108 hi-fi: by-passing fader - PeachParts Mercedes-Benz Forum

jas2wa · #1 08-04-2003, 02:40 PM

I've posted a thread in the audio discussion section about the 108 audio system in general, recommendations for replacing it, etc. Since the car is old, I thought I would post a fader-specific question here- in that, how does one effectively bypass the dash-mounted fader knob? Archive searches have yielded no specific answer, esp. relating to the 108 chassis. Seems nobody has done much with updating the sound in their 108's (at least not those browsing the audio forum...)

Thought I might get more response posting here- any suggestions? BTW- I am not talking about anything more than updating- and using stock openings and speaker grilles, etc. Low-profile improvements, if you will-

Thanks,

JAS

Mark DiSilvestro · #2 08-04-2003, 08:00 PM

My '72 250 came with a Becker Europa 4 speaker stereo radio, with the separate fader knob mounted in the center console. There was no dash speaker. After the original unit died, I replaced it with a Europa cassette radio out of a 1980 240D and added a pair of 6 x 9 coax speakers in tne under-dash fiberboard covers to replace the crappy little 3" Becker surface mount speakers that were on the footwell kick panels. I kept the Fader.
On my original fader setup, all 4 speakers plug in to the fader. Couldn't you unplug the 4 speakers from your fader and connect the 4 channels fom your new unit directly, either with custom made terminals or, if you're in a hurry, cut and splice to the speaker wires. The factory twin-lead speaker wire is marked for polarity, so be sure to observe that when you connect the new unit.

Happy Motoring, Mark

ctaylor738 · #3 08-04-2003, 09:41 PM

I am assuming that you have a Becker Europa II stereo with speakers in the kick panels and package shelf. If you want to stay with the Becker, you can replace the front speakers with any good high-efficiency 4" two-way's, and the rear with some 6-incher's. Again, everything needs to be high efficiency because the Becker does not have a lot of power.

Why do you want to bypass the fader?

You can add a CD changer that feeds into the FM tuner.

Ed Ebel at Becker (eebel@beckerautosound.com I think) is THE authority on upgrading the older sound systems.

jas2wa · #4 08-05-2003, 09:10 AM

Thanks fellow Virginians-

I've already replaced the 4" speakers in the front footwells, need to do the pair in the rear shelf (4x6's). What to do with the center loudspeaker in the dash, though? I was thinking a pair of small tweeters mounted in the same space.

The Becker Europa is going- to be replaced with a brand new unit. As such, the fader needs to go, too- at least on my 123 chassis cars, the fader is run by just a single output on the new head unit, split between 2 pairs of speakers. Bypassing it allows the head unit to power both pairs of speakers independently. With the fader still in place on my 84 TD, the Blaupunkt head unit powers all four (admittedly small) speakers through one speaker output (for example, just the front speaker output). The fader splits it between 4 speakers. And it sounds like crap as a result. Much is lost through the fader it seems, esp. in my 108, which broadcasts a bunch of extra noise through the speakers while truning it...
Again, the wiring might be different on the 108 chassis car with fader, just not sure yet.

I use the car as my primary vehicle, and want to upgrade it as such. Will keep the old Becker for originality, should I ever want to re-install it.

JAS

Mark DiSilvestro · #5 08-05-2003, 10:14 AM

My 'upgrade' Becker Europa cassette only has the 2 speaker outputs, as did the original stereo Europa, so the fader works fine to power my 4 speakers. With a modern radio that has the 4 speaker outputs and fader built in, you would want to bypass the external fader. The fader in my '72 250 uses those German twin-pin speaker plugs. If I was bypassing it, I'd rig up matching connectors so I could plug the new radio's 4 speaker harness directly into the original factory 4 speaker harness.

I wish you luck on your stereo upgrade. It took a lot of experimenting to get decent sound in my '60 220S, but I had NO factory speaker mounts, not even one on the dash!

Happy Motoring, Mark

jas2wa · #6 08-05-2003, 10:25 AM

Mark-

Yes, you've explained succintly exactly why I want to bypass the fader.

Gee, I guess I have a pretty easy "bolt-on" job ahead of me, what with 5 factory speaker locations and all. Where did you end up mounting speakers in your 60 220? Just curious.

JAS

ctaylor738 · #7 08-05-2003, 11:03 AM

Sorry - I thought you were going to keep the Becker head unit.

First, if your car orginally had a Europa stereo with the four speakers, then I believe the dash has a blank in it.

Next, if your fader is orginal, it takes R and L from the head unit and balances front and back only. We have had 123 cars and I agree with your comments on the fader wheel, but the older ones seem to work better. If you don't use it, you will have to extend the wires from the speakers to the fader to reach the head unit, OR, run new speaker wiring. If your fader is worn out, you can buy a new one from Becker.

Hope this helps.

Mark DiSilvestro · #8 08-05-2003, 11:04 AM

For the radio I installed a mono Becker Europa in the dash and a single 6 x 9 Philips speaker in the under-dash fiberboard cover, behind the glovebox. It's pretty feeble but for now it's adequate.

I didn't want to cut holes in the doors or rear shelf so my 'real' sound system is a pair of 2-way 50 watt 'cube' speakers that are just small enough to fit under the front seats. They're powered from a small 100 watt amp that fits behind the dash. The amp has 2 RCA jacks to plug in an adapter cable from the headphone output of a Sony Walkman (or CD or MP3 or any other music source that has a standard headphone jack) It sounds much better than anything else I've tried, though the sound is mostly coming from behind me and there's some loss of treble under the seats.
For more treble, I can always pull the speakers out and set them on the back seat.

I'm now wondering if a powered subwoofer under the seat and a pair of inconspicous tweeters in the footwells would sound even better.

Happy Motoring, Mark

jas2wa · #9 08-05-2003, 11:45 AM

A blank in the dash? Interesting. Does leave me a nice spot to add something there, though.

Okay, I have already spliced the new footwell 4-inchers into the exsiting wiring. If I run new speaker wire to a set of rear shelf speakers, up to the area of the fader, I should be able to tie in the front speakers with the existing wires from the fader, and the new wires from the rear, right? So, that would give me fr and rr speaker wires to tie directly into a new head unit, skipping the fader.

Adding another set (of tweeters, likely) in the dash spot would require just another set of speaker wires to tie into the head unit (in conjuction with the fronts)? Am I over-simplifying this...?

Thanks for your thoughts on this-

JAS

ctaylor738 · #10 08-05-2003, 12:24 PM

If you have two front and two rear speakers, and you run four sets of wires to the head unit, you are good to go. You will control both fade and balance from the head unit and the factory fader switch will be out of the picture.

My thoughts -

Adding additional speakers? Beyond my competence. But from my previous experience, at that point you need to go to a more elaborate setup, including an amplifier, that allows you to tune the frequencies going to each type of speaker. Location is important, and I have been told that mounting tweeters below the dash doesn't do much because they need to be closer to ear level.

Personally, if I had made the decision to go with a new head unit and planned to keep the car for a while I would add an amp and possibly a kicker, and go with some speakers that can use the additional output. The 108 is a big car and not particularly quiet, so more power will improve the sound quality.

The 108 is also not a car where pristine originality is demanded, so I would think that a well-done sound system would recover most of its investment.

jas2wa · #11 08-18-2003, 10:12 AM

Update-

Have the car apart, putting in a slick system, all hidden under stock grilles and etc. Need to figure out how to take the fader knob off the dashboard. I have no directions for this, and I don't want to mess up my very nice wood with clumsy maneuvers...

Anyone know how this thing attaches?

-JAS

ctaylor738 · #12 08-18-2003, 11:03 AM

I'm travelling, so I can't look. These knobs usually attach one of three ways: a small set screw on the side, a nut under the center cover (pry off), or friction (give it a good tug).

jas2wa · #13 08-18-2003, 11:18 AM

Oh, sorry- I got the actual knob itself off (it was a little set screw btw)- looking to pull the whole thing out of the dash to get at the wiring-

thanks,

JAS

Mark DiSilvestro · #14 08-18-2003, 04:31 PM

usually, there's a chrome nut surrounding the shaft with a slot for a blade or holes for a pin wrench. In the past, when I've upgraded sometimes I had good luck with just dropping in new speakers. Sometimes it took alot of experimenting with speaker shapes, sizes, mountings and locations. Hope your speaker/radio upgrade is succesful.

Happy Motoring, Mark

jas2wa · #15 08-19-2003, 02:35 PM

Trying to decide whether I should run new speaker wires, by-passing the fader, or if I can get away with: 1.) determining what sets of wires control what speakers at the fader and 2.) extending those four sets of original speaker wires from the fader to the new head unit. I do have to add speaker wire from the pair of tweeters I am mounting in the front center location to the head unit.

As long as I can figure out what original wires go to what speaker location, I could save a lot of re-wiring.

Any thoughts?

Have to take the fader out and inspect when I get home-

-JAS