1998 E320 audio

Can anyone give me some ideas for improving the factory sound system in my 1998 E320? The rear speakers boom too much and on the front ones the bass actually rattles the door (you can feel it in the arm rest) but you can't hear it!

I also have a few basic questions:
1. What brand is the sound system? Becker? Alpine? (I have the regular radio and a trunk mounted CD player.)
2. What size speakers are used and where are they? (I know that sounds silly but it's not obvious what's behind each grill!)
3. How do I get the grills off without damage to take a look?
4. Whats the best way to access the speakers? (in case I want to change them.)

BTW, as a hobbyist and electrical engineer I am quite expert in regular sound systems but I am somewhat inexperienced in car audio (it seems to have its own rules!) - However, I would like to remedy my lack of knowledge.

All help gratefully received.

Cheers,

[Mattk]

I am going to assme that you have a Bose system in your car.

If not, the speaker sizes should be the same, the amp may be different. This is the set-up my car had:

I took care of all rattles by applying a product called dynamat to all metal surfaces in the trunk and in the doors. It is a sort of self-stick asphalt mat that dampens vibrations and generally makes the car more quiet, which is saying a lot for an already very quiet car.

90% chance that your head unit is a Becker, 10% chance it is Alpine.

Amp is made by Bose (peice of crap)

Speakers are made for Bose by Nokia. They are really cheap paper speakers that do not reproduce sound very accurately.

Front doors: 6 1/2 " with 1/2" tweeter in a grill over the woofer. Both are enclosed in a plastic speaker housing that is accessed by removing your door panel There are three large screws (behind SRS badge, behind round cover under arm rest and under plastic trim peice behind the door handle) take all out, pull the door off from the bottom, then lift up. It will resist but will come off.

Back doors, 5 1/4" full range speakers. Find the screws in similar places as front doors

Rear Deck holds two 7" Bose "sub-woofers" that only reproduce mid-bass which is why you get boomyness.

I disconnected everything bose and replaced with aftermarket. You can see what I did by going to this web page, cut and paste it on your browser:

http://www.sounddomain.com/member_pages/view_page.pl?SID=GAT80WMMLE4rRQsyQg__&page_id=133487&make_type_query=make=Mercedes-Benz&model_brand_query=model=all_models&tree=Mercedes-Benz%20(all%20models)

Email me if you need any questions answered.

Good Luck

Many thanks, Mattk. I visited your website - very impresssive, both the site and the audio mods.

A couple of Q's:

In your opinion, is it possible to turn the whole trunk into a decent bass enclosure (not necesarily just a sub-woofer) by simply changing the rear speakers for large magnet, roll-surround, polypropalene coned, low free-air resonance types and adding sound absorbing and/or anti-panel-resonance material, thus avoiding having to build the separate sub-enclosure? In regular audio (my speciality), if you have a full-range, floor standing speaker you don't need a subwoofer.

Also, I presume I could get a decent improvement by replacing the cheap paper speakers in the doors with similar quality units to the above with tweeters and X-over (separate or coaxial.)

BTW, is it easy to get the door panels off?

I would leave the electronics as is for now. I fear I do not have the time for your size of project!

Cheers,

[Mattk]

Thanks, it is almost there.

Yes, you can do just as you are suggesting. It is called free air or infinite baffle sub-woofers and you may want to check out the JL audio IB4 8" which should drop right in your factory locations beautifully. BTW, you have four holes so you will have to use two or four speakers because they are 8 ohm single voice coil. Two drivers will give you a 4 ohm load and you can run a 150-200w RMS mono amp on those. If you choose to use four drivers, you will get a 2 ohm load and can use a 300-400w RMS mono amp.

http://www.jlaudio.com/subwoofers/pdfs/8-12IB4_BDS.pdf

If I did not build an enclosure, I would have gone the four driver route. It is my understanding that in an infinite baffle application, the bass is not as tight and accurate.

I would suggest buying component speakers for your front doors. You have two factory choices for your seperate tweeters. The a-pillar or the dash. Mine are in the a-pillar right now, but I want to move them nearer my mid-bass in the factory door location. If you know home audio, you know about imaging.

Coax speakers tend to have lower quality tweeters and a high pass filter as opposed to a true cross-over network. They would be fine for the back doors.

If you change speakers, you will have to change at least the amp. The Bose P.O.S. will not drive aftermarket speakers. It is intended only for the Bose speakers.

You can keep your head unit as I did but will need a high level converter or high level inputs on your amp. I thought this was a good idea but have changed my mind. The sound quality of the Becker head unit is dismal. I am trying to decide what type of aftermarket head unit to buy. I am leaning toward the Nakamichi CD-45z because it looks quite good with the Mercedes dashboard as it is available with amber illumination by special order. http://www.nakamichi.com

Door panels are easy to take off once you understand that you will have to apply some pressure to get the job done. I was reluctant at first but after a pulled hard enough, it worked fine.

Changing the speakers, HU and running new wires can be accomplished in a day. Everything is well put together and easy to take apart. Building the Sub enclosure takes more time. I am not sure about removing the rear deck to get to the sub-woofer speakers but if you ask your dealer how it is done, they should be willing to show you the directions on how to do it the right way.

Good luck

As discussed, I want to replace the factory speakers in my E320 with better units. My first move was to try and inspect what was there - but I just can't get in!

From the inside the trunk, looking up, you can see 4 holes in the back shelf body panel. Two of the holes (the outer ones) have speakers in them and the other two are just covered by foam rubber sheet (part of a molding). The speakers are in plastic mounts that clip into the metal body panel but this is separate from the shelf cover on the top. A molded rubber foam seems to complete the sandwich, i.e. (bottom, trunk side) metal panel with the 4 large holes, 2 plastic speaker holders, rubber foam, (top, car interior side) shelf cover with fabric interior finish.

I am stuck trying to take this stuff apart without damage (as I want to put it back as-is while I figure out the optimal speaker changes.) How do I get the top, interior shelf cover off? I can find no external fasteners and the plastic fasteners you can see in the trunk on the speaker plastic mounts are quite independent of the shelf cover. Or, generally, how to I get at these speakers to replace them? And, of course, how do I get it back together undamaged? (Oh, I know this one: "replace by reversing this procedure". Right!)

Any assistance (from Mattk or others) gratefully received.

Thanks,

Roger

PS: "It wasn't until late in life that I discovered how easy it is to say 'I don't know'." W. Somerset Maugham.

[Mattk]

Roger,

I di not remover the factory speakers that are in my rear deck so I really don't know the details of how to get it apart.

You will have to take out the rear seat and take off the rear deck trim to get to those speakers from the inside of the car.

Here's what I would do. Go to your local MB dealer and talk to the techs. They will tell you how to do it the right way. Mine were very helpful when I was working on my car.

If you want to try yourself. Pull up the rear seat bottom. There are two latches in the front corners. Then take off the seat back. There are two or three screws at the bottom. You are on your own from there.

Sorry I don't know more.
Good luck

[apb]

In replacing your front speakers, did you use the 'container' from the original midwoofer or did you use something else?
I took on a much less ambitious project than you and installed a Nakamichi amp (2x50) and Polk dx3065 with a Peripheral line converter. I think I will probably also add an equalizer.

I just dropped my mid speaker in the original box but I don't know if that is a good idea (it is restricted in the back and don't know if that should just be cut out). What did you do?

[Mattk]

The instructions I posted on Sounddomain should answer your questions. I used the original BOSE speaker pods. My Focal mid-bass drivers fit perfectly. I originally put the cover trim ring back on then removed it after listening. I did this because it sounded like the speaker cone was hitting the front trim. As far as the rear clearance, there is maybe a couple of millimeters but it is vented and sounds great. Really tight mid-bass with no distortion at very high levels.

http://www.sounddomain.com/member_pages/view_page.pl?page_id=133487&page=4

As far as your ideas on line-drivers, eqs etc? what are you going to use for a head unit.

I originally intended to use my factory head unit. When I added amps and speakers the sound definitely improved. I soon chose to change my head unit to a high end Nakamichi with 4V line level outputs. The sound improved VERY dramatically! I cannot accurately describe how high the sound quality is. It is dead silent (no-hiss) and very dynamic. I cannot recommend a new head unit, quality amps, and speakers MORE strongly.

[apb]

Well, I am still trying to live with the original head unit at this time and see if I like the end result.
Nakamichi sure is tempting though . . .
I am just trying to see how best to make the OE unit work first.
Do you know if a Nakamichi tape unit could be made to work with the MB CD changer?

[Mattk]

Won't work.

MB changer is probably Alpine.

I also had a changer with my MB head unit. Again, cannot describe how much the sound quality changed. Like going from a $100 boom box to a $5000 home stereo. The Becker manufactured unit puts out very distorted sound. I had it analyzed with a O-Scope because with my converter, I could never get clean sound. Thought it was the converter and found it was a crappy head unit. I drive a Mercedes, I shouldn't have to listen to Toyota quality sound. Best $350 I spent.

[apb]

Fair enough, last question.

Nakamichi CD-45z or CD-40z? Big price difference, both 4 volts, and I don't care about a remote.

[Mattk]

Two advantges to the 45z
20 bit DACs - very good quality sound - this is worth $100 alone
Changer control

40z does not have them.

[Mattk]

I really like the way it turned out. Looked a little at Eclipse but the simplicity of Nak matched the interior of the Benz a little better.

The main thing I would like to change about my install is the carpet color. I wasn't able to get something closer to the stock appearance. I will keep searching and may change it out for a better look. Best thing is that nothing gets in the way of my lifestyle (golf clubs in the trunk)

The sound is really great and I couldn't be happier.

[apb]

In answer to earlier questions about the rear deck.
I removed the rear deck to install 2 freeair Kicker F8c - it is not easy.
Here are the steps:
1) remove the rear seat back
2) remove the rear headrest. first pull the headrests up, then remove the little plastic cover at the base of the headrests, then push the little black tabs to release the headrests and pull them out.
3) remove the central brake light assembly. It slides out after the tab at the bottom is pushed.
4) remove left and right c pillar covers -fairly straight forward.
5) lift up and lide out the rear deck.
6) pull out the large foam pad under the deck.

7) Now you have a mess, are 2 hours into the project and wished you never started.

the 8" subs sort of drop in but not really. You have to drill into the deck (eating some metal dust in the process) to fasten them down. THis may be of help to somebody else.