Geokop

I thought that there is place up to around 40mm in the front doors. Maybe i am mistaken though..

Mike5215

I have a spare W205 4" front door speaker and a spare MTX Thunder 40. Depth looks the same when you line them up side by side.

vladarh

There's approximately 39mm of space, but the issue is not the depth alone. It's the conical shape of the space for the speaker. The ones with a wider magnet don't fit. That's why most of us installed the Focals. They have a very small magnet (but a powerful one).

ennedomi

Hi, I would like to improve the base sound system of my GLC.
I agree with you: the sound is very bad but I don't want to change too many speakers and amplifier. My idea is to add only two new tweeters in the standard hole: by the way, connecting the new tweeters in parallel there could be a serious impedance problem.
Do you have any suggestions (model, filter, impedance adaptor)?

Mike5215

Adding a little impedance isn't problematic. The amp will actually run cooler (and produce slightly less wattage). Going the other way, reducing impedance, has the opposite effect and can be detrimental to the amp. For sourcing, www.partsdirect.com has a lot of car tweets. Good pricing too.

ennedomi

After a long analisys I should decided to add the original tweeter. It's really strange but I've seen that, in the burmester wiring diagram https://2.bp.blogspot.com/-L5TqoQCXO...25283%2529.jpg , the tweeter is just connected in parallel to the midrange with a simply connector... This means that up from 3500hz the impedance go down under 4ohm boosting the high frequency.

Mike5215

There's a capacitor glued to the tweet that serves as a passive crossover in the Burmester system and limits the amount of signal it gets. I'm not sure there's a relationship between frequency and impedance honestly. There may be, but I've never heard of or considered it.

ennedomi

Another bad surprise....
Adjusting the balance/fader, I found that the subwoofer is only connected to the channel front right. Vladarh said that "The subwoofer is bridged to FL+ and FR- connectors" but it does not seem to be so...

gsd99mg1

Hi vladarth. I'm about to buy the m 5dsp. Do you run it in low power mode or did you need to step up the battery cable and run it in high powe mode to be abke to get your morel subwoofer going? ( i bought the morel you suggested).

Also, i'm taking the car to a pro audio shop to have everything installed. Do you think i can skip one of the customized cables (45 euros each) and have them make the connections? Could they make do with the original cable instead of the PP-iso with a little bit of extra work?

Thanks!

vladarh

The subwoofer is indeed connected that way, and yes, it's only going through the front channels in the Audio 20 menu. However, when I connected the 4 channels to the new amp, all of them had full signal range - including bass. I don't know how this is possible but that's the way it is.

vladarh

I'm running it through the plug-n-play cables in low power mode. It doesn't influence the woofer. That output is always 90W, it's just the door speakers that are limited to 4x35W (instead of 4x60 in full power mode).
As for the cable, I'm sure it's possible to make it, but here in Norway that would be so expensive that I didn't even think about doing it. I would still go with the original cable, just to be on the safe side - but that depends on how confident you are in the shop and their "expertise".

gsd99mg1

Thanks for your reply. I understand from the specs that the woofer amplification is 180W in high power mode. anyway, I bought the same woofer you are using, so if 90W is enough for you it should be enough for me.
I finally bought the ISO cable too. Probably somewhat cheaper to make here in Argentina than the 45 Euro it costs, but it gives me peace of mind and also, without patching cables, will be easier to take the m 5 out of the car when i sell it

Geokop

Vladarh, on the comment earlier, i think its normal that the head unit is sending full signal in the audio 20. The capacitors on the speakers are limiting the frequencies.( i think so at least)

By the way, where in Norway are you? I leave in Trondheim.

ennedomi

I would prepare a reversible "plug & play kit":

• a male connector (Delphi? What's the name?) to be connected to the door original midrange connector
• a female connector to be connected to the midrange
• a female connector to be connected to the tweeter
• original tweeter A2228202200: however this part is not findable but there are a lot of mercedes tweeters on ebay: which are compatible codes?
• plastic sponge to be inserted behind the tweeter cover

Mercedes dealer asked me 90 euros for tweeters and 200 euros for installation!
Do you know where I can buy the original tweeter and the three connectors 2 pin?

vladarh

I'm in Stavanger (you can see it in my signature ).
As for the signal range, that's not what I meant. The point is that the woofer gets the signal from one front and one back speaker and when you move the fader in the headunit to back you don't get any bass. Strange.

gsd99mg1

Vladarth, did you change the dsp equalization when you added the morel subwoofer, or did you live it the way it appears on your guide?
Also, did you add those dips in the eq in order to achieve some separation between frequencies or did the automatic calibration software shape hise curves in order to compensate for aberrations inherent to the car surfaces and speaker positioning? I bought the exact same equipment you did (speakers and amp) so my results should be exacly like yours.

gsd99mg1

Also... could you upload your dsp settings? It shoud be possible to export as a file and post it... thanks!

vladarh

I made lots of changes. Couldn't get that perfect setup. Here's the one closest to that. However, check if the input EQ is modified when you load the file. I'm not sure that it works, and that's the most important part. I also had to modify the standard inputs and Audio 20 settings to remove the distortions I got.
I think the signal coming out of the HU is so bad that it needs heavy mods to get the amp to work properly. Apart from the input EQ mods, I had to put the HU EQ to -10,-10,-10. It's only then that I got rid of the distortion that appears near 300Hz.
The dips, as you call them, were made by the software to compensate for the terrible signal coming out of the HU. Mercedes guys had to do heavy EQ mods to get the 1$ speakers to sound like 10$ ones (their guideline was - they still sound like crap, but most of the people won't notice).

Mike5215

Don't feel bad. I'm still tuning the Audison system on a weekly basis. It's getting better though. Almost impossible to get the midbass right in a car with no actual woofers. If I ever meet the genius who came up with Frontbass I'm going to kick him right in his Frontballs.

Are you using an iPhone as a source? I found a really cool DSP app you might like.

vladarh

I'm using an iPod over USB, just to avoid Bluetooth loss.
But you're right, it's an ongoing battle
I can hear the speakers settling in, so it's time to do a re-tune

Mike5215

If it's an IPod 5 (Touch) get the Aphex AudioXciter app. Un f'ing believable power and *****. Pay the $3 to unlock Custom. Buy ya a beer if you hate it.

gsd99mg1

First of all, thank you for all the info and help. You've done tremendous work.
About the distortion, i guess the culprit is either the crappy amp or poor eq baked into audio 20. If the source is bad quality, no amount of dsp can make that source sound good.

Would it be possible to take the digital, un-amped, unprocessed sound from audio 20 and use it just as a pre-amp?

If the burmester equipped cars have an external amp fed by optical, it should be possible to get that optical output and use it to feed the m5 or whichever external amp one gets, so that it amplifies a clean source instead of trying to clean up garbage.

Mike5215

Unfortunately the fiber optic system MB uses is proprietary (not toslink) and there is no aftermarket module capable of intercepting it and converting it to analog. It's also a loop, where each component passes the optical signal along to the next. Take one out, the loop breaks, and nothing works.

Absent any way to take signal from the optical low side, you're left taking speaker level signal from the high side and using that to feed your new amps.

On the 205, you actually need an additional processor (JL Fix82 or equivalent) in order to strip out the Vehicle Noise Compensation, which also does output fiber optic via standard Toslink, and that in turn can be sent to your new amp digitally.

The Match on an A20 is performing the function of a line level converter, an analog to digital converter, a digital signal processor and a multi-channel amp in a form factor the size of a pack of cigarettes. It's pretty remarkable.

gsd99mg1

I know it's remarkable. What a pity, though, that mb forces these extreme measures where you would need nothing more than decent amplification and speakers. My home amp doesn't even have tone controls, let alone eq, and souds amazing.

vladarh

It's an iPod 6 Touch
I'll try the app w/ or w/o the beer