nicolas1

This is my first post. I want to share what I did with my stock audio system on the W211.

I'm an audiophile and the stock HiFi on my E320 was embarrasing.

I took out the AGW and tried a few things including trying to put in amps, etc. After lots of wrong turns, the simple solution was surprising for me. My system now sounds "Audiophile" - for a car.

Background:
My car has the Audio 20 with AGW in the trunk and a stock subwoofer. Stock 165mm woofer and 38mm tweeter in each door. I understand the amplification innards of all the AGWs (A20,A50, Command) are the same, only the processing (Surround, 7.1, etc) is different

My Restrictions:
Front door woofers are glued to the panel. I could not remove them or gain access to the rear connector

Rear door speaker connections could not be accessed - I didn't modify these... yet.

The Subwoofer connectors and crossovers (yes 2, for left and right channels) were accessable from the hat rack as the sub fires into the trunk. I assume it is designed to be 180 deg out of phase since it fires in the "wrong" direction.

The front tweeters and front door access panel (where it meets the dash) are easily opened. They just pop out.

Why I did it this way:
I was originally going to install new amps, electronic Xovers, the works!!
BUT:
1. There is no space to hide decent sized amps
2. There is no wake-up line for the amps
3. I didn't want to open any of the sills or panels to run new speaker wires

What I did:
I added a Focal 165 crossover to each front door. These are top quality crossovers from my previous setup. The Xovers fit in the access panel of the door (where door meets dash)

In the access panel is a connector (ie. input from AGW to connector to tweeter and woofer).

I opened the connection and used the speaker output from AGW as "IN" for the Xover.

I took off the wire at the Tweeter (in the triangular moulding at the window), & pulled these through to the access panel and wrapped them in insulation. These are no longer used.

As the tweeter is disconnected, the wires now only lead to the woofer & I connected this to the Xover "Woofer Out". BTW since the wires are only connected to the woofer I tested the woofer impedence to check that it matched the Xover. Mine are 4 Ohm woofers (actual 3.8 Ohms)

I replaced the stock tweeters with Focal TN46 (4 Ohm) which fit perfectly (after trimming the border) in the round holder in the triangular moulding. This tweeter is an old model, the new ones are much larger. These tweeters matched my Xover.

The stock tweeters are 8 Ohms with a 1st order HP Xover (capacitor only) crossing at 3800 Hz. If you re-use these, you need to bypass the stock Xover (capacitor).

I ran new wires from the Tweeter to the Xover (tweeter out)

FYI: Matching a Crossover to the woofer and tweeter imprdence is very critical. A speakers impedence changes with the frequency and is NOT 4 or 8 ohms at the Xover freq.

1st listening test: Vocals were very clear - mids and highs were almost audiophile (for a car) BUT the mid bass and lows were muddy.

The stock sub Xovers (theoretically) crossed at 120Hz (and looked 2nd order - 12 db/oct), but didn't seem to do a very good job as I could still hear female vocal coming through the sub (which shouldn't happen) and causes the lower freq to get muddy.
I bypassed the original Xovers and installed 2 Kicker SW100 Low Pass crossovers to the Sub. These cross at 100 Hz and are 2nd order Bessel Filters (good stuff!!).

NB. I desoldered the original Xovers. leaving them connected would cause them to blow.

2nd listening test
The lows really cleard up after this. I can say I'm pleased. With clearer bass, the vocals cleared up even more, giving more dimension and spaciousness. There is still a little muddyness around the 150Hz range that is either caused by the rear door speakers or the bass control on the HU/AGW. The Bass control on the HU is old fashioned and just magnifies everything below 250Hz (like old radios)

Conclusion: The stock AGW amp is more impressive than I expected from tiny components. It gives a clean warm (tube like) tone and has good imaging.

What was lacking from my system were good crossovers. Most of you, who have built speakers and crossovers, know how pricey the good capacitors and coils cost. This is where I believe MB tried to cut costs.

The stock speakers (sub, woofers, tweeters) aren't top notch like Focals or other reference series, but they aren't the rubbish some have said.

The quality is comparable to the 2nd best range for normal speaker brands and/or
the 3rd best range for top notch brands. In other words - above average

What the system can't do:
I can't give thumping bass for heavy metal music. The stock amp just isn't powerful enough - not enough "grip" on the sub.

That said, for Jazz and pop vocals, the drum beats & double bass come through clear, loud and hard hitting.


If you're trying this yourself:

The desoldering and connection of the sub Xovers is tricky. Its a cramped space at the hat rack, be careful not to burn the seats, demister or hat rack.

Quality crossovers are hard to find. Matching them to speakers of a different brand (ie stock system) is even more difficult.

A good quality crossover makes a world of difference. No matter what people about specs on paper, hearing is believing. Different materials such as polyprop capacitors, teflon insulation, silver wires, copper wires do make a difference. But what you use is up to what kind of sound (& type of music) you like. More expensive is not always better.

I hope those of you reading this will find it useful...

W0n6_3d4n

Very interesting mate .

Bugsbunny

Nice detail. I just wished you lived closer to me now. hehe

nicolas1

ajm0824 - your PM box is full. Attached is my reply.

Hi,

I saw your earlier post when I was researching audio upgrades.

I've had a few more days to listen to my 'improved' system. The sub's bass is surprisingly good, but it can't "thump" because of the amps's limited power and the stock bass control.

I believe the cracking sound and muddiness in your system is due to the crossover (& crossover point). The cracking is because the subwoofer is being foreced to play frequencies (mids) which are out of its range and causing the amp to clip.

A properly set Xover also allows the amp to do less work and apply it resources to the other channels.

I would recommend the Xover fix first, if there's still not enough bass, then you can try 1) a new 10" sub which is easier to drive (ie. high 90+db output/W) then 2) a bigger bass amp

Before I get ahead of myself, where did you find a switch 12V output when you installed the bass box? That's the main factor in deciding to change the amp first or to use an easier to drive sub

I saw a couple of SW100 low pass crossovers on ebay last week. But its not listed this week. Try the closed auctions if you're a registered e-bayer. I don't have alternative suggestions on Xovers to buy. but if you have electronics experience, it relatively easy to build...

BTW, don't waste your money on Xover with a diff Xover pt (eg 150 Hz) the proper Xover pt for the W211 is 100 Hz (assuming continued use of stock door woofers)

If you pop open the speaker grill on the rear hat shelf, youll see a couple of wires connected to the sub, you can also see some capacitors and coils - which are the Xovers.

I desoldered the tinsels* where they connect to the Xover and put a tiny connector on them. *Tinsels are the wires from the speakers voicecoil.

To determine +ve & -ve, I used a multi-tester to check the impedence/resistance between the original Xover "IN" & the connections I desoldered. The -ve has almost no resistance (as it normally a direct connection). The +ve has more resistance as current has to pass through the coil & cap.

If you connect the polarity wrongly, you get a flat spot ie. suddenly at that freq, it sounds like someone's thrown a towel on the sub.

This should clean up the low end, and you'll be surprised how much clearer the mids will become.

An alternative is to change the sub, add a big amp (with High Low converter) and use the built in Xover of the amp (if it has one). This could be easier for your installer.

Could you let me know where you tapped the 'remote on' for you amp when you install the bass box. Thanks.

ajm0824

Thanks, I saw some of the closed auctions and will continue to look.

Regarding building my own xover...
would using the specs listed on this calculator work well (4ohms/100htz 2nd order; COIL: 6.36639mHy, CAPACITOR:397.89909µfd)
http://www.the12volt.com/caraudio/crosscalc.asp#cc
do you have any other online resources for a DIY if I should have to resort to building myself.


some silly questions..
1. I would need one xover per voice coil, right?
2. and each voice coil is 4 ohms?
3. the sub in question is the one that is part of the harmon kardon upgraded stereo system?


As I hooked the amp up in the trunk... I found a 12V turnon coming out of the fusebox (left side of trunk) (next to audio gateway I think)... I will check exactly which one...


Not sure what I'm going to do with the box if a newly crossedover sub suffices for me. If it doesn't I still have the 400W punch amp and the 2 kicker comps... maybe build a smaller enclosure for just one of the 10" subs...)

Thanks

ajm0824

building low pass xover... these specs work? thanks

nicolas1

I also use this site for calculating Xovers.
http://www.apicsllc.com/apics/Misc/filter2.html

FYI:

1. the stock sub Xovers and SW100 Xover are 2nd order. The order of the Xover affects the phase. If you switch to a 1st or 3rd order, you may have phase issues with the reset of the system.

2. The SW100 is a bessel design. I don't fully understand how it works, but it just uses diff values for cap & coil. The URL above has a bessel Xover calc. I guess you already know that its almost impossible to buy the exact values calculated, normally +- 10% is the acceptable.

3. Large audiophile coils are expensive, but have *much* less distortion.
From http://www.roger-russell.com/drivers...ssovernetworks quote "[Mcintosh coils] Distortion is only 0.2% at 20 watts and remains below 1% at 600 watts. A few iron core coils made by other companies have distortion of 1% at 20 watts and 15% at 100 watts.

The SW100 is a good deal if you can find one. If you can't get one,
I hear that a good source for parts (though I've never used them) is www.solen.ca or madisonsound.com

1. You'll need 1 Xover per voice coil - total 2 units
2. My car's sub is 4 Ohms for each voice coil. Better to test your sub considering the US spec, Euro spec differences.
From the rear hat rack, disconnect the sub input wire, use a multi-tester to test impedance at the sub's tinsels.
If you don't disconnect the input, you may read the impendence of the Xover and amp instead.
3. My sub is part of the basic Audio 20 sound system for E320s in Singapore. The E200s here don't have them (and really sound bad). I've read MBUSA service docs that state that the sub is an "option".

I hear the HK Audio gateway has a pre-out (line level output).

I found a switched fuse (#7) in the trunk that is meant for the wagon (T-model). But it only switches on only when the key is in position 2. My w211 can have the radio on in when the key is in the 0 position and only switches off when the key is removed. I want to maintain this functionality

Hope this helps

nicolas1

I hooked my old boxed subs and car amp up to an "AC to 12V coverter" and use it as the sub for my home theatre...

ajm0824

my neighbors are gonna luv me!

ajm0824

Thanks for the resources... gonna try for couple weeks to locate the kickers then embark on building my own ...

the sub is the one w/ the HK7 260mm duel voice coil.... I'll test the impedience without the amp to make sure...


If I recall correctly when I found the 12v it was powered by the radio in both pos 0 & pos 1. towards the bottomof the back box.... I don't know i fit was #7 but I'll try and check for sure tomorrow after work. (chart is not in the manual ... just on the fuse box..)


Thanks!

ajm0824

I don't have anything hooked up right now but I shared an in use slot (Slot#1) in the trunk fusebox. Think it behaves how you want (w/ radio on in pos0 or pos1)

benzmodz

I have to disagree with your analysis of the door speakers. It only takes me a few minutes to get them out.

They are not "attached" in any sort of permanent way.

nicolas1

Hi Benzmodz,


I would change the front door speakers if I could. I tried looking for clips, twisting, etc with no luck.

Could you share with us the procedure to remove the door speakers on the W211.

I noticed that you drive the W203, were you refering to speakers on that car?

Thanks.