Need help installing head unit. 93 model year

[jeff0093]

Hi I picked up a new head unit would like to use the factory Amp/ Amps does some one make a factory amp adaptor for the gray Amp wire or is another recommended way to hook this up. I had it apart but put it back together.

 

[gsxr]

Sorry... installing aftermarket head units in 1991-1993 model years is a nightmare. There are no plug & play adapters. You need to run an antenna extension lead from the trunk to the head unit, and usually need to add an external power amp with new wires to all speakers. Then you'll have issues with trying to figure out how to cross over and impedance match the front door speakers (which are 2 ohm, IIRC)... all this magic was built into the factory amps. If it's not done properly, it will sound WORSE than the factory setup. (Don't ask how I know.)

Unless you're looking for IASCA competition-level sound, I'd send the stock head unit to Becker and get the auxiliary input jack upgrade (~$200). This lets you use an iPod or other MP3 player as an input source, retaining the stock head unit and power amps. The factory system is quite good, and unless you're prepared to dump ~$3k into Jehnert doorboards, complete rewiring, and aftermarket power amp(s)... I'd keep the factory stuff. BT, DT.

Rainbow Audio has some nice German-made 120mm front coaxials that are 100% drop-in for the dash, if you want to brighten things up a bit. Almost nothing else fits properly in the oddball, metric-size dash hole. The factory rear speakers with dual tweeters are excellent, changing them is a great way to get worse sound. The door midbass drivers are an odd size & shape, I've not yet found anything that fits properly... I'd leave those alone too. Factory amps are 25 watts RMS x 4 channels (100wrms total), which ain't bad... pretty sure it's a Bose system.


:listening_headphone

 

[2phast]

I don't believe 3k is necessary to replace the factory sound system. Start with a high end head unit, one with at least 40 watts rms (Mosfet). You can use this to run your front/rear speakers. Now either scrap the door speakers altogether, or get a small aftermarket amp (25 watts or so). Replace the speakers in the door pods with something that has 2" or less requirement for mounting depth (these will probably end up being full range speakers when your done, don't count on them for low freq.). For low end, run a powered sub. For your front rear speakers, again use high end stuff. 4" coax in the front and 5.25 in the rear (these will require a bit of modification to fit)

On the topic of head units, like I mentioned, go with a high end one that has extensive sound field processing built in, that way you can dial in your sound stage and optimize it for the driver.

 

[quicksilver500]

If you are not afraid of running wires, just run new speaker wire from the head unit back to the amp and tie in at the amp connector for each speaker, there will be 4 wire sets for 6 speakers. This gives you power and ground at each speaker. You can use like a 9v battery to figure out which is which. My brothers car w128.028 (mine previously) has been running an alpine unit for 8 years now with no issues wired like this. Everything else you can just splice in at the dash, all the other powers and grounds. You don't need the factory amps as long as your speakers ohm to ~3ohms.

I just did my w126, wired from the head unit all 4 channels to the rear amps, speakers ohmed out @3.2ohms which is fine for a 4ohm unit. Didn't run a antenna cable, I found that when I hooked the antenna up to power it acutally pulled signal, and when I unplugged power it dropped signal. So didn't need to run an adapter for the antenna, just using the power lead. I ran my IPOD and USB hookups to the center console.

-Mike

Also, w126 stock speakers kick 124 speaker butt.

 

[gsxr]

I should explain: Yes, $3k is on the high side. But if you ditch the factory door speakers, you lose quite a bit of bass / bottom end. Getting anything to work properly with the factory door speakers is very difficult (external amps / crossovers, lots of tuning). Adding a power sub in the trunk helps the lower octaves but still leaves a gap in the midbass range in the front soundstage. To do it right, you need custom door panels (like Jehnert) with one or two good 6.5" midbass drivers per door. That alone can be $1k for quality stuff, most people do not have the skillz to fabricate their own doorboards. Quality amps, head unit, labor to install, etc adds up fast.

IMO, a powered head unit driving the dash & rear deck speakers alone, will sound worse than stock. I still think getting the Becker 1432 mod with auxiliary in, and retaining the stock amps & door/rear speakers, with (optional) Rainbows in the dash, is the best bang for the buck. This retains the ability to run the CD changer in the trunk if desired:
http://beckerautosound.com/1432-1991/aux_input.htm

For the record... I have two cars with full Jehnert systems and separate power amps, several cars with all stock speakers & head units, and one 1992 where the head unit was replaced with aftermarket plus power amp feeding the stock door speakers, Rainbows in the dash, etc. The 1992 car sounds the worst, as it doesn't have the impedance correction and equalization built in to the factory amps. MB and Bose did a pretty good job with the factory stuff, and it's easy to make it worse if you're not really careful. YMMV, etc.

 

[2phast]

I should explain: Yes, $3k is on the high side. But if you ditch the factory door speakers, you lose quite a bit of bass / bottom end. Getting anything to work properly with the factory door speakers is very difficult (external amps / crossovers, lots of tuning). Adding a power sub in the trunk helps the lower octaves but still leaves a gap in the midbass range in the front soundstage. To do it right, you need custom door panels (like Jehnert) with one or two good 6.5" midbass drivers per door. That alone can be $1k for quality stuff, most people do not have the skillz to fabricate their own doorboards. Quality amps, head unit, labor to install, etc adds up fast.

IMO, a powered head unit driving the dash & rear deck speakers alone, will sound worse than stock. I still think getting the Becker 1432 mod with auxiliary in, and retaining the stock amps & door/rear speakers, with (optional) Rainbows in the dash, is the best bang for the buck. This retains the ability to run the CD changer in the trunk if desired:
http://beckerautosound.com/1432-1991/aux_input.htm

For the record... I have two cars with full Jehnert systems and separate power amps, several cars with all stock speakers & head units, and one 1992 where the head unit was replaced with aftermarket plus power amp feeding the stock door speakers, Rainbows in the dash, etc. The 1992 car sounds the worst, as it doesn't have the impedance correction and equalization built in to the factory amps. MB and Bose did a pretty good job with the factory stuff, and it's easy to make it worse if you're not really careful. YMMV, etc.

Since I classify myself as an audiophile, I have to disagree with pretty much everything you said AND yes, I have built many IASCA winning sound systems; http://2phast.com/porsche1/default.htm

Ditching the door speakers does not lose anything in the W124. In their original form, they poorly reproduced low end. You don't need them if your going to run another form of sub woofer arrangement. In my own car, I run 5.25" coax in the door cavities (with a separate ADS 25 watt amp) and this required a special "shallow depth" speaker, but because of their placement it does not add to the sound stage. So if I were to do this again, I would not even bother using them.

You can effectively run a 4" coax in the dash and a 5.25" in the rear (even a 6.5" if you want to cut even more sheet metal). If you choose a proper head unit that has internal electronic crossovers, you can create a band-pass and run them electronically filtered from 150hz (upwards to their cutoff or the cutoff of the passive xovers) at a 18db cutoff. Your sub can also be run from 180-150hz (down). You can achieve a very balanced sound stage with no gaps in your frequency spectrum. (verified on my spectrum analyzer)

When I say to choose a high end head unit with a internal 40/50 watt amplifier, were talking a MOSFET design output stage. This is MORE than ample to power four coax speakers assuming of course the 1w1m efficiency of the speakers are 89db or above. The higher efficient of your speakers, the less power you actually need. (FWIW. To increase sound by 3db, you need to double the power, so it is highly beneficial to start with high efficiency speakers). Maybe Dave if you run a low quality head unit in this configuration, then it might sound worse than stock (and stock is pretty bad) but again, were not talking some $75 cheapo head unit.

The digital signal processing of high end head units takes the place of external crossovers, eq's and other dynamic range processing devices. This Pioneer is a excellent example of what I am talking about (I use a slightly older version in my car).

http://www.crutchfield.com/p_13080PRS/Pioneer-DEH-80PRS.html?tp=5684

With proper design and some knowledge of system architecture, you can put together and very nice sounding system on moderate budget.

 

[JordiC]

With proper design and some knowledge of system architecture, you can put together and very nice sounding system on moderate budget.

+1, Although this requires years of experience which most members don't have. I also agree with the Pioneer 80prs, the best bang for your buck H/U available. It's amazing what can be done with simple time alignment of properly x-overed system.

I still would like to hear those Jehnerts paired with the 15"s

:razz:

 

[8899]

On the topic of head units, like I mentioned, go with a high end one that has extensive sound field processing built in, that way you can dial in your sound stage and optimize it for the driver.

I just picked up a head unit for my car. I was specifically looking for something that is close to period-correct for the E500E and was specifically looking at the Alpine 7909, NAK cd700 and the Clarion DRZ9255 and ultimately chose the Clarion based on some of these reviews:

http://www.diymobileaudio.com/forum...-comparisons/2586-clarion-drz9255-review.html

http://www.diymobileaudio.com/forum...t-shootout-time-data-looking-headunits-2.html

I think the Clarion will mate nicely with my, also period-correct, xTant 3300c amp.

 

[gsxr]

+1, Although this requires years of experience which most members don't have.

Agreed. If you have the experience, you can probably change to aftermarket components on a moderate budget.

What I still disagree on is that the factory system is bad in the first place. It's really quite decent.

 

[Egreaves20]

I ran wires from head unit to trunk and tapped into the wire harnesses that used to plug into the amps. Relatively easy to do and saves a lot of headache.

 

[jeff0093]

Sorry guys I was away, I don't want to go that crazy with the Stereo on this car, I think the stock amp and speakers sound fine, I was just looking for a new head unit for the Bluetooth aspect. I think I'll send my unit off to Becker for the MP3 upgrade and install the front dash speakers that I picked up on here and call it a day. I have a very nice sound system at the house so I can get my music fix at home. I also don't want to cut or hack anything on the 500E anyway. thanks for all the advice. Does Beckers offer any other more modern plug and play units?

 

[gsxr]

Does Beckers offer any other more modern plug and play units?

Sadly, no, at the moment Becker does not offer any more modern head unit as plug & play for the 1991-1993 models with 1432 head unit. And that's a real shame. I wish they would come up with a converter box that would allow the newer units to work with the stock amps. It wouldn't hurt to ask them if they have any plans to create an adapter to allow newer head units in place of a 1432, but don't get your hopes up.

 

[gerryvz]

Also, w126 stock speakers kick 124 speaker butt.

Y'all got that right ... particularly the later (1989-1991) more advanced W126/C126 systems.

There is no easy plug-n-play solution from Becker to replace the 1992-1993 model year US systems. Luckily us 1994 owners are in luck and have a plethora of P-n-P options from Becker.

Cheers,
Gerry

 

[jeff0093]

Becker DTM 7910 what about this? they said it was a plug and play except for the antenna wire? I called them in NJ. $550 for the head unit.

 

[gsxr]

Becker DTM 7910 what about this? they said it was a plug and play except for the antenna wire? I called them in NJ. $550 for the head unit.

That is plug & play on 1994-up models which had the 1492 head unit from the factory.

Pretty sure they made a mistake, make sure you tell them you have the 1991-1993 two-piece factory radio with the tuner in the trunk.

Check out the photos.



This is the 1432 which you have in your 1993 500E:

This is the 1492 which is used on 1994-95 models:

And this is what the business end looks like on pretty much all of the newer Becker head units, with minor differences between models:

 

[jeff0093]

I called Becker in NJ today and left a voice mail, weird I talked to them on Monday, but no answer today on all three of the phone lines on the web site? Anything I should know?

 

[jeff0093]

So now I can't find my radio code in any of my paperwork, I know I had it, whats my next step call parts department at the dealer. Do I need just the vin or numbers off the radio?

 

[gsxr]

The dealer just needs the VIN... the code will be on the VMI report. This assumes you have the original radio, btw.

 

[jeff0093]

Got the code thanks for the info, it's very nice the dealer can pull the code by the Vin and I didn't have to pull out the radio again. Removing the stock radio took 8 mins and was a real pain I thought I was going to break things.

 

[oaklandw124]

Spoke to Stefan at SW Stereo(www.swstereo.com) a while back as I had a 1432 in my 1992 300SE. He said he could make an adapter that would connect an up to date head unit (like the blaupunkt San Francisco 320 or Toronto 420) without cutting wires, etc. He then would send an antennae extension cable that you would route along the passenger side of the car so the antennae would work correctly.

Is it the general consensus that, even with a solution like this, the end result would not be as good as the factory system?

 

[gsxr]

Spoke to Stefan at SW Stereo(www.swstereo.com) a while back as I had a 1432 in my 1992 300SE. He said he could make an adapter that would connect an up to date head unit (like the blaupunkt San Francisco 320 or Toronto 420) without cutting wires, etc. He then would send an antennae extension cable that you would route along the passenger side of the car so the antennae would work correctly.

Is it the general consensus that, even with a solution like this, the end result would not be as good as the factory system?

It's hard to say, because I'm not quite sure how he is making it work. I'd like to see the adapter cable. It may be possible, and it may sound good. I've just never seen anyone pull this off yet and report it on the forums, but that doesn't mean someone hasn't done it! And, I would LOVE to know how to do it, if possible.

BTW - the antenna is the easy part, you just add an extension, as he said.

 

[oaklandw124]

It's hard to say, because I'm not quite sure how he is making it work. I'd like to see the adapter cable. It may be possible, and it may sound good. I've just never seen anyone pull this off yet and report it on the forums, but that doesn't mean someone hasn't done it! And, I would LOVE to know how to do it, if possible.

BTW - the antenna is the easy part, you just add an extension, as he said.

Thanks, Dave. I don't know much about this audio stuff, but it might be worth it for you to give him a call and see how he does it. If it makes sense to you technically, might be a good alternative for members of the forum to explore. His number is 800 - two 7 zero two 3 7 eight

 

[M104-AMG]

Both '93 500E's don't have the stock head-units or amps. As such, can someone take a picture of the receiver & amp for a '93, and it's location ?

Thanks,
neil

BTW: I found these on the Becker site:

I'm on the Becker site and supposedly these are the two full-range amplifiers:
http://www.beckerautosound.com/1432-1991/124 300CE_E amp.html

Also, some W124's (TE and diesels ?) had this bass amplifier (it's black in color):
http://www.beckerautosound.com/1432-1991/124 300D amp.html

Am I correct in saying the 1993 500E's had the two full-range amps ?

Thanks,
neil

 

[richardhilton590]

I remembered when I had mine installed, everything was a mess after. I suggest you bring it to your techinician if you are not so good on such things!