYSTEM in USDM (not sure about the late model 3i8ic). Even with premium audio, the stock rear speakers on convertibles don't have tweeters. So consider adding coaxial speakers to the rear quarters.

OPTION 1B (5908) - IF YOU HAVE STANDARD AUDIO AND ABSOLUTELY PLAN TO BUY AMP+ YOU CAN LEAVE WIRING STOCK AND UPGRADE SPEAKERS

If you have the standard audio system and will be running a 5908 and Amp+ you have the option of leaving your car’s stereo wiring unmodified. The one exception - if you have 2 channel standard wiring and your car came with the round pin fader, you will need a BMW 2-to-4 wire adapter to run the 5908. You can also add a trunk sub since you have Amp+ - see OPTION 5. What you won't be able to do though is run aftermarket trunk amps as well (OPTION 6), because the wiring from the trunk to the front speakers is missing. So if your want a 5908 and OPTION 6, go with 1A.


OPTIONS BEYOND STEP 1 USING AN AfTERMARKET TRUNK AMP (5907 or 5908)
Nothing new here, but they are the baseline option for adding more power to E30 audio systems.
Amplifier tech has improved dramatically in recent years though, and you're still using speaker level inputs from a 30+ year old radio, which has much higher "THD" total harmonic distortion at power than a modern amplifier. Folks have also added "line converters" to their speaker level input wiring which helps a bit, but you can't get rid of the THD generated by the radio amp.

OPTION 2 (5907 or 5908) AFTERMARKET TRUNK AMP
start with the stock premium setup in option 1. Do a trunk amp bypass and use the speaker level outputs from your radio as inputs to an aftermarket 4 channel trunk amp

OPTION 3 (5907 or 5908) 5 CHANNEL AMPLIFICATION AND TRUNK SUB
upgrades option 2 with 5 channels of amplification and a trunk subwoofer. You are still using speaker level inputs though, or speaker level radio outputs with line converters to get you a line level input to the amp. There are several ways to do this
- use a 5 channel trunk amp and a passive sub
- use a 4 channel amp with a powered sub
- use a 4 channel amp and mono block sub amp with a passive sub

OPTIONS BEYOND STEP 1 USING AMP+ (5908 only)
Amp+ is a game changer, no other way to describe it. AVAILABLE LATE 2023
- a fully digital signal path for your BT and AUX input sources to a new high power amp built into the radio itself
- tuner outputs go through the digital signal path to the amp as well (but the tuners themselves are still analog)
- ridiculously low THD - think 100x less distortion at power vs the stock trunk amp and radio amp. SUPER CLEAN HIGH POWER AUDIO.
- pre-out and sub-out
- custom EQ controlled directly from the radio itself, when paired with Display+

There are multiple ways to deploy it, listed below. Again, the higher the option number, the better the OEM+ audio capability.

OPTION 4 (5908 only) ADD AMP+ AND IF YOU HAVE BMW SOUND SYSTEM DO A TRUNK AMP BYPASS
Standard sound system: Retrofit Amp+ to a BA31 equipped 5908. Enjoy
BMW SOUND SYSTEM: Retrofit Amp+ to a BA31 equipped 5908. Pull your OEM trunk amp and perform a trunk amp bypass. Enjoy

OPTION 5 (5908 only) ADD TRUNK AMP AND SUB, USE AMP+ SUB-OUT
Start with option 4. add a line level sub-out from Amp+ to either a mono block amp and passive trunk sub, or a powered sub

OPTION 6 (5908 only) AMP+ WITH AFTERMARKET AMPS AND SUB
Start with option 4. Add preouts to 5 channels of aftermarket amps
- 4 channel aftermarket trunk amp, powered sub
- or 4 channel aftermarket trunk amp, sub amp with passive sub
- or 5 channel trunk amp with passive sub

The difference between OPTIONS 5 and 6 will be pretty subjective depending on the amplifiers used. I suspect Amp+ high power audio is cleaner than most mainstream aftermarket trunk amps out there.

[bradnic]

Ducky11 this is really the speaker and amp wiring thread, but really curious about the Mbus adapter. Sweet piece of kit there.
the CM5908 and KE83ZBM were both CD changer enabled but incompatible with each other.

This is the best info I've ever found on the original CD changer setups. There are multiple cable types depending on the changer used.
http://www.unofficialbmw.com/e34/ste...d_changer.html

As to the radio connector, they look the same but the pinouts are different. quoting the link above

When the a early CD ready radios came out in the E30s you could only use the Alpine with the Alpine changer and Pioneer with Pioneer. BMW's bulletin said:

"These components are only compatible with each other, the use of other components is not possible and may cause damage to either unit." The original CD for the Alpine was the drop down door 12 disc unit, later the shoe-box sliding door 6 disc unit, from Alpine. My info from AAMP says "aftermarket Alpine CD changers do not use the same command protocol as BMW's Alpine built changer. Consequently they will not work on any BMW system."

I don't have the 5908 pinout, but I do have the KE83:



It's possible the radio end of these cables is the same, in which case the radio connector pinout in the 2nd table MIGHT apply to the 5908. TEST AT YOUR OWN RISK though.

[Ducky11]

It's been asked a few times and I can't seem to find any real answers: Does anyone know the pinouts for the CM5908 CD player plug? I'm trying to make Maakbaas's bluetooth adapter work but CM5908 needs a customized cable. If I can find the pinouts I'm pretty confident I can make it work. Anyone?

[bradnic]

bradnic/jhaurimn,

Can you please look at my youtube video that I posted (post #34)? https://www.youtube.com/watch?v=lXYdEnJJVnU I performed (what I thought was correct) an amp bypass/Continental HU install on my 1987 325es. Car is an early model 2 channel setup, has fader in the dash and premium sound system.

Everything works perfectly (HU can be used for hours) but with your recent "correction update" I am thinking I did something wrong. Looking at timestamp 7:16 in my video for reference, I simply separated the stock violet wire (ignition 12v) from the stock brown/black ground wire(s) and connected them to my new HU ISO connector accordingly.

My questions is this, the stock brown/black ground wire was actually 2 wires. Just like the schematic says but I didn't separate them. I just hooked it (them) up to my new HU ground wire?

Is this a mistake?

So sorry I missed this post. I commented on your vid. GREAT JOB.

It would be great for folks to post pics of the 4 wiring setups in the 1st post. I will continue to add pics as I find them.

EDIT: added some comments to your video, cross-posted here

@2:32 those are both positive, blue/black for rear, blue/red for front. same for the yellow pair.
The 2 channel premium sound cars used a common brown/black ground wire between the radio and the amp. That wire was then grounded to the chassis. You can see all this in the 2 channel BMW Sound System schematics showing the "digital radio" and the "amplifier". There is no "speaker ground wire" going to the radio in this setup.

@2:59 you have brown/black wires connected to the positive speaker wires so you've ended up reversing polarity on each of those speakers. if all four are reversed then you won't notice a lack of bass from phase shifted speakers. I

t would have been cleaner to just do the 2 channel amp bypass in the r3v thread.
Here's what you could have done, under the rear seat, no need to cut the trunk harness and leaving all the speaker wires alone:
speaker + to radio +
- blue red to grey white (right front +)
- yellow red to grey violet (left front +)
- blue black to black white (right rear +)
- yellow black to black violet (left rear +)

speaker grounds to radio out ground
- grey brown, black brown, grey violet, black violet from speakers can be tied together, then to a separate added speaker ground wire run to the radio

chassis ground (keep separate from speaker ground)
- thin brown black to brown

[The_Glory]

Hello, colleagues.
Interesting topic.
I am going to install the original sound system with an amplifier.
There are several questions about it.
1. I have front speakers of a BMW, but from the E38 - with an additional pair of contacts for connecting a hands-free standard telephone. They do not have a coil of wire around the magnet. How critical is it? How to connect them correctly?


2. I still don't have the original rear speakers. There will be Clarion 2-way speakers temporarily. Everything is clear there with the wiring, but not quite clear with the connectors for the rear speakers on the wiring. Judging by the photo on the Internet, the same rear speakers were used on e23, e28 and e30, which had ordinary flat contacts and corresponding flat contacts on the wiring. My wiring has rear speaker connectors with cylindrical contacts. I received the wiring without number tags, with the main connector cut off and without the contacts of the front speakers - this is probably the result of the "mp3 upgrade" of the 2000s. But the rear connectors, apparently, are factory. What speakers is this wiring for? Is it not for E30? I saw the same wiring on the Internet, with the same connectors.



3. Where exactly is the ground, marked on the diagram in the ETM as G106, which comes from pin 10 of the amplifier connector, screwed? Judging by the wiring, - somewhere near the rear left speaker, but I don't understand exactly where... And also, - a separate terminal on the body of the power amplifier - is this also another ground?


PS
By the way, about the colors of the wires and the scheme. Apparently the schemes and colors for the European market are different from the American market. I (and all my other friends) have audio wire colors that do not match the colors listed in the American ETM. Also, we are completely missing the C243 connector. Is it used for an additional fader control?
It's a bit confusing, but I figured it out and de-foamed the radio and amplifier connectors. I can show it here later, but the text is in Ukrainian...

[andrewgrhogg]

OK people - resurrecting this slightly old and dead thread, just so i can add in what worked in my case. I have a 1985 325e, with the -2 radio - as in Fader, no amp in back, no tweeters. Not many people seem to have this set up and most of the posts here and on other forums are for the other systems.

So, here were the keys for my set up. Note that i was going for "good enough" sound, in an almost 40 year old car, that isn't the quietest machine on the road to begin with! As in, why would i spend a butt load of $s on an excellent sound system when the amount of "noise" in the environment is just going to impede on all those lovely high and low notes. I don't need thumping bass, and i don't need neighbours 3 blocks down to hear my music, but i do need clarity so i can actually hear the words and the individual notes, and i need it loud enough to hear when im driving with the windows down. And i wasn't looking to spend a fortune on a car that i could sell tomorrow for maybe $15k. So, here is what i did. Note that my stereo system was 6500-2, and everything was original including all 4 speakers and all wiring, and i had the original head unit still. No Amp!

1. Installed a new head unit - Continental TR7412UB-OR
2. Installed 4 new speakers - Rockford Fosgate R1525X2 using all existing wiring
3. Did not need to do any additional wiring, or burrow around inside the dash to unwrap wires etc.
4. All the balance and fading works fine, despite numerous people here and on other forums indicating it would not. I looked at the wiring diagram, disagreed with peoples thoughts on ground wires and shared wires not allowing different voltage drops to different speakers (Fade and Balance), wired it up the way i thought it would work, and bingo - it works fine. FYI i have a dual engineering degree, in Mechanical and Electrical engineering, so id like to think i have some idea what im doing! :-) In this case, i did...but no promises for the future...
5. The key for me was to do the following
a. Remove the Fader from the dash, and undo 4 of the 6 wires. I left the Yellow and Blue wires in the small harness, just as a way of keeping them from touching everything else. You could of course remove them and then tie them off. Neither wires is used in this configuration.
b. From the Fader, used the Yellow/Red and Yellow/Black (Left front and left rear positive speaker wires) and the Blue/Red and Blue/Black (right front and right rear positive speaker wires) and connected to the relevant 4 "positive" speaker wires from the head unit.
c. From inside the dash, from the wires that were connected to the old head unit, connected the yellow/brown (left front and left rear combined negative wires) to the two "negative" wires for the left front and left rear speakers. So this is three wires connected together.
d. From inside the dash, from the wires that were connected to the old head unit, connected the blue/brown (right front and right rear combined negative speaker wires) to the two "positive" wires for the right front and right rear speakers. Again this is three wires joined together
e. The blue and yellow solid wires from inside the dash are tied off so they dont touch anything. The yellow/brn and blue/brown are also tied off so they dont touch anything. They are NOT tied into any grounds.
f. The solid brown wire from inside the dash is connected to the ground wires on the head unit.


I think that covers all the wires, other than the power wires which people have mentioned above already. All the Fading and Balancing works fine, and even if you turn up the volume and have all the sound going to one speaker, there is no distortion etc. Note that if you have Zero sound set for two speakers using the balance or fade, that a little sound will still come out of those speakers. This is the joy of the shared negative wires for two speakers. However, you wont be able to hear it unless you stick your ear close to the speaker - so. not an issue.

This set up cranks sound, is clear on all notes, doesn't have speaker sound issues at full volume, allows Fade and Balance to work, has Bluetooth, will have the unit come on automatically when you turn the car on, and only costs $140 for speakers, and $174 for the head unit. And, most importantly, does not require running new speaker wire, or digging around in the dash unwrapping wires. The old adage stands true here - "Don't let perfect be the enemy of good enough".

[PNWE30M50]

bradnic/jhaurimn,

Can you please look at my youtube video that I posted (post #34)? https://www.youtube.com/watch?v=lXYdEnJJVnU I performed (what I thought was correct) an amp bypass/Continental HU install on my 1987 325es. Car is an early model 2 channel setup, has fader in the dash and premium sound system.

Everything works perfectly (HU can be used for hours) but with your recent "correction update" I am thinking I did something wrong. Looking at timestamp 7:16 in my video for reference, I simply separated the stock violet wire (ignition 12v) from the stock brown/black ground wire(s) and connected them to my new HU ISO connector accordingly.

My questions is this, the stock brown/black ground wire was actually 2 wires. Just like the schematic says but I didn't separate them. I just hooked it (them) up to my new HU ground wire?

Is this a mistake?