When I power my radio on in my 92 400SE it begins making a cracking noise and the sound will jump to various speakers before quiting. I was told by the service rep this is a problem with the BOSE 7 channel amp in the trunk. Has anyone else had similar problems? I was given an estimate of $1000 to replace the amp. I was also told this was a known problem with this model and the sound system.

Anyone have an suggestions or alternatives? I 'm not really wanting to spend $1000 on a radio amp, but I want sound in my car.

Thanks,
Russell

 

Get an aftermarket one if you don't need all the MB stuffs. I am giving up my Bose for a D2P ready one for the Nokia phone if it works. Have to wait and see. I don't want to spend all the money on upgrading the phone with a MB's brand.

 

this is a very good question b/c mine is doing the same, what aftermarket amp will work on 300SE / 400SE W140's ? Rockford fosgate or would it have to be higher end.


also what about headunit, how can I put an aftermarket head unit in the bose system? i heard its really hard, but then again i heard it was easy with some small adapter, does ANYBODY know?

 

I had the same problem in my 1992 500SEL. I replaced it with a Pioneer DEH-P8400MP Head Unit and a Jensen 4 channel amp running all the stock Bose Speakers. Basically, you can put any Head Unit you want, as long as it fits and power all the Bose speakers with a highpower 4 channel amp. Any competent car audio specialist can install it. You don't need an adapter. Everything can be wired in the trunk (speakers and amps) were the Bose Amp is located. I watched the installer do it. Takes about an hour to hour and a half. Probably even easier and DIY if you can find an adapter. Now I can play mp3s in my headunit and store about 10 cds on one mp3 disc. No need for 10 disc changer.

 

Thats the exact reason why i wanna know b/c I already have a JVC SH99 MP3 CD player and I want to keep it so i think that would be perfect. how many watt is the bose amp? b/c i wanna get something better. I never knew it was that easy to convert, i thought there was an amp at ever speaker making a total of 13 (extra main amp) at least thats what i thought. how much was that 4 channel amp you bought and what was the wattage? how did it sound, same? better? or not as good? thanks for input

 

The failure is a common one, Becker will rebuild it for $400w/ warranty, go to their wep page. The amp is located above the rear wheel next to the gas tank. Both the gas tank liner and wheel housing liner should come out, they are easy to remove. The door closing assist pump is in there also, but that is a project for another day when it fails. There are also authorized rebuilders, make shure you get a warranty, on E-bay could could end up with a bad one.

 

I'd highly recommend gutting the entire system if you can, or just have the amp rebuilt if you don't want new stuff, but wheres the fun in that? If you want to replace the head unit, do everything. We're talking about speakers that are 10, 11 years old here, very good in their day, but you can definately do better. Go with something higher end than a fosgate amp. Fosgate is actually a rip off all things considered, get Zapco and be happy. The amp is the single most important piece of the system, I don't care what others say, you can't have a good system with bad amplification. You can make crappy speakers sound decent with a good amp, and high end speakers shine with the same. Its like using regular unleaded in your Benz, you only get so much out of it. But you WILL need an amp for these cars since they have so many speakers. I used to work in a couple nice audio stores, so if you need any pointers or anything, let me know.

 

ok guys, tell me what u think about this setup

--JVC MP3 CD player (i already own this and i'm swapping it from my M3, best headunit i've ever seen/heard)

-- 1500 watt rockford fosgate 4 Channel amp (i'm getting it for free so price not an issue).

is that enough to power the whole sound system? let me know. thanks guys

 

You're using the stock bose speakers?! Eh, with one four channel amp, you're going to have a real fun job wiring, so I would recommend getting another 4 channel amp to run with it. You could use the RF to power one high power sub (kicker solo baric L7 for example, or any other good sub that can handle 800w), or two decent subs off of two of the channels, and then use the other 2 channels for the 4 mid bass on the rear deck lid. Definately replace all the speakers though. If you want, email me and I'll tell you exactly how to do it and what I'd recommend getting, but you'll need another 4 channel amp for sure, but the sound you'll get will be outstanding. If you think that JVC has good sound quality, you should hear an Eclipse or Alpine.

 

that makes no sense why would i need two four channel amps? one 4 channel should do the job. 1 channel for each corner of the car. I think JVC is much much better looking than the eclipse and alpine, I listened to alpine and JVC sounded alot better in my opinion, this specific unit i have sounds AMAZING. anyways please explain why i need two 4 channels that just does not make sense

 

You need two four channels for ease of wiring. You have 12 speakers in that car, and to wire 3 per channel is a pain in the ***. Think about the ohm load and parallel/series configuration you'd have to do to make that work with enough power. This is all assuming you're running aftermarket speakers in component sets. The way you're thinking about doing it would require you to run the front tweeters off of the deck power, and then the front door speakers off the amp in series to up the ohms so you don't blow them up, and then run the rear door speakers in series, two of the rear mid bass drivers in series and then run those two with one door together in parallel, and the same for the other side. Not really a fun job and you get an interesting misbalance of power to the speakers . If you had two four channels or even one four and one two channel, you can run each door to its own channel off the 4ch amp, and then run the rear deck ones off of another 4ch with a sub or subs off of the remaining two channels, or just run those rear speakers to a 2ch amp and then you get a nice balance and proper fade and balance control from your deck, assuming it has 3 sets of pre-outs. Thats the ideal way to go. What do you think? Any thoughts?

 

that does not sound right sorry, I was told that i could run the whole system with even a single two channel amp, but i opted not to. I want to run everything off this 4 channel amp, the amp can push it, its a 1500watt amp. that just does not sound correct at all to me. i've never heard anybody doing that nor does it seem logical.

 

LOL... A 2 channel amp!!! Honestly, not to be mean, but think about it. 12 speakers...2 channels... If you don't think my explanations are logical, just go to your nearest car audio place like Car Toys or whatever, and talk to ANYONE working there. Tell them you have a mercedes with a 12 speaker system and you want to run it off of a single 4 channel amp with lots of power. As I had said, you can do it, its just a huge pain in the ***. Then ask them about running it off a 2 channel amp, and watch them laugh. I'd really like to know who told you that you can run 12 speakers off of a 2ch amp. Thats just funny. But why does my logic seem incorrect to you? In a normal stereo, you have a channel for each speaker, thats just how you do it unless you want to run more and you're not going to do any different balancing on those, or you have a component set with its own crossover. Don't disregard my input, 'cause you're talking to a professional giving his professional advice. Go ahead and run the 4ch amp to 12 speakers, but have someone else wire it up for you, at a stereo shop, 'cause its not something you'd wanna do, and you may or may not know how to tackle something like that, I don't know. Call up a stereo shop and then let me know what they say about all that. Don't take this the wrong way though, I appreciate your interest in the cars and what you're doing for and with them, I'm just giving you honest advice about the stereo, no hard feelings bud!

 

im not taking hard feelings i just don't think thats the logical solutions, im a firm believer in KISS (keep it simple silly) and multiple amps just seems too complicated.

I guess i can just get another bose amp and not have to worry about all the hassle and then just run my aftermarket head unit. would u run the RCA outs or the regular output though?

 

OmeyHomey,

No offense, buddy, but you don’t know what you’re talking about here. I have to agree with Dual 5Ls on everything he said.

First, a little background on Bose automotive systems. These systems are built to work as a whole meaning that the speakers’ crossovers are built-in the amp and the signal from the deck matches the amp’s inputs. Basically, the only options to upgrade Bose systems are to either gut the entire system, as Dual 5Ls mentioned, or do nothing at all. One can change the deck and/or the speakers and/or the amp but he/she will NOT get optimum sound quality. I’ve tried every possible combination to get better sound from Bose and it’s just impossible. Of course, I’m talking as an audiophile so the average user probably would not tell the difference between a full Bose system and an altered one. In fact, I know many people with altered Bose systems who are happy but remember, once the system is changed in anyway there is no more balance in sound quality. It boils down to whether or not one is perceptible enough to hear the difference.

Anyway, about the Bose system in the W140, the amp is a 7-channel, I believe. OmeyHomey, think about it. Why would you replace a 7-channel amp with a 4-channel and expect BETTER sound quality? First, remember that the speakers’ crossovers are built-in the amp so if you replace it, the signal won’t match the speakers resulting it crappy or decent sound ONLY AT CERTAIN VOLUMES. I’ll try not to be too harsh about the 2-channel but it’s the most ridiculous idea! 12 speakers powered by a 2-channel? On many amps, one channel per speaker is barely enough so how can one channel do 6 speakers? Also, you seem to be fond of your Rockford Fosgate “1500” watt amp. I hate to burst your bubble but Fosgate is crap and that 1500 watts you’re talking about is most probably MAX output at 14 Volts. Your battery only gives out 12 Volts and max output is dirty power resulting in crappy sound. On amps, focus on RMS watts at 12 Volts. You’ll notice that on expensive amps they only claim about 75 watts X 4 channel. It definitely seems less than the “1500 watts” but, in actuality, it’s cleaner and more efficient. Oh, and you mentioned “one channel for every corner of the car.” You’re forgetting impedance. It’s not that easy! Going on to brands now, I’m sorry to say that JVC is actually among the cheapest quality brands. You will NEVER see a JVC head unit at a competition. Eclipse and Alpine on the other hand are well respected names with excellent sound quality.

So to sum it all up, OmeyHomey, your JVC deck and Fosgate amp will work in your car but you won’t get optimum sound quality. Psychologically, you may (since you’re replacing stock equipment with aftermarket) but if you were to do a double blind test it could prove otherwise. I’ve been into car audio for a long time and have played with MANY Audis and Mercedes (Bose systems) and this is what I came to conclude. However, don’t take my word for it. Do what you want, it’s your car. Just remember to keep us posted.

Sidd

 

the reason i want to use fosgate is b/c im getting it for free and I already own my JVC head unit.

About head unit, stock one is garbage, tape deck... EEKKGKHGG .. gross. My JVC is MP3 CD player so it is a must. I researched and listened to EVERY MP3 CD player on the market and JVC was best by far, the rest were ****ty, low in quality, or just plain but ugly.


About the amp I did not know bose was 7 channel, Is there anyplace i can get a cheap bose amp new? i heard one place had them for $400 plus warranty, there was a post about it, do you know who posted that?

aftermarket head unit should sound ALOT better than stock unit i have no idea why u are saying that it shouldn't. plus there is very little flexibility in sound from the stock headunit theres 1 treble and 1 bass button, thats it, plus i hate tape deck.

MP3 cd player is MUST, it changed the way i listen to music period so i must have it (even if you claim it will "hurty" sound quality).

anyways let me know, thanks for the help.

 

Hey Homey,
Sidd is right about the amp stuff, but I thought it was 7 amps at 240w (total power) max? VERY efficient system! The wattage I'm certain of, as it says in my bose manual. Its either 7ch or 7 amps, but I've heard one of both side, but either way its at least 7 channels. I'm surprised you didn't like the alpine mp3 player. The model 9811 I believe is a damn good deck and supports MP3s. You may or may not find a useability plus from the JVC deck, but I know the Pioneer MP3 decks suck for playing them.
The $400 Bose thing you saw was a price for rebuilding an existing bose amp. Keep in mind you can't wire an aftermarket deck into a Bose amp, it just doesn't work like that. Proprietary stuff here :-/.
You are right about running multiple amps and it getting complex, but its less work than doing a series-parallel jew-rig job, and you'll get FAR better results that way. Another option is to sell the RF amp for what you can get and buy a couple nice amps like the Zapco stuff. What it really comes down to is money. I quoted a friend of mine a system for his '93 SL and I came out to $8000 for top of the line, and I was using Zapco. You can get away with running Coustic or Planet Audio to save some money. Both of them are great amps and a good value. I believe the guys from Pheonix Gold make Coustic now, and I've heard them and can't complain too much, but you'll never beat Zapco, those are amazing.
It really sounds like you just want to use what you have though, but I'd at least replace the Bose speakers. After listening to mine today at volume, you just don't get enough tweeter out of them, and the bass does distort a little when it gets demanding. For an 11 year old system, it sounds great, but no where near what is available today. Any questions about speaks or anything else, just ask man.

 

i do not see why i cannot just use my JVC head unit with the stock system. they make the stereo harnesses for the W140 S-class and everything. if it doesn't work they why would they make those wiring harnesse to adapt to aftermarket head units, makes no sense. thanks for help again guys, seems like you two are the only ones that really know anything at all about the bose system.

 

OmeyHomey,

The reason why the stock Bose deck sounds better than aftermarket decks IN THIS CASE is because, again, Bose systems are built to sound best together. Don't let that deck fool you, inside is circuitry that's far more advanced than even the most expensive aftermarket decks out there FOR THE BOSE AMP ONLY. The deck has a built-in EQ that's set to work in harmony with the amp which has the built-in crossovers with the perfect setting for optimum sound quality from the speakers and also protection so they don't blow up. The treble and bass knobs are actually all one needs in a system. In fact, in my system, I don't use any EQ or tweak the bass and treble. I'm a purist and like my music to sound as it was recorded. You're correct, they make harness kits for aftermarket decks so it is possible to use any head unit but, again, you lose musical balance. Personally, I can't take the degradation in sound quality so I don't recommend it. However, most people change decks for the same reason you are, they need a CD/MP3 player and the loss of sound quality is a trade-off they're willing to accept. If you change your head unit AND amp, you're off to a good start since you won't have any signal mismatch there. HOWEVER, your stock Bose speakers won't have the correct crossover settings resulting in poorer sound quality AND the risk of damage. I'm not sure if you know what I mean by crossovers but the wrong crossover settings can damage speakers. Bose speakers don't go below 63 Hz and if you send a full signal through your amp, you'll blow them. Now if you crossover at say 80 Hz you obviously won't blow your speakers but you'll have lack of bass. Crossover settings are important. What I recommend with your equipment is to buy a pair of quality components and have them placed in kick panels. The imaging will be MUCH better and sound quality top notch since the speakers come with their own crossovers. Oh and you'd need a sub, too. The best system I've installed in a W140 consisted of 2 pairs of MB Quart components (kick panels in front) and 2 subs in the back. The head unit was an 8 Volt Eclipse with matching amps (2 of them). The sound was perfect and everything was about $4000. In your case though, I'd shell out a little more money on some speakers. You don't have to get expensive ones because I guarantee that any brand correctly amplified sound better than the stock Bose. If you only change the head unit and amp, you'll notice poorer sound quality. If you're going that route, I'd only recommend changing the deck since you need the built-in crossovers in the stock amp to get the most out of the stock speakers.

Wow, lots of information. Anything else, just ask. Dual 5Ls, please feel free to agree/disagree with me. I love coming across fresh new ideas.

Sidd

 

again thanks for the info...


I think I will just go the JVC head unit with bose amp. I did not realize the bose system was THAT complex. I am willing to sacrifice alittle sound quality drop for MP3 playback (its DEFINATELY worth it). haveing 150-200 songs per CD is a big bonus. I think the quality drop should not be too bad b/c I will be playing CD versus tape or radio which is not nearly as good sound quality as CD so maybe the two will offset each other

DO you have have the contact info for the place that rebuilds bose amps for $400 plus warranty? if so could you tell me. thanks and have a nice day

 

Think of it this way, the amp and speakers are one component so change either one and you have to change the other (for optimum sound that is). I'm a firm believer of "all or nothing" in Bose systems but I guess changing only the deck is OK. Here's the site of the company that rebuilds/repairs stock Bose amps

http://www.beckerelectronics.com/stereo.htm

Let us know how everything turns out.

Sidd

 

Hey Sidd,
Yeah I do agree with you as well on everything you've said. Glad to see that you too agree with my 'all or nothing' philosophy. I would differ in opinion for speaker placement, but not disagree. Kick panels as we know are a good option for adding speakers, but since the woofer and mid are close enough together already in the doors, you could place the tweeter there too instead of a kick panel for more of a stock look, and I think you might get a little better imaging out of it too. The cool thing about the kick panels is that you assemble them with your component set and you have proper imaging, in that spot, and you're good to go. I'd rather put the whole thing in the door in stock location, for a stealth look, and also the sound would be a little closer to your ear and treble should be clearer. I only say that because the tweet wouldn't be blocked by the dash and underhang it has. The firing of the woofer in the kick panel would be better, but bass is bass, you hear it wherever you put it. Also a kick won't give you the option for running a 3 way set. I just don't like speakers at my feet where I can ram my foot through them . Bottom line, both door location with relocated tweeter and kick panel options are good, I prefer the door.
Sidd, you obviously know what you're doing if you ran an Eclipse head unit! A lot of guys will poo poo them because they're not on commission or because they think Alpine is better, its not. Alpine runs 4v, Eclipse now has 16. Eclipse's entire mission is to beat Alpine in everything they do, and they're doing a good job at everything, except marketting. They make GREAT stuff. If you want a killer sub, go to adireaudio.com and look at the Brahma series subwoofers . Amazing, and the best sub I've ever heard. A near flat BL curve and somewhere around 27mm XMax. Dan Wiggins, the owner, is a friend of mine so he showed me the subs in action and its the sub I run in my porsche (the 10").
I run that and Peerless drivers in my doors with an Eclipse 7002 lcd head unit. Zapco Studio 150 for the sub and Studio 204 for the components are to be next. The mercedes is completely stock, except for a planet audio amp running a couple subs in the trunk for temp usage. Pretty neat being able to add a complete sub setup without having to tear up any carpet, or run any wires outside of the trunk .
So Homey, let us know how it goes!

 

You're right, door mounting is best for the stock look but how would you angle the driver side speakers correctly so that they aim at the passenger and vice versa? That's the reason I like kick panels, you can angle them however you want to get that sweet spot in the middle. Plus it's hard to custom fit speakers on the doors. Also, where exactly do you put the tweeters? I agree with you, though, tweeters should be at ear level.

Anyway, what are your plans for your S500? I checked out that sub you mentioned and the magnet is HUGE! I'll have to check those out. Let us know when you start the system in your Mercedes.

Sidd

 

If your main concern for your car is being able to play MP3's, then why not get the Alpine 6-disc changer that is available. I saw some threads on this topic, but can't recall what site it was on, possibly this one, I'll do a search. As you probably know, the stock 6-disc changer in the trunck is made by Alpine and is controled through the existing stock head unit. However, there is a newer version of this Alpine changer that plays both CDs and MP3s. I can't recall the model number, but I think there are some additional adapters needed to make it work. According to the thread that I read, everything is functional through the stock head unit.

 

Here is the link for the thread discussing the Alpine changer.

Some of the posts in this thread are very informative. Do any of you have any insight as to if this changer will work properly? Do the required adapters distort sound quality?


W140 CD Changer Thread