braddman

After I was an idiot and couldn't figure out the simple diagram I decided to make a video and upload it to my channel. This explains the color codes and how to hookup an aftermarket amplifier to the factory or aftermarket speakers. I've also attached my personal translation of the document and the original document here as well as an attachment.

https://www.youtube.com/watch?v=s29CnCzAUxo

dRockSL55

Very helpful, though I think you have the polarity for the mono fill speakers reversed (BK ground, BK/GN positive - refer to the component chart on right that describes the z28/1 and /2 splices)

braddman

Thanks, I'm not sure that's the case. The polarity isn't mentioned and in every other case the dual color is the negative. The rear fills are weird..I have not figured out why they both have the same colors?? I know they have different wires actually going to the speakers.

latemodel21

it is a single "rear-fill" channel. The 2 speakers are wired in parallel. Worth noting, early R230s (through 2004?) had the splices near the speakers (making it more of a challenge to isolate them thereby re-tasking them as rear right and rear left)

Chris

braddman

So in those versions only 1 wire goes up to the actual area, then they parallel from one speaker to the other one?

latemodel21

in early models, one pair of wires goes up to the speaker area where it is then split. The wires first go to the left rear fill (behind driver) and then on to the right rear fill. If I remember correctly, it is further convoluted, by one wire going directly to the left rear (and then split out to the right rear) while the other wire goes directly to the right rear (and then split out/routed back, to the left rear).

the 2 wiring scenarios shown in the WIS document you attached are actually accurate for these speakers.

Worth mentioning, the diagrams from the Mercedes ETM are in full color and nicer to work with. .... additionally, if you have the ETM (ie access to on your computer), you can hover over most any component designator and it will tell you what it is (rather than having to go to the table).

hope that helps,
Chris

bobterry99

The factory amplifier has frequency filtering and other signal processing that a typical aftermarket amplifier will not have. I may be mistaken, but I believe there are no external crossovers on any of the speakers. If you feed the full audio frequency range to all of your speakers you will increase distortion and compromise power handling.

braddman

You're mistaken. Most aftermarket amplifiers have built in active crossovers. They do the exact same thing.

bobterry99

I took a quick glance at the perhaps the 50 most expensive amplifiers on Crutchfield. I only found one with an active crossover for a tweeter and a midrange, and it only has 4 channels of amplification. That's a problem, since 5 are needed to operate just the door speaker midranges and tweeters and the woofer.

The crossover problem can be overcome with the addition of passive electronic components to the speakers. But then you have the issue of how to operate the center speaker in the dash and the two in the rear. The factory amp applies digital signal processing to the left and right stereo channels to create two additional audio channels.

The factory amp has been engineered with filtering, signal processing, and equalization to optimize the sound from the vehicle speaker system. When you replace that amp with aftermarket you throw all of that away -- for what?

braddman

Again you're absolutely and totally wrong. Pretty much every 4 or 5 Channel amplifier on the market has an active crossover. I don't know exactly what you're looking or searching for there but that's just totally and completely wrong.

Why would you get rid of the factory sound system? Anyone into audio will tell you that the factory SL65 Soundsystem is inferior. It doesn't even have an actual Tweeter it has a 4-inch midrange. It has a tiny subwoofer design with space in mind and nothing more.

I can go on Amazon or Ebay right now and find you 50 amplifiers with active crossovers on all 5 channels or 4 channels. As a matter fact I've got about 5 I've been debating over.

As a matter of fact even in its time in 2005 this wasn't a great audio system. There were much better systems in other Mercedes


It took me 5 Seconds to find this amplifier that I've been looking out with five channels of crossover capability.

http://www.ebay.com/itm/301974115907

• Variable crossover filter (Ch 1 - 4): 40 - 500 Hz, 12 dB/octave
• Variable low-pass filter (Sub): 40 - 500 Hz, 24 or 12 dB/octave

What's that mean?

I think you're saying an active crossover for every single driver in the system? Crossing over the mid-range in the woofer separately? Again I have all this thought over so don't worry it's under control. They do make passive stand-alone crossovers if you want to get that into it. They're eighty bucks.

bobterry99

Getting rid of most or all of the original sound system is one matter, and I am sure this has been done with satsifactory results; using an aftermarket amplifier with the existing speakers without proper crossovers is completely different.

The door speakers have-1/2" and 3-1/2" drivers that I have referred to as a midrange and tweeter, respectively. A reasonable guess at the crossover frequencies would have the smaller driver operating from 2 KHz and above and the larger driver operating from 250 - 2 KHz.

Right, and nearly all of these are for crossing over from a midrange driver to a woofer or subwoofer -- they have no provision for crossing a midrange and a tweeter. For the two drivers in each door you ought to crossover at a frequency of perhaps 1 or 2 KHz.

What does that mean? It means that in your re-engineered system frequencies down to 500 Hz are probably going to be handled exclusively by those little 3-1/2" drivers in the doors! That's bad. Do you know the frequency response of these drivers? Does it extend down to 500 Hz? If they only go down to, say, 800 Hz, your new system will sound terrible. But suppose they do go to 500. Now the 3-1/2" drivers are dissipating much more power than they were originally and that is going to reduce the power handling of the overall system commensurately.

My guess is your system won't have enough channels for every driver in the system. I suppose the driver in the dash will be dead, and I can't guess what you have planned for powering the little 2-1/2" drivers in the rear.

Omitting a high-pass filter on the 6-1/2" drivers in the doors (midranges) will cause them to interact acoustically with the Acoustimass woofer in a signficant way, but my guess is it would not be of any concern. This is car audio and not hi-fi.

braddman

You're over thinking this way too much dude. I have Infinity components for the doors and they have active crossovers. So really nothing further needs to be said. Fine if you want to cross over the factory door drivers passively that solves your original problem end of story. As for the factory filtering and whatnot it's just plain crap like the factory sound system and the underpowered factory amp.The cheapest of the worst factory sound systems today perform better than this supposed high end system.

carlsturm

Thanks for the post. I'm going to attempt to tackle an issue with mine but the music in your YouTube portends this might be a serious project

reference123

Good Evening. I have a 2005 SL55 and pulled my Comand head unit today to look at a replacement. My Comand unit has a single plug in the back with two fiber optic lines and three wires, blue, brown and red/yellow. There are no other connectors. Are there only three wires that run into the device and if so, can you help in identifying? I suspect brown is ground, red/yellow are power and what is blue for?
Thanks!

latemodel21

Blue/Blk is the "wake up" signal