After eight straight months of messing around with the stock audio system I finally discovered the combination of components necessary to produce beautiful, detailed, punchy audio. It's not crazy expensive or invasive and you can do it in stages.

This is not the "Glovebox Aux In EQ Mod" I'm always going on about either. This transforms the sound globally so you can enjoy your IPod, audio discs, DVD discs, SD or PCMIA card, Music Register, USB and keep all of your COMAND integration. (That said, nothing sounds better overall than the EQ mod, but its relative)

I should point out that I just installed a set of Focal KRC 100 component speakers in the front doors, however I didn't hear a huge improvement in quality over the stock H&K component speakers, but obviously now I can't go back and see how Stage 1 sounds on its own. I can attest that the Focals with their very expensive tweeters sounded like garbage until the Bose tweeters went in.

Also, I had the front door interiors treated with "Hushmat" deadening material so I may be able to handle a little more bass than stock. Otherwise I have a stock H&K Logic 7.

Stage 1:

Parts: (1) set of W220 Bose tweeters. (Ebay).
Tools: Wirestrippers, electrical tape.

Detach the tweeter panel from the door by first rolling down the window, then grab the tall side and pull inward toward the car's interior to release. It snaps in and out easily.

Next, pop the H&K tweeter out (it snaps in). Cut the factory wires leaving yourself enough wire to work with. Splice the Bose speaker leads in (pay attention to polarity), pop the Bose tweeter into place and close everything up. Repeat for the other door.

Stage 2

I recommend a shop do this for you, since it involves disassembling the doors, and some modifications to the speakers.

Parts: Focal KRC 100 2 Way Component Speakers, W220 Bose Tweeters (unless already installed in Stage 1.)

Make sure the shop sets the crossover adjustments as follows:

Tweeter: -6db
Woofer: Hi

Note that the installer is going to look at you like you're nuts when you tell him to leave the Focal tweeters in the box and use the Bose instead.

Stage 2 ain't cheap at around $1,000 parts and labor. Stage 1 is cheap and a breeze and you'll hear immediate improvement from just changing tweets. The mids and highs will sound smoother and better detailed and the "hollow" sound from the H&K will be reduced.

I have to say the combo of the full mod sounds terrific across all sources, and an outboard DAC and EQ via Aux In is on another level entirely.

 

I can't remember the model, but, the top end Alpine silk domes are also very good. I think they are superior to the Bose tweeters. They aren't cheap but what is? This could be a good alternative for stage 1. They are very smooth.

 

Hard to say. By the numbers the Focal tweeters from a $600 component set should sound better than all of them. I guess if you have a set of the Alpines on hand try them out.

If I were buying a set either way I'd use the Bose because I know for sure they get the job done. They seem to de-emphasize the upper mids right around the 2500 - 4000 htz range and then they're right there for the rest of the top end.

You get very sweet, smooth highs and good presence but no brassiness or harshness even at high volume. Luckily the tweets in the 221 are so easy to get to and play around with it's not a big deal to try a few different options to see what sounds good to you.

I will say that the Bose tweeters meld really well with the Focal midrange drivers using the Focal's crossover, and also with the stock 8" HK door sub. Instead of hearing very localized highs coming from the sail panels, it's more like the whole door is producing a clean, unified, full range sound.

I'm glad I went with the Hushmat treatment as well. It tightened up and reinforced the bass so well I ended up removing the powered sub I'd installed in the trunk.

 

Thank you Mike ,really appreciate that you share your findings with us !

Congratz with the Breakthrough!!!

Hopefully someone here on the forum can find the M-B partnumbers as I would prefer to order the tweeters new etc.

 

Take your local MB parts department this VIN from an 06 S500:

WDBNG75J56A461367

Should be the same tweeter unit for front and rear doors but if not choose the fronts. Interested to know what the price is for those new.

 

Looking at this

http://www.mbpartsworld.com/showAsse...String=tweeter

is it number 140 or 240 on the diagram ? Thanks !

 

Neither. Those are the door woofers and the kick panel midranges. The tweets are in the upper sail panel (the wedge where the outside rear view mirror mounts)

They must be in another diagram.

 

Update: OEM 220 Bose Tweeter Part Numbers

The Bose tweeters are sold as a unit along with the Bose woofer (located in the door) The part# for the assembly (One tweeter and one woofer) is A2208201002. Probably not cost- effective unless you have a home in mind for the woofer.

In related news, the Focal's have now had a chance to "burn in" a bit and they sound more amazing every day. In fact, I pulled the Clarion EQ, ground loop isolator and headphone amp out of the car since they're no longer necessary. I'm now running the COMAND stock, although I still get the highest quality using the IPod via the external digital-to-analog converter and the Aux In.

However I did load up the disc player for the first time since I bought the car last August, and connected a USB drive with a bunch of MP3s, and put some tracks on the Music Register for good measure and they all sounded very good. To me those sources were un-listenable with the stock front door speakers.

I think I can still get some improvement in tightening the mid bass so I scrounged up a set of W220 Bose woofer/tweeters from EBay to use in the rear doors. I also have a set of 4" MTX coaxials that I'm going to try in the parcel shelf to replace the stock 4" mid range drivers Harman Kardon used as the rear surround speakers.

 

Update: Rear doors and Parcel shelf

Now that the fronts sound about as good as I could hope, I'm addressing the last two trouble spots: The two-way speakers in the rear doors, and the two 4" surround speakers that flank the sub in the parcel shelf.

These are a lower priority than the front mids and tweets by a wide margin, and the system sounds good across all sources with just the fronts replaced, but I think there is some marginal room for improvement.

I purchased and bench-auditioned a set of 6" Bose woofers from the W220, but they proved unsatisfactory. I was surprised, because they actually sound great in the 220.

I have a used W221 rear door speaker module enroute from EBay and once I confirm its specs I'll need to find another woofer, likely another Focal product. I plan to use a second set of 220 tweeters in the rear doors as well since they're so clean and smooth.

The rear surrounds are the same shrill 4" mid range speaker that wreaks havoc up front in the doors, but they get a lot less signal as surrounds. I'm replacing those with inexpensive but nice sounding MTX Thunderdome coaxials when the car goes back to the shop for the rear doors.

 

After auditioning the new Burmester audio system in the 2015 S550 and making a couple of cabin recordings in the '15 and my 2010 I was able to get a better idea of where I still could make some improvements.

On the first pass I planned on replacing the stock 8" woofers in the front door with drop in replacements by Focal but availability was an issue. The shop is checking for inventory now, however the Focal rep recommended we consider a similar 8" shallow mount sub (also built as a drop in replacement for BMW) by German manufacturer Gladen. The Gladen speaker looks a little less robust than the Focal but is half the price. If the Focals are available we'll be installing those, otherwise the Gladens.

For the rear doors I auditioned a set of Hertz high efficiency 6 1/2" 2-ways. My concern is that in surround mode (which I use exclusively) the rears aren't getting a lot of power and a less efficient speaker might not have enough output. I have a 2nd set of Bose W220 tweeters for the rear doors in the event the Hertz tweeters aren't doing it, but at the demo the Hertz tweets sounded fine. We'll be installing Hushmat in the rear doors as well.

Lastly depending on ease of access I plan on replacing the two 4" rear surround speakers in the back shelf with the MTX units. This isn't especially critical so if a bunch of the rear interior or trunk has to come out I'll skip it.

 

Update: Rear Doors & Rear Deck

We completed the replacement of the OEM rear door speakers, as well as the two 4" surround speakers on the rear parcel shelf. The rear doors take a conventional 6.5" 2 way component speaker. The rear door woofer has its own enclosure, and the tweeter (same as the tweeter in the front door sail panel) mounts directly to the inside of the door panel itself.

The rear deck was a larger job. The rear seats had to come out, as well as some of the trunk lining. We used Hushmat again in the doors and rear shelf to suppress any potential rattles.

The outcome of swapping out the rear doors and rear surrounds was a slightly livelier high end and the "surround" effect (Logic 7) is more pronounced, making the cabin feel bigger. Equipment wise, I spent quite a bit less than I did for the Focals in the fronts.

The rear doors got a $189 set of Hertz DSK 165.3 6.5" components.To be consistent I swapped in a second set of Bose tweeters from a W220 into the rear doors rather than using the tweeter provided.

For the rear surrounds I used a relatively inexpensive MTX Thunder40 coaxial ($50). The factory rear surrounds are on a band pass filter that cuts the highs, so the coaxial functions as a straight 4" driver.

The net result of using Hushmat sound deadening material throughout the install did tighten up the bass and completely eliminated rattles. The factory subwoofers (one in each front door and one in the rear shelf) produce more than enough bass and if you're able to turn them up without rattles they eliminate the need for an external subwoofer.

Bottom Line:

Given the cost (mostly labor) of doing the rear doors and rear deck my recommendation would be that you not bother. Those speakers get so little signal relative to the fronts that the factory drivers are fine.

Putting your budget into the front doors would make the biggest impact.

W221 Harman Kardon Logic-7 Speaker Breakdown