Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help

Go Back   PeachParts Mercedes-Benz Forum > Mercedes-Benz Tech Information and Support > Car Audio and Multimedia

LinkBack Thread Tools Display Modes
Old 10-17-2005, 01:32 AM
James24V's Avatar
Registered User
Join Date: Feb 2005
Location: Melbourne, Australia
Posts: 10
Example of 5.25" speakers in a W124 dash & 5x7"s in the rear...

Hi Guys,

A lot of people wonder if they can fit 5.25" speakers in the front dash of their W124, especially those without door speaker panels like myself. Rainbows are obviously the only "drop in" replacement, 4" speakers donít fit properly, and you really need some kind of bracket because the hole is slightly larger than 4". Similarly, people usually only put 5.25" speakers in the rear unless they go for the chop under the headrests or medkit. I wanted the best sound I could get from these locations keeping the look totally stealth, ie grilles fitting over the speakers perfectly so no one would have a clue what you have under there.

Front Dash Speakers

I used Infinity Kappa 52.7i's for this location. These have a compact neodymium magnet that makes for big power plus easier fitting inside the dash. Other 5.25"s will fit, I tried some "chinese" ones successfully too, the smaller the speakers cut out is the better. For the chinese speakers the cut out diameter was small enough that the only cutting I needed to do to the dash I could do with box cutters! With the Infinitys it was a little more difficult so I used a Dremel tool. A lot of people are worried about cutting up their nice Mercedes, so was I but if you are careful and just cut the diameter out a tiny bit at a time there is nothing to worry about. Plus these speakers are going to stay with this car for the rest of its life, and any cutting I did is hidden under the grille.

mmm.... stealthy

Rear Speaker

I was quite baffled as to what to do with the rear speakers; the options seem limitless if you are going to cut thru the medkit. I decided I still wanted to keep the install stealth and try install some decent speakers under the oem grilles. This would also leave room for porting a subwoofer through the medkit if I ever got around to that (which I doubt I ever will now). 5.25"s do not fit perfectly into the brackets that the oem's sat in so I felt that I would have to make my own bracket. Whilst doing this I wondered if 5x7"s could fit with my own bracket, yes they could I decided. I chose Polk EX357s. The reason for these is that they are truly 5 inches by 7 inches and not verging on 6x8s like Infinitys and other higher end brands. 6x8s would not fit.

I made a bracket out of MDF using predominately a jigsaw and a file. It was a bit of trial and error to get it to sit properly onto the uneven steel rear deck as you can see.

I got there in the end but also had to cut a small bit out of the original speaker hole for the magnet to fit in. Because of the 5x7s elongated shape the magnet sat too far back to fit nicely in the original hole, I used the jigsaw for this.

Further, the speaker grille sat nicely over the top and the rubber rollover edge of the speaker cleared the shelf.


I run all 4 speakers at half gain on my 4x80WRMS amplifier that I have riveted under the parcel shelf. Of course if I was to buy a subwoofer this would be pulled down from there.


All in all the system is unreal. The bass response is very strong and clear although you do need to turn it up a bit to get the strong bass, this is the trade-off of having higher-end speakers. The bass is slightly stronger from the Polks in the rear, they are rated 10Hz lower than the Infinitys but I am guessing the "box" that is made with the trunk may help in this regard compared to the cramped "box" under the dash of the Infinitys. I run it off an old Alpine stereo (takes some of the stealthiness away I know), I would love a new Becker system though. The mids and top end are perfect and with the windows down you can hear lyrics from songs clearly over 50 meters away. As expected you don't get the same from the bass but in the car the bass is more than enough, hence why I will probably never get around to installing a subwoofer, I simply don't need it now, not for my listening pleasure.

Cheers with your install guys, hope this gave you some ideas and guidance.
1990 Mercedes-Benz 300E-24
Reply With Quote
Old 10-18-2005, 02:21 AM
Registered User
Join Date: May 1999
Location: Sacramento, CA
Posts: 1,472
Thanks for reposting, that was a good article. It might be worth it to post it in the DIY wiki up at the top of page too.
2000 C 2 3 0 Sport :: 180k
Reply With Quote
Old 10-21-2005, 08:29 AM
Registered User
Join Date: Dec 2003
Location: new jersey
Posts: 181
what about the impedance? I read in the shop manual that merecedes stock speakers, besides being odd sizes are 2 ohm (like bose i believe). aren't infinity & polk's 4ohm?
***just checked my specs. on stock system the woofers are 2 ohm. the dash and rear deck are 4 ohm.

Last edited by tan man; 10-21-2005 at 09:12 PM. Reason: correct info
Reply With Quote
Old 10-21-2005, 09:49 PM
James24V's Avatar
Registered User
Join Date: Feb 2005
Location: Melbourne, Australia
Posts: 10
Originally Posted by tan man
what about the impedance? I read in the shop manual that merecedes stock speakers, besides being odd sizes are 2 ohm (like bose i believe). aren't infinity & polk's 4ohm?
***just checked my specs. on stock system the woofers are 2 ohm. the dash and rear deck are 4 ohm.
Impedance is not a problem when you re-do your entire system. The OEM speakers in mine were all 6ohm running off the Becker unit through the fader. Once you scrap that idea you can run whatever ohmridge you like as long as your hardware is all compatible. My Polk speakers are 4ohm and my Infinitys are actually 2ohm, I am running them off an amplifier which is both 4 and 2 ohm stable so there is no issue at all.

This might be a different story if you tried to put these new speakers onto the OEM headunit. Also I'm sure you could make up a good combination using the 2ohm door speakers with the 2ohm dash Infinitys through a crossover or something to make them one big 4ohm speaker connecting to an amp (or headunit, but headunits never produce enough power for high-end speakers to work properly).

1990 Mercedes-Benz 300E-24
Reply With Quote
Old 04-29-2017, 04:25 PM
Registered User
Join Date: Apr 2017
Posts: 2
Thanks for the post.

I have a '93 W124 coupe, and decided to bite the bullet and upgrade the (dreadful) stock speakers. After prising them out, I cut away the "excess" foam around the dash's speaker holes until they were opened out to the bare metal. Each circle is around 114.5mm in diameter.

The whole thing is a bit fraught because the coupe has a steeper windshield angle than the sedan/wagon, meaning there's even less space to work in. With judicious razor blade carving of the foam immediately around the apertures, I managed to shoehorn in a couple of Focus ISC130, which are 5ľ" coaxials. There's more space on the passenger side, but I was still unable to drill any holes for mounting screws so wound up using butyl rubber sealant to cement them in place on both sides. On the driver's side I was obliged to remove one speaker lug and cut away some of the black plastic stiffener framework on the underside of the speaker grill to make room for the tweeter. I was unable to smooth the butyl sealant very evenly on either side and it looks a bit rough, but that's all hidden once the grills are back on.

At first I thought the speakers were rather tinny sounding, but after several hours use at moderate volume they seem to be "deepening" quite well. They certainly sound a LOT better than the originals.

I'm currently installing a Kenwood KSC-SW11 subwoofer under the first-aid flap. This is turning out to be a little more complicated than anticipated so I'll post with my observations when (if!) I finish.
Reply With Quote
Old 12-11-2017, 09:01 PM
Dubyagee's Avatar
All fields are required
Join Date: Jul 2006
Location: SE
Posts: 4,401
Can someone fix the pics in the first post. Im going this route and would like to see some pics.

Sent from my iPad using Tapatalk Pro
Reply With Quote


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

All times are GMT -4. The time now is 03:25 AM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page