amgalex

Ok guys i have the stock stereo with no NAV, buying a new unit with GPS, MP3, DVD single slot stereo

I already purchased the radio after found out the output is 40w max each channel or 8 watt rmps power per channel, that is not very strong as far as i know but feel free to give me input. If I combine aftermaket radio with the stock AMP does that combine the total power output of both units?
Will factory amp sound decent with aftermarket radios or should I just replace it?

Thanks

MR888

The stock amp will not work anymore I believe, the new deck will drive the speakers, but if you decide to upgrade the speakers or add a subwoofer, then i'd suggest getting an aftermarket amp.

amgalex

As far as I know you can leave the factory amp and install pretty much any aftermarket radio but Im just wondering how is the sound quality and power output of the stock Amp.

Esh

I would just replace everything, including a new amp, but that's me.

Fabio D

You can replace the stock head & conserve the stock amp & the sound quality depend on head unit, the alpine F1 have a flawless sound quality, some pioneers sounds extreme good too, i replace one head with the pioneer 7650dvd with the stock BOSE amp + speakers & the audio quality are perfectly at all, im impressed with the sound quality when i put this stereo (not my car) but realy sounds perfect

saintz

What year is the car? That will matter in terms of your options.

The '99's use an analog connection between the headunit and amp. The 2000's appear to use a fiber optic connection between the two, meaning when you change headunits, you need to run new cabling back to the trunk and install a new amp. You can use the stock speakers and speaker wiring: just pull it from the old amp. Note that the speakers are a different resistance than most (I think it's 2 ohm) so you will have to find a compatible amp.

I might be able to give you some more pointers, depending on the year.

amgalex

its a 2000

Fabio D

I think the optic fiber wire only go for the cd changer (Head unit - CD changer interface), not go for the bose amp. please correct me if i'm wrong! but i think independent of the year of the car you will install any head (you need to replace your cd changer if you like to run the 6 cds, cause the stock cd cnanger is not compatible with aftermarket head units). the car that i install the 7650 dvd are 99 & not optic fiber.. Anyway, the optic fiber wire in the news W211 + pass for the amp. but i think the 202's & 210's optic fiber D2B not go for amp

saintz

My understanding is the 2000+ models use the DB2 fiber optics to run several things, including:

Head unit to CD changer
Head unit to amp

This means you can't just plug a new head unit into the stock system. However, I haven't personally validated this and I know there is a lot of misinformation out there. I would recommend pulling your stock stereo out (you'll need a set of radio keys, or else use a small swiss army knife). Check the wiring loom for the radio.

If there are only about three metal wires and a fiber optic wire going into the head unit, it uses fiber to communicate with the amp. If there are more like 10 metal wires and an orange fiber optic, it uses analog connections for the amp and fiber for the CD changer and phone (this is good, it means you can easily go after market).

If you're using fiber to the amp, you need to replace the amp if you replace the head unit. This isn't a huge deal, but you need to run wires from the head unit to the trunk where you need to install an amp. It's a little more complicated, since the speakers are 2 ohm.

Let me know if that helps, and if you conclusively figure how the Head unit is wired, please post.

saintz

To answer this briefly, for both fiber optic and analog amps, here is my take:

Fiber optic
On the Fiber optic system, you could basically go several ways.

No amp
You could in theory run this aftermarket headunit without an amp. You could run new wiring from the head unit to the speakers directly, or run wiring to the trunk and then patch into the stock speaker wiring (where it hits the amp, just remove the stock amp). I wouldn't recommend this. First, as you point out, the stock power of the HU is not very high. Secondly, the HU may have issues with the resistance of the stock speakers, which is non-standard. Third, the subwoofer won't work very well, since the HU undoubtedly has subwoofer pre-outs, but no amped output.

Minimal replacement
You can replace the stock amp as well. Run cabling back to the amp in the trunk and patch into the stock speaker wiring. Caveats here are getting an amp that can work with the lower resistance speakers and also making sure you close the fiber loop when you remove the stock HU. I believe this can be done with a fiber connector, but I haven't tried it. If you don't, I believe you'll have an issue with the loop being open.

Full replacement
Some people prefer to replace the stock speakers as well. You could rewire the doors, but this probably isn't entirely necessary. This option is more likely to be compatible, but will involve opening all 4 doors for new speakers.

Analog
There are two ways to wire a new analog amp. I won't call it the "right" way and the "wrong" way, but I think one is certainly optimal (the one that only amplifies once, btw).

Double amplification
The most common way to wire is to take the speaker level outputs from the radio and patch those directly to the Bose amp. This gives you the problem that the HU is putting out speaker (high) level and the Bose amp is looking for line/pre-out (low) level. In short, at quarter volume on the HU, the amp will be over driven, so you basically can now only use a quarter of the volume dial on your HU. The best option to solve this is an adapter that basically cuts down the signal so it's closer to what the Bose amp is expecting. You still have a problem, however, that you're amplifying the signal at the HU, cutting it down, and then reamplifying it. There will be a quality loss with double amplification, but this method will work with any HU.

Single amplification
The best option is to pick a HU that uses 4v or higher pre-outs (Pioneer and Kenwood make inexpensive models). These can be wired directly to the Bose amp without needing double amplification. You may want to use an adapter, not to electrically change the signal, but just to adapt from the RCA pre-outs on the HU to the pigtail/bare wires you'll be using for the Bose amp. This is how I wired my 1999 CLK, and the sound was great.

I hope that helps.

amgalex

thanks a lot!
lots of helpful info

Peter_02AMG

I can confirm that only fiber optic is the interface between the CD changer in the trunk and the head unit. ppls keep talking about fiber optic

saintz

Peter, just to clarify, you are saying that the connection from the stock HU to the amp is analog in your 2002 E55?

I have been meaning to verify mine with my own eyes, because I agree about the "rumor" problem. I have been unable to pull my COMAND unit out, however, even with keys, so I couldn't verify yet.

If the system is in fact analog to the amp (not worried about the fiber optic CD changer, an iPod is way better anyway), this is much easier. The only challenge now is steering wheel integration, which seems to have several options.

Peter_02AMG

Yes, only fiber optic is the interface between the HU and the CD changer. The blue wire tap into the harness is the audio mute wire for my Blinder Laser jammer
Our car is not that advance.

saintz

Thank you Peter, that is very, very helpful. I had a feeling, but I like I said, I haven't been able to verify my own car. Any idea why a COMAND system would be stuck?

It appears these should be analog. You can just splice right in. Only downside is you need to buy a steering wheel controller, if you want it. Not a huge deal.

Peter_02AMG

You can keep the stering wheel function if you use the ALPINE-KCE-868B to interface with the stering. volume +/- , seek/scan, Ipod up/down.

http://caraudiosecurity.com/shop/pro...ts_id/461.html

You will also need a Metra #70-1784 "Volkswagon" wire harness and the PAC OEA-2 to turn down the gain of the stock amp down and a PAC TR7 Video bypass if you want to watch DVD while car is moving

Hope this help you guys out.

ProjectC55

I concur 100% the only thing using fiber optic cable in my C43 is the CD changer. All I need to do is swap my head unit out. I only need to see if Crutchfield or Radio Shack has a wire to radio adapter.

I already have an Infinity powered subwoofer in the back being conrolled by the factory head unit volume,fader,bass and treble wise, and I got rid of those lil old rear Bose speakers. The front speakers are the only speakers I have connected to the factory amp. System in my Benz sounds darn good despite the fact that I have poor AM radio reception. I hope that problem would clear up with a nice new head unit.

Fabio D

Thanks pete! i like your AMG badge location. nice

amgalex

ok guys finally got my stereo so I took stock unit out and noticed a fiber optic plug in with two fiber optic wires, on it a tag says "amp"
So amp in controlled by this fiber optic plug in?
I ran into a few problems; first there is no ignition +12 only constant +12v wire
I checked all wires with a volt meter in my attempt to find it, no luck.
found out later from researching that 2000+ models don't have an ignition wire, but thats an easy fix by tapping into a cigarette lighter ignition wire solves that.
second after connecting speakers and turning on the stereo , there is no sound coming from speakers, amp must need a signal to turn on or who knows. Anyone know how to make amp to turn on or am I missing something else here?
Thanks

Fabio D

Yaa, you need the remote signal to start the amp! you need to plug the blue wire of your new head unit to the blue wire in the amp (Remote circuit).. them start the amp

amgalex

ok I got that to work, radio works so after all only CD changer uses fiber optic cable.

I ended up running the radio from RCA outputs, that sounds the best. For some reason there is hissing sound when speakers connected directly not through RCA's.

Also I took a look at the AMP and how it is wired. Looks like a very easy wiring diagram; 8 wires for inputs of speakers 8 outputs, remote +12, Battery +12 and Negative. noting extra here so if someone wants to change to aftermarket amp it would be easy to do or just connect inputs with outputs for direct head unit to speakers play.

saintz

+1, you definitely wired it the best way, as you noted.

I've seen so much stuff about "the amp uses fiber," "the amp gets a wake up signal over fiber," etc. It's great to see it's all misunderstanding and that it's easy to wire this up. Thanks for posting back your results.