I’m attempting to install an aftermarket head-unit in my son’s 93 400e. The car has 6 speakers, 2 in the front window, 2 in the front doors and 2 in the rear. It seems the more I research this issue the more confused I get. From what I can gather, the front/rear speakers are 4ohm and the doors are 2ohm subwoofers.

The aftermarket radio is 4 channels (52x4 with two mono outputs for subwoofers.) Head unit has 4 RCA jack outputs and two mono subwoofer outputs – in addition to the standard color coated wires for speakers (52x4 channel).

Which scenario would you choose?

(1) Just run a couple of wires from the aftermarket head unit to the MB amp in the trunk. I could use only two of RCA Front/Rear Preamp Outputs with hi-pass filter head unit to the MB amp in the trunk. Or just use two radio’s channels/speaker wire connections 52x2 to run to the MB amp in the trunk. (I’m wondering it I would need a line/power adjuster before the amp.) And continue to use the existing front/rear fader control in the console.

(2) Run the front and rear window speaker with the 52X4 channel wires and use the mono plug on the head unit plug to run to MB amp which will power the MB door subwoofers (2 ohms) speakers. (I don’t know how this option would affect the front/rear fader control on the MB console.)

(3) Run the front and rear window speaker with the 52X4 channel wires and use the mono plug on the head unit plug to run to an after market mono amp to power the MB door subwoofers (2 ohms) speakers. This scenario would totally bypass the front rear fader.

Geeze… MB doesn’t make it easy for this year model.

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Russell McMahon
Tulsa, OK
2001 CLK 320
1992 400se
1993 400e
2000 320ML

to do it right, don't use the mb amp.

Rewire the speakers and run them off the Headunit.

Alon

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'92 300CE - Sold
2004 C240 - 744 - C7 Wheels - Android Radio
2002 C320 - 816 - Sport Wagon

While not easy or cheap, my suggestion would be to:

1) Run RCA cables from the head unit to a trunk-mounted aftermarket amplifier (multichannel). Don't skimp on the cable quality, and run the cable down the driver's side, because the main battery cable on a 400E goes down the passenger side (possible noise problems).

2) Do not use the deck power for anything! I'd also bypass the stock MB amps.

3) Run new speaker wire from the aftermarket amps to the speakers, but do not cut or modify any of the stock wiring - this will allow you to return everything to stock if desired

4) Replace the dash speakers with Rainbow coaxials. They are the only, and I mean ONLY, 100% drop-in replacement speaker for the W124 dash. The stock rear speakers are fine. The stock door speakers are ok unless you want to plunk down ~$750 for the nifty Jehnert dual 6.5 door panels.

5) You can use the now-defunct space where the fader wheel is, and swap in a switch to use as a valet switch for the stereo, or control a radar detector, etc as shown here.


FYI - the "52 watt x 4 channels" is usually rated a 10% THD, the deck is probably more like 10 watts RMS from 20-20k Hz at less than 1% THD. I'd look for a nice 5-channel aftermarket power amp, made in USA (Soundstream, Precision Power, Orion, Rockford, Xtant, etc). Something 25x4 plus 50x1 would be the minimum I'd recommend. Most multi-channel amps have decent built-in crossovers as well. For some photos of my not-yet-completed W124 stereo install, click here.




HTH,

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Dave
Boise, ID
Check out my website photos, documents, and movies!

GSXR..... Thanks for the suggestions and great installation pictures on your website! WoW.. I took a look at some of the other pictures of your cars in other directories on your site – YOU’RE A PRO! Do you customize cars for a living? I was very impressed with the “before –and- after” photos of parts and projects. I’ll say one thing, you don’t cut any corners, you do it right the 1st time. I wished you lived closer to Tulsa.

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Russell McMahon
Tulsa, OK
2001 CLK 320
1992 400se
1993 400e
2000 320ML

Hi Russell,

Hey, thanks for the kind words. But nope, I'm not a pro, just an anal hobbyist. I've done a number of less complex installs on previous cars, and I was usually not happy with the results unless it was done "right". So on my blue '87, I wanted to do it "right"! The white '87 was a guinea pig, a testing grounds to see what worked & what didn't, before I touched the blue car. That was where I learned that midbass speakers in the front door are *required* to get decent transition from the dash speakers to a subwoofer in the trunk - that car just didn't sound right without them. I also learned that making a baffle plate for dash speakers is a massive waste of time, just buy the drop-in Rainbows; and that 4ga cable can be fed through the wire trays under the passenger seat, and other little tidbits. Anyway, I've learned over the years that if I don't do it right the first time, I end up having to do things all over again later, which is just not worth it. That's why the blue car still isn't finished! I haven't had time to fabricate the amlpifier board and permanently mount everything back in the wheel well. I may need to add some cooling fans as well. Stay tuned for more later.

Oh yeah - my silver car (E500) came with the custom stereo system already installed, I just swapped the head unit out, and improved the fitment of the dash speakers where the "pro" shop did a sloppy install. I wasn't crazy about the rest of their work but it was "good enough", to where it wasn't worth my time to UN-do it all and then RE-do it. I need to post photos of that setup, I just haven't gotten around to that yet. There's a couple of photos in the 'prepurchase' directory, but not many.



Best regards,

__________________
Dave
Boise, ID
Check out my website photos, documents, and movies!