The next step with this car was to upgrade the factory sound system.  My days of high end IASCA systems are over but being in search of sonic ecstasy in the automobile is still a hobby.  In 1992 the factory sound system was upgraded a bit and instead of the factory head unit being made by Becker its made by Alpine.  This made locating a factory CD changer a bit more challenging, but I did manage to locate one on EBay that was new, came with the cover and all necessary cables.  Only thing it did not come with was the mounting bracket, so I had to fabricate some myself.  The MB cars are pre-wired from the factory with the CD changer cables and power cables.  In the case of the 190, the cables are located on the passenger side of the trunk behind the plastic cover near the tail lights.  This install was very simple:  mount the changer, plug in the cables and were done.  I installed the changer in the factory location that still leaves the small storage compartment usable.



Two of the factory speakers were blown and after further investigation, the right channel of the factory Alpine head unit was also blown.  So after a quick search of Ebay, I located another factory head out of a 93 190 and picked it up for about $60.  I don't really have step by step instructions for removing the head, but you need to remove the ashtray and then the two screws hidden behind it.  After that, the Zebrano trim panel pulls out.  The head unit is held in place by two tabs underneath, so if you use a small flat blade screw driver, you can bend them down (be careful, they are plastic and you don't want to break them) to slide the head unit out).  Anyway, after installing the new unit, I realized that now only the right output on my old deck was blown but the left side had a reduced output as well.  So, now I had a new fully functional head unit.

Ok, next up were the speakers. We all know the factory speaks blow, and to top it off, two of mine were blown (literally).  The factory dash speakers are 4" so after careful study of the available options and a few stops at local audio retailers,  I elected to pick up a set of Infinity 42.3I off of Ebay (specifically www.ikesound.com ) for about $76 dollars shipped.  These were by far the best sounding 4" co-ax I listened to.  I used the passive crossovers that came with the speakers but I added a 100 uf cap inline to eliminate frequencies below 200 Hz (6 db roll off).  You don't want any bass coming from these speakers.

On to the rear!  The newer 190's had a 5.25" speaker mounted in the rear deck.  The speaker is mounted in a plastic ABS housing that can be easily removed and modified to hold a aftermarket 5.25" co-ax.  I planned on picking up a set of Infinity 52.3i  5.25" but I had a set of Infinity separates sitting around and decided to use them.  Although things did not go as planned  ( the tweeters would not fit under the factory grills, so now they are sitting out on the rear deck) at some point, I will replace them. 



The grills can be removed by pushing them towards the rear window and lifting up, then you pull them forward.  Pretty simple.  To get the factory speaker pods out, there are two tabs that you need to push in, then these pods will come right out.  You need to have a dremel or some other similar tool to trim the pod to accommodate a different speaker.  I also used a silicone to secure the speaker in place and prevent any leaks.  I also used the factory crossovers and installed a 100 uf capacitor inline to filter out frequencies below 200 Hz.  Since  a single inline cap only provides a 6 db roll off, the overall tonal balance is very good.

Next I had to investigate the woofers mounted in the doors to see if these could be used to provide bass for the system (the system really needed it now).  The active bass system in these cars is powered by a separate amplifier mounted in the trunk.  Not sure of the power output, but it does have an internal crossover and only sends frequencies below about 80 Hz to the door speakers.  These speakers are housed in ABS enclosures and will not accept anything larger than a 4" woofer without serious modification.  Given that fact and the fact that even if I could fit a 8" woofer in there, the internal volume of the enclosure is not enough for anything larger than say a 5.25" woofer.  So, I scrapped that idea altogether and just disconnected them.  In my 300E I installed a bandpass enclosure and routed the ports up through the rear deck.  I started looking at this type of solution for the 190, but the trunk is much smaller than the 300 and I did not want to give up that much trunk space.  One thing nice on the 190 is that the first aid kit sits in a plastic tray that can easily be removed.  Ok, now I figured out how to get the bass into the cabin of the 190, but I still did not have a good solution.  I thought about a infinite baffle design with maybe a 8" or 10" sub, but I really don't like going that route unless I have a sub utilization a active servo control, something to control the excursion.  Well, back to the search, after a few more days I came across another product by Infinity called the Basslink.  It is a complete solution with 10" sub, 10" passive radiator, internal 200 watt amplifier that accepts high level inputs and is housed in a compact, light ABS housing.  The Basslink also has numerous adjustments for tailing the sound, an adjustable crossover, phase control and Infinity's version of active servo.  This sounded rather interesting so after visiting a few local audio shops again, I finally managed to get a listen.  This little cabinet had quite a impressive output,  very tight and detailed.  It packed quite a punch for so small a cabinet.  I took some measurements and found that it would fit almost perfectly under the rear deck and not go all the way down to the floor of the trunk, thus allowing me to carry larger cargo by sliding it under the Basslink!  Of course I was not going to buy this for $450 plus tax at my local Car Toys, so back to www.ikesound.com  and picked up a new one for $234 shipped to my door.  (I love internet commerce!)

The installation of the Basslink was not complicated, as you can see I mounted it directly under the first aid kit cut out and I used heavy duty tie wraps to secure it to the underside of the rear deck and the gas tank.  It is secure and does not move.  To help facilitate the sound getting into the passenger compartment, I removed the rear deck and carefully cut out the cardboard/jute material on the back of the first aid kit door.  Leaving only the carpet, I now had a acoustically transparent door that looks completely stock. 

Signals for the Basslink are provided by the rear speakers (high level inputs) since there are no low level signals available.  Using high level signal inputs allows the Basslink to turn on automatically when it detects a signal.  While this was a novel idea, it just did not work well, the turn on delay was long and the turn off delay was also.  When turning the system off, I was getting strange sounds coming out of the Basslink and of course, turn on thumps.  So fortunately this option can be turned off and you can use a regular +12 turn-on lead to turn the Basslink on.  I tapped into the door speaker amplifier +12 turn-on lead and routed it over to the Basslink. 

 

Ground was provided by a bolt next to the factory door speaker amplifier.  +12 power was run directly from the battery and I picked up a Monster Cable power kit from a local shop for $25.  It has about 20 feet of 8 gage power, 4 feet of 8 gage ground, 20 feet of 16 gage turn on wire, a inline 30 amp fuse, ring connectors, wire ties etc.  I attached the +12 power to the power junction box located next to the battery, in my pictures here, you see two fuse holders, one for the Basslink and one for my Valentine 1.  You can see the grommet in the firewall where I ran the power cable through, you need to remove the plastic cover from behind the battery to gain access to this grommet.  Ran the power wire down the passenger side foot well and up into the rear seat (seats were already out to remove the rear deck).  Not complicated but it did require a couple of hours to disassemble and make everything look nice.


I am quite impressed with the sound of the factory system now.  Its not going to win any competitions and the staging is a bit biased, but I am satisfied.  The bass I must say is very impressive, while I am not getting frequencies in the 20 Hz area (either its the Basslink or the factory system has some sort of sub-sonic filter, I am not sure) the response is deep and tight.  The active servo design does its job quite well and for the type of music I listen to  (house/techno/break-beat) there is plenty of bass.  One of the other nice features here, is there is virtually no vibrations from the trunk.  Almost all the low frequency energy is fired into the passenger compartment and is not bouncing around inside the trunk.


7/4/03 Head Unit Update

Given the fact that the majority of my music now comes from MP3's, over 140 songs can be burned onto one 700 meg CD-R.  This is almost double what the factory 6 disc CD changer can accommodate, so the factory CD changer was sold on Ebay for $190 and a Panasonic CQ-DFXP683U MP3 player was purchased ($141 from Ebay).  This particular head has an internal Mosfet 50 amplifier and a non-fading dedicated sub out.
 

We start by removing the ashtray and taking out two philips screws, the ashtray assembly lifts out and you disconnect the power cables on the bottom of the assembly.  There are two metal clips on the bottom of the factory head unit, you can use a small flat blade screw driver to bend these down as you push on the radio from behind (hope you have small hands!) do this on each side till the radio slides out easy.





On the later model W201's, the sound system consists of a two channel Alpine cassette that feeds its signals into a Y splitter, one pair feeds the door sub amp and the other pair goes to the console mounted fader, this splits the signals into front/rear.  One important item to note here, only the positive leads go through the fader, the grounds are all shared and not fed through the fader.  To use a 4 channel after market head unit (and bypass the manual OE fader) you really should run all new speaker wire and not mess with the original wires.  I ran new wires for the fronts and used the OE wires for the rear, but I had to tap into them BEFORE the fader.



Like I mentioned above, I tapped into the rear speaker wires here at the fader, this allowed me to power the rear speakers and still feed a high level signal into the OE amp for the door woofers.  The wire schematics from the service CD come in very handy for these types of projects.  If you don't already have one of these CD's, pick up one from Ebay, they can be had for $10-15.





To run new speaker wires to the front speakers, required removing them and feeding wire from the OE deck location through the glove box area (see next picture) and up to the speaker (right side).  These are the Infinity Kappa 43.5 co-ax, very nice sounding 4" speakers.






Here is what the area behind the glove box looks like.  You may not really need to remove the glove box, but I found it much easier to run and secure the new speaker wire.







Once I had removed the factory head unit, I removed the OE mounting clips, they slide right off and allow you to mount a sleeve for the new head unit.  As for the sleeve, normally you bend tabs inwards on the top, bottom and sides of the sleeve, in the case of our W201's, your really only going to get the bottom tabs to hold, none on the top and very little from the sides.

The Panasonic is almost ready to be slid into place.  A bit of testing to insure everything is working correctly.








The Panasonic fully seated and ready for some MP3's.  The color of this unit is a dark gray, not black and the illumination is blue, so it does not really match the yellow of the instruments.







Since the Panasonic has non-fading dedicated sub outputs, I ran a set of Monster Cable Interlink 400 signal cables from the head unit into the trunk to provide signals to the Infinity Basslink.  The passenger side carpet, door sill and plastic floor plate need to be removed.  You can route cables in the plastic OE trays, the tricky part is getting the wires past the seat belt.



 

Of course the rear seat needs to be removed.  Start with the bottom seat cushion, push up on the red tabs and the seat lifts right out.  The rear seat back requires you to remove three 8mm nuts and it will pull outward and then you push up.