Hi all fellow MBZ car audio enthusiasts.
Nothing makes me more mad and pi$$es me off more than when some car audio "pro" shop, who does not have the proper diagrams, books, or even the technical knowledge necessary to install a stereo system in our kind of unique W124 and W126 body cars, puts in an aftermarket system, and basically totally screws up the rest of the systems in the car, especially the anti-theft system (not to mention other issues).

Many car audio shops literally just "hack up" the wiring harness and , well, basically almost ruin the wiring by trying to install an upgraded car audio system.

I have had cars come in, one 1991 300E in particular, that the install shop actually ran a wire to the trunk and kept the old Becker head unit partially wired up (yes, in the trunk!) JUST TO KEEP THE ALARM FROM GOING OFF!!!!
Need I say, this shop was just horrible! I'm sure they were just fine doing an old Nova or Caddy lol.

I am a recording engineer by trade, and in the past AND present I have owned and worked on several 123's, 124's and 126's, and have done my own installs on audio as well as custom work for others.

I am here to offer my assistance to anyone who is in need , or has any questions about doing an installation by replacing your factory Becker with a newer head unit, upgrading speakers and amps.

Weather you decide to just replace your existing head unit, or decide to replace the whole system, Please shoot me an email.

I personally make some custom wiring harnesses that simply just plug into your factory harness.

No wire cutting, "tapping in" to wires, or splicing PERIOD!
And if you just have any questions, feel free to ask.
I will try my best to answer your questions. {I DO NOT charge for consultation on proper speaker sizes, recommended receivers and outboard gear, and I DO NOT sell new gear, so no worries about someone pushing you into something you may not need!} My main concern is that your Mercedes can be outfitted with a great system, without any permanent modifications, and can be returned to 100% stock if you choose to sell it so future owners are not plagued with wiring gremlins that an under-qualified stereo install shop may have caused.

The benefit of a proper install is, when you sell your car, it can be returned to 100% stock, and your original factory car harness will be UN-CUT and will simply just plug right back into your original factory Becker stereo.

I only do Mercedes W123, W124, and W126 cars.
Feel free to email me with any questions, wiring diagrams, etc to make your install go as smooth as possible.
I also have diagrams available for euro headlight conversions as well.
I am a W124 and W126 owner, and I am more than happy to help with that difficult stereo installation, or just to help by answering your questions.
Thanks !

Hey W126Ken
What would you suggest for adding a little umph! in the rear of an 83 300TD?
Size and manufacturer?
Price not really an issue, but stock from other body styles or even makes would be ideal.
I live at the local JY's.
Wanting to provide a little more low end without resorting to an amp/bass tube scenario.
Old rear speakers are trashed and asking they be put down.
Thanks.

Hollywood

First thing I would do is replace the stock speakers with a good pair of aftermarket ones like Infinity, JBL or MB Quart. Stay away from EBAY off-brands and department store cheapies.

I believe the rear speakers are 4" in your wagon. And the front should be 4" as well.

You might be able to squeeze in a 5" speaker in the rear with some minor mods, but I wouldn't recommend it.

You have basically two choices with any of these brands.

You can go with the standard co-ax 2 way style, or a component system. The main advantage of the component system is that you can mount the tweeter separately, rather than hide it behind the factory grille.

This adds to cleaner "highs" and a choice of where you want to place the tweeter so it can be heard.

The other advantage is with component systems, you get a crossover network that sends the lows to the woofers and the highs to the tweeters.

On some crossovers, there are roll-off switches that let you customize the sound of that speaker to the place it is mounted.

This is mostly useful if you plan on running a sub-woofer, in which case you do not need to send a full-range signal to the speaker, only midrange frequencies.

I also highly recommend you purchase a pair of XTC foam baffles that go behind the speaker (www.crutchfield.com).

These baffles help in so many ways.

First, it reduces road noise.

Second, keeps moisture away from the speaker, and most importantly, improves the acoustic properties of the actual speaker itself.

As you know, if you pull out your stock speaker, and look into the hole, it is just a big, open "void".

Mercedes did not design this area to acoustically enhance the speaker.

It was just a convenient place for them to mount it.

Raw speaker drivers, of any kind, be it studio, or automotive, are designed to be used within a certain enclosure size.

Most people who install car speakers do not take this into account when they do an install!

This is why I recommend using those XTC foam baffles I talked about earlier.

These will seal the rear of your speaker, giving it tighter bass and also cutting out any road noise that leaks in through that void in the cars body, and will actually make the speaker sound louder.

Lastly is how much power you are giving the speaker itself.

Believe it or not, you can do much more damage to a speaker by under-powering it than by over-powering it.

Make sure your receiver can deliver a decent amount of power, or even better, get a dedicated amp to power the rear speakers.

You don't need billions of watts to drive them.

A good, clean solid amp delivering 30 to 50 watts should do just fine. Just make sure if you do go with the dedicated amp route for the rear, that it is properly grounded to the car, and at least 12g wire is used for the amp's main power.

And, don't forget to shop around.

Good example is Crutchfield wanted over $100 for a pair of Infinity's for my W126.

I ended up finding them on-line for about $60 shipped!!
And, since I have had them, I have had no problems period.

Hope this helps!
Good luck on your project and please let me know how it turns out!

I have posted a couple of questions on this part of the forum with NO replies.
I was happy to read your comments on the 124 and 126 vehicles.
Can you help me with my 129?
Aren't the previous vehicles somewhat similar to the 129?
I don't know but I would love to replace my head unit and rear mounted amp with another head unit/amp and be able to use the existing speakers/wires and power wires, do you have any idea if this is a good idea?
I'm somewhat savvy but I don't want to buy all of the items and find out later it won't work easily.
Thanks for your postings, they are appreciated.
Steve

Ken, I forgot to mention, I live in the Cleveland Ohio area and I travel to Pittsburgh a couple of times a month.
Let me know if you might be interested at looking at my 129 when I come through town.
Thanks, Steve

Hi Steve-
I would be happy to look at your car next time you are in town.
I actually live about an hour north of Pittsburgh.
PM me and I will get you my phone number and address.

Hi Steve
The basic sound systems are quite similar to the earlier 126 and 124's, with some minor upgrades.

First thing to do is to upgrade the head unit and speakers.
Believe it or not, the factory amp in these are quite good actually.
With a new head unit and speaker upgrade, it will make a 100% difference.

As I said , first thing to upgrade is the head unit and speakers and then give your system a listen to and then make a decision if you want to upgrade the amp or not.

The factory amp does supply a good amount of power.

Enough power to drive almost anything out on the market today.

The factory speakers though, are still quite inadequate and very inefficient.

In my opinion, MB has never got the speaker and amp combo right.

The amps have always been well built, with lots of power, and the speakers just seem to be cheap units that distort and break up easily.

The best test to do with your car is to replace head unit and speakers, Leaving the factory amp intact, and take a drive with the top down and just make notes on how well it performs.

Its best to do two tests.
One with the top on, and one with it off.

The cars acoustics will most certainly change with the top off.

You will loose "reflected" sound, which makes the system seem louder than it actually is with the top off.

But with the right choice of speakers, this can be minimized.

I will be more than happy to help you in any way I can.

Well put and 100% agreed.
I am planning on replacing my speakers but haven't received any definitive suggestions as to size and model number of speakers that will suit a 1983 w126 300SD with minimal modification to speaker or car.

I can amp the rear, though for this installation I may just utilize head unit power.

Do you have model # recos for front and rear for this car?

Thanks for your post!

__________________
This area is typically used to brag about one's current or former automobiles.

The front speakers, as well as the rear speakers in the pre-1986 W126 cars are 4"x6".

If you want to replace all of them , without any mods, I would suggest the Infinity Reference 6412CFP.

They are a perfect fit in the front and rear as well.
They are a two way "plate" style speaker, meaning both the mid bass driver and tweeter are mounted on a 4x6" plate with various mounting holes for different bolt patterns.

I have a pair in my front dash and I am very happy with them.
They can be had on-line anywhere from $30-$50.
I do recommend getting a pair of the XTC foam baffles I mentioned earlier to use in the front dash, and a pair for the rear deck.

Any good head unit with at least 20 watts of power will drive these speakers without the need for an amp.

If you do want to modify the rear deck, you may be able to fit a pair of 6 1/2" speakers, but this may require some cutting of both the deck and the sheet metal below, which I do not recommend.
The Infinity 6412's will give you great sound.

If you require a little more bass, you might want to consider a small sub-woofer.

Both JBL and Infinity make small units, and one of them is small enough to hide under your front seat, but if you do decide to use a sub, you will need an amp to power it.

All head units on the market today cannot supply both the watts and current that are needed to drive a sub properly.

Personally, I think you will be amazed at just how much of a difference just replacing the dash and rear deck speakers alone will make.
Hope this helps.

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Need help. Read here:
http://www.peachparts.com/shopforum/showthread.php?p=2384643#post2384643

I have a 1991 300SE and want to replace all of the speakers and head unit.

How many speakers and what size are they, also what would be the best speakers to put in the car.
Thanks,
Sba121400

The previous owner of my 300E chopped the old wiring harness to pieces [including removing the front/rear fader]

Up inside the dashboard, he used wire nuts to connect the power and front speaker wires.

I need to resolve some engine 'sudden death syndrome' problems first, but this spring I will want to rewire the stereo, using as much of the factory harness that has survived.

Your front speakers will be 4x6", and the rear will be 6 1/2". Personally, I would go with the Infinity reference series speakers, since they went into my car without any issues.

Now it is tricky to do the rear speaker.

Here is why.

When you remove your stock rear deck 6 1/2" speaker, you will notice that it is mounted in a plastic riser, that also serves as its mounting. it is very important that you save that part to mount your new speakers in.

The stock speakers can be easily removed from this mounting plate / riser. The stock speakers are just glued in.

As for a replacement head unit, I like the mid-range Pioneer units.

I have had several of them, and have never had a problem.

One question I do have, does your stock system have the "premium" sound system installed?

The easiest way to tell is that you will have sub-woofers mounted in the front doors.

If you do have the premium system, It will be a bit more work installing a head unit since all of the speakers are driven by an outboard amplifier.

I know exactly what you are talking about.

It is quite common for people who are unfamiliar with these cars to just ruin the harness.

I have had so many 124 series cars come in after having a store like Best Buy or Sears do an install.

Cutting wires that they do not know what they go to ...etc.
They have no idea just what wires actually run through that harness.

Wires from your SRS system and security system, just to name a few shares that harness.

Anyway, the best thing to do is to back trace the wires from the speakers backward.

The front and rear speaker wires should run back to the fader control, and then from the fader control to the radio.

Make sure you properly repair any splices that they put in.

I recommend using heat shrink tubing and soldering your wires back together rather than using crimp type connectors.
Crimp connectors can corrode after time and will cause you , or the next owner problems.

Once you solder and shrink wrap the wires, bundle them back up and I would suggest using 3M brand "friction" tape.

It closely matches the wire wrap used on your car.

Any good electrical supply outlet should be able to supply you with the proper wires, in the same colors as the ones in your harness going to the speakers and radio.

Ken,
I just purchased an '84 300SD and it still has the original Becker stereo and speakers.

Needles to say a upgrade is in order!

Luckily I came across this forum and found you, so I would like to order one of your custom harnesses so I can do this install correctly and maintain the car in its original condition.

How much do you charge for it and any other advice would be greatly appreciated.
Thanks!
Jaeson