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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.
I'm looking at your eq / crossover settings and I notice that the high-pass settings for your door speakers, and the low-pass for the subwoofer are very different. Therefore you are getting a lot of frequencies generated by the sub and the door speakers. I believe that might be the cause for the distortions. from what i understand, you should set all your door speakers at the same high pass frequency, and use that same frequency (or one quite near that) for the subwoofer low pass, in order that the sum of the sound level produced by all speakers at any given frequency remains constant.
Your setup would produce a higher level for frequencies between around 124 - 300 hz which is where all speakers are working unfiltered.
This is based on the write-up you made, I haven't yet looked at your uploaded file since I haven't yet received the m 5dsp.
No, it's not that. The distortion happens even when the woofer is off. There's a sound near to 300Hz that is generated by the HU that the amp just can't handle. The only way was to push down the EQ on the HU.
I set the woofer higher to gain some of the mid bass that is lost in an 8"+4x4" configuration. Ideally there would be a 6.5" mid-bass to fill the gap and then you could set the cut-offs precisely, as you said. Unfortunately in the W205 we need to "circumvent" the design flaws.
I tried going higher with the woofer, but it only helped a bit.
thank you for all your help. i almost want to get rid of that darned audio 20. one could get a remote for the m5, use an aux input to feed it directly from an ipod, and get a proper, clean audio source. too bad you'd loose all phone integration if you did.
i'll install the amp and focals when I come back from holidays in about a month, and let you know if I find any way to improve it.
I tried that as well. Got a bluetooth receiver with an optical out and connected it directly to the amp. Much clearer sound, but in the end I went back to the Audio20. Too much trouble operating everything from the phone - volume, track changes... as you said, all needs to be done on the phone that way.
Yeah, for GSD, don't get hung up on the numbers. Tune it by ear using material you're familiar with and stop when it sounds good. Nothing is sacred as far as "the rules" go when I'm tuning a car. The trick is to know what you're listening for vs what you're getting and understand the equipment well enough to move things in the right direction. There are a lot of moving parts in a tune so focus on one parameter at a time. I usually start by soloing the woofers + sub, get the kick drum sound and bass guitar sound where it's punchy, clean and distinct. Then I'll solo the mids/highs so that the vocals and guitars have presence but aren't brassy or shrill. It's a thin line. I want the snare drum sound to crack and cut through, the hi hats to have a nice chip sound and some meat to them, and the ride cymbals to have a clean bell sound with audible sustain.
Sometimes I'll get done and look at where the settings all ended up and if I were strictly looking at the numbers I'd be thinking WTF?
The physical constraints of the 205 make it a bear to tune. I'm still listening to more material and making little incremental changes, so take it slow and when your ears start getting fatigued pack it in for that session and come back fresh.
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.
I haven't yet been able to even start playing with the dsp (i'll install it in 3 or 4 weeks, when i come back from holidays), but that most to toslink converter sure sounds promising. Not cheap but if it is what it takes to make the dsp and focal speakers deliver it might be worth it!
It would work on a Burmester set up (which is optical from the HU to the amp in the trunk) but the A20 isn't on a MOST ring. The HU and amp are a single analog unit. On an A20 you'd want to use the harness adapter outlined in Vlarth's write up.
It would work on a Burmester set up (which is optical from the HU to the amp in the trunk) but the A20 isn't on a MOST ring. The HU and amp are a single analog unit. On an A20 you'd want to use the harness adapter outlined in Vlarth's write up.
doesn't the burmester have the same a20 HU as preamp? If so, it should have the optical connection somewhere. Maybe opening the HU it is possible to find the connector.
The multimedia package with the 8" screen should have a separate amp in the trunk that's fiber optic from the HU. I haven't seen an A20 on a car with the MMI so I can't say for sure. If you remove the right quarter trunk liner the amp would be mounted there. The MOST cables are orange.
I played around a little with Dynamatting the front doors in the speaker area. Thought it might help reduce the distortions I'm getting. Unfortunately there's no difference. But at least it proves that the distortion is software based, nothing wrong with my speaker installation. The only way to get rid of the distortion is to move all three EQ bands to -10. I guess the Match amp can't fix the sound enough to avoid the noise I'm getting at 300Hz. The best way would be to use the JL Fix like Mike did. That way you get a nice clean signal that you can actually work with.
Im planing to upgrade my base sound system with audio 20 . In my previous w204 i did it with alpine processor ,aftermarket speakers , and couple of amps and tons of dynamat. Car has some success in car audio competitions ( sound quality level - EASCA ) Most of the job done by my friend ( pro car audio instalator ) .
This time i like to to it myselfe .I have been study Mike blog .https://w205audio.wordpress.com/2016...rmester-audio/
This is very helpfull and i found good information there.
Im wonder how is the volume contol working if jl fix 82 is connected with fiber optic to the Audison amp? . If im not wrong , digital signal has no information about volume.
I played around a little with Dynamatting the front doors in the speaker area. Thought it might help reduce the distortions I'm getting. Unfortunately there's no difference. But at least it proves that the distortion is software based, nothing wrong with my speaker installation. The only way to get rid of the distortion is to move all three EQ bands to -10. I guess the Match amp can't fix the sound enough to avoid the noise I'm getting at 300Hz. The best way would be to use the JL Fix like Mike did. That way you get a nice clean signal that you can actually work with.
You only need to try the bluetooth receiver. Since the audio is fed directly to the m5 without any intervention from the head unit, that test should be enough. If the distortion is present when playing from bluetooth (you could also use the toslink imput with a macbook or a cd player) the problem is in the hardware (speakers / speaker mounting) or the m5 settings (eq/crossover). If the distorion is only present when playing from audio 20, the problem is inherent to the head unit and could only be solved by removing the head unit from any audio processing, either passing along a clear digital signal via optical out or using the aux inputs directly (bad from ergonomics point of view as you loose phone integration and car based control of playback and volume).
I have just installed the m5 and have not started playing with it as i'm yet to install the focals. I'll share my notes when i do. But i did notice some unused connections on the back of the head unit, i believe one of them might be the MOST digital out.
Another possibility could be the rear door speakers are to blame for that distortion. Have you tried muting them? I saw on a german forum they suggested swapping them for coaxial two way speakers that do fit the space, i'll try to find the name again and share it here. They were not too expensive, something like 100 euro for the pair, they may be worth trying out.
I tried the Bluetooth on a direct optical connection and the sound was perfect. Clean and crisp. Yes, the problem is inherent to the HU, but only at higher volumes. I added 5dB to the Match pre-amp and I now need to go very loud to get to the distorted sound. I'm happy with the setup now.
Hi All.
This is my third post here and I wanted to share my experience with Audio20 embarrassing sound system.
Of course I read all possible topics including drive2.com website.
So as I had Audison system bought for my previous car and never installed I decided to use it here in C class.
My components are:
- Audison Prima AP8.9bit as DSP and amp for speakers
- Audison Prima AP1 D as monoblock for sub
- Audison DRC as a controller
- Audison AP1 as a front doors tweeters
- Audison AP4 as a front doors mid
- Audison AP6.5 as a front woofers (installed in original designed place)
- Audison APX4 as a rear doors coax
- Hertz ES250.5 in sealed enclosure (speaker dedicated to sealed enclosure but will build new ported enclosure to reach lower freqs.)
Amplifiers has been installed in a trunk so all wiring (power and signal cables) had to be run. I am using high level signal from HU connected to DSP. Then for a door speakers (front separated and rear coax) I am using original cabling. For woofers cables are new. Passenger side "frontbass" has been modified to fit 6.5' woofer. Driver side originally was empty (blank panel) so I did buy original Audio20 speaker (after market) for a RHD cars which as per my surprised is different shape and fixing points then blank panel. So panel has been modified to fit 6.5' woofer.
As for installation part it is not difficult to run cables from battery to trunk for amps supply but difficult to find position for the fuse next to battery.
Then frontbass original speakers location is pitiful (for the sound and space).
As well as mid range speakers - I used 4' from Audsion Prima series and unfortunately modification of doors panels as well as door were necessary - not enough of place + depth. Original speakers magnet is a toy. Mercedes saved money everywhere where it was possible including assembly the car (I will post picture of car cabling - it looks like accidental non qualified people where doing a job on 50k Euro car). Most of the clips which have been open with proper tools (not talking about door panels which can be removed quite easy) are one time use - new required.
4 days of work from early morning until late night and still not finished - final touch with assembly panels plus new sound tune is required.
I did not use damping materials on a door panels - for tweeter and mids there is not vibrations strong enough. Only place to damped is a trunk as 250W RMS sub is making a lot of body panels shake.
But even with this job done w/t final sound tune I can say that I finally get what I was expecting from original sound system. Finally I can here high and low freq. and little less mids as there where to much in original setting.
Why Audison Prima? Easy to setup and powerful equipment for a size and money. Integrated DSP is doing a job.
I do not have a lot of pictures but if any help is needed I can give an advises as I already disassembled half of the car interior. And I can post my configuration plus equalization config file from Prima as this can be helpful for anyone which is thinking to upgrade own sound system. Really worth to spend some money and free weekend to do an upgrade.
And this is as mentioned pictures of original car cabling which was found under the carpet in some kind of cable tray (yellow thick cable and twisted yellow/black are mine temporary installed to check final length - rest is factory installation):
Sounds like it'll be a nice system. There's a write up on my Audison/Focal upgrade on my Burmester with a link in my sig.
The OEM speakers use Neodymium magnets which are much more powerful than conventional speaker magnets, so they can be a good bit smaller. But irrespective of the magnets, the speakers do kinda suck.
Thanks guys.
Mike5215 yes I read your write up which forced me to start my upgrade.
The reason I decided to do an upgrade was that eq setup on HU was pretty at limit and still the lows not heard as well as highs and with high volume you could hear that you reach the limit (some kind of distortion was heard). And as HU does not has VU (progress bar) then you actually do not know where is max undistorted signal level which for sq reason is important. So I am planning to add clip/peak detector led on HU output to have clean signal when I will need to increase volume at max (I have a plan to install Audison DRC in "ash tray" which I do not use at all and the LED for showing distortion will be next to it).
But still I cannot imaging why MB went this way of audio installation. To be honest I prefer to have 6.5' woofers in all doors instead of pocket for bottle which is not useful for me (I do not keep 1l bottle in each door all the time). There is a space behind the door panel to install woofers but panel has to be modified and I am not a big fan of this big modification - I am a guy which like to have all hided as original. This is also the reason I used Prima - size of amps is not taking half of the trunk. Actually my installation will not be visible, speakers hided behind panels and amps under trunk floor (lifted panel) as I would like to have quite easy access if I will need to do some mods. Only visible part will be a sub in a trunk but I have a plan already to use part of trunk behind rear seat with easy removal when I will need more space in trunk or open rear seats.
01-31-2017, 06:24 PM
