MDI ipod distortion

[chrisr_aus]

I have just picked up a new skoka superb with the equivalent of rns-510. The unit has the mdi attached but the quality of the sound from an ipod is shocking. It is very distorted at all levels. I have ensured the aux input level is low. Have tried various ipods / iphones. When playing the same mp3's via the SD card all is great but the same files via the mdi are rubbish.

I have tried reconnecting the ipod adaptor, made all files on ipod 128kbps AAC lossless or mp3 at 128kbps or 64kbps all are distorted to some degree.

Is this a problem with mdi or am I missing some part of the setup?

thanks

Chris

[FSI 220]

You arnt running Equalisation on your iPod are you?

(extra bass to make up for those flaccid white earbuds perhaps?):P

[chrisr_aus]

Equalisation is off, have also tried flat any other settings but still the same or worse

[Ryan_R]

In the HU settings menu find "AUX input level' and set it to Low. Might have to restart the HU after.

[lincs]

my glovebox dealer fitted mdi in my octavia RS is ****house as well with distortion on all compressions of music data and at low input levels.. i end up running it through bluetooth and using the mdi as a charger.

ive tested the cables and ipods/iphones in my R which has factory fitted console mdi and it is crystal clear.

so i'm guessing it could be a dud mdi cable or the connection is not in properly in the back of the unit.. i'll get em to check it out at its service in november. but yeh i know exactly what you're on about and it shat me to tears early on.

[fully]

I'm having the same issue with my dealer fitted MDI, have taken it back and they changed some part and said its working fine, well it's not, its the same! sigh....Did anyone ever get to the bottom of it?

[mythik]

In the HU settings menu find "AUX input level' and set it to Low. Might have to restart the HU after.

I've assisted around 10 members with this issue in the past.

In each case, the problem was the Aux input level was set to medium or high.

Can everyone experiencing this issue please check this setting.

The AUX input line into the head unit is used by the MDI device for audio output as well as the AUX 3.5mm jack so it needs to be set to LOW (line level) or else the MDI output will be too great and the audio will distort.

[Ryan_R]

Guess most people just don't expect it's an analog connection* since the HU can display file structure, etc. The MDI itself (there's a little box that the USB/iPod cable plugs into) with a PCB in it that does the DAC work.



* (streaming audio via wires to HU compared to digital in the sense of an SD card connected directly)

[mythik]

Guess most people just don't expect it's an analog connection* since the HU can display file structure, etc. The MDI itself (there's a little box that the USB/iPod cable plugs into) with a PCB in it that does the DAC work.



* (streaming audio via wires to HU compared to digital in the sense of an SD card connected directly)


Actually, for iPod connectivity, there is no DAC work done at all by MDI/headunit. That's only for file format connectivity (usb drives / hdds / etc) via MDI. For iPod/iPhone, the line level output from the dock connector using the dac in the device is piped through the MDI device into the headunit directly. This is how it's always been. The MDI device acts as a controller or moderator for interface display on the RCD/RNS.

This line level output from the iPod device and thus from the MDI is why it's important the gain level be set to Low (which is line level) on the RCD/RNS device to avoid input distortion (waveform clipping) resulting in horrible nasty sounding music.

[LukePolo]

I'm going to bump this one.

I have a Polo 6R (MY13.5) with MDI. It originally came with an RCD310 but I swapped it to the Bosch RCD510.

The sound quality is disgusting and distorted all the time. My AUX level is on low and my EQ is flat on both the device and the car (although I have tried everything to make it sound better)

I resorted back to the radio...

FYI - It's an iPod classic 120GB 7th Generation.

I read about this pin swap business, that's sorta out of my league. Unless there's someone on here for a case of beer could lend us a hand?

Any input would be appreciated :)

[Harrydhillon]

There is an input level adjustment in settings somewhere. Set it to low or mid. Or try restoring the iPod.


MY13.5 Red Polo GTI.
Sunroof, tint, bi-xenons, LED interior lights

[LukePolo]

There is an input level adjustment in settings somewhere. Set it to low or mid. Or try restoring the iPod.


MY13.5 Red Polo GTI.
Sunroof, tint, bi-xenons, LED interior lights

Please see my previous post.


My AUX level is on low and my EQ is flat on both the device and the car (although I have tried everything to make it sound better)

[Nuvz]

I have just picked up a new skoka superb with the equivalent of rns-510. The unit has the mdi attached but the quality of the sound from an ipod is shocking. It is very distorted at all levels. I have ensured the aux input level is low. Have tried various ipods / iphones. When playing the same mp3's via the SD card all is great but the same files via the mdi are rubbish.

I have tried reconnecting the ipod adaptor, made all files on ipod 128kbps AAC lossless or mp3 at 128kbps or 64kbps all are distorted to some degree.

Is this a problem with mdi or am I missing some part of the setup?

thanks

Chris

I know that I am arriving years after this first post.
I had the same exact issue with my IPOD 5.5 the generation connected in my Golf VI and it took me years to figure out the problem.
With experience, after long diagnostic, if you happen to connect via an AUX cable and lower the volume you NOT experience the distortion. SO that put me on the track to solve it.
Either I force the line out level to some lower using some electronics or .... just rebaseline the tracks level (mp3 or other format).

1) So I went on the second path: I went iTunes, select a song, selec the option, and lower the Volume Adjust slide one step down (center is none, so just one level on the left) and then save the song.
You can do this operation by selecting all songs at once and change the volume adjust.
Of course I will take some time to rebaseline all tracks and sync back again to your ipod, and that magically solve the saturation problem.

2) Also on the AUX level input in the car, I adjusted if to the minimum input level. I read that somebody else mentioned it in this thread / post.

So both actions 1 and 2 are required to prevent that saturation.

I am still using my that same iPOD since ages in that same car and I am still enjoying it.

I did another mod, by upgrading the internal HDD to a iflash microsd adapter and now I can enjoy ALAC format (I converted my FLAC to ALAC using XLD on mac and I love it)!

Hope this help if ever anybody is stil experience that saturation issue.
Cheers,
Nuvz

[Nuvz]

Fully agree with you on this.
iPOD sends pure analogue to via the MDI interface.
Actually I discovered (after years) on how to fix the distortion without doing any physical or electronic mods.
Try the test with one track where you experience most saturation when listening in your car, as follows:
- Select the song in your iTunes from your PC or MAC


In GET INFO, then OPTIONS, modify the volume ADJUST by reducing by one step down (or 2 if needed) and set EQUALISER to NONE.
Save and sync the song again to your iPOD


It will implicitly lower the native gain of the song and reduce or eliminate the distortion.
I happened to cross check this when you plug you ipod via an aux connection and lower the volume on the ipod.
If this works for you, then you can mass select all songs and perform then lower the VOLUME ADJUST for all songs at once. It will take some time to modify, save and resync.
FYI, I’m still using my ipod 5th Gen (ipod video with Wolfson DAC) with ALAC, that I converted from FLAC using XLD on Mac.
My next mod will be to change the internal HDD to a microsd adapter and increase storage.

I know that my proposed solution arrives years after this original post, but I am sure there are still a lot of people still using their ipod via MDI connection.

Hope this helps.



Nuvz


Actually, for iPod connectivity, there is no DAC work done at all by MDI/headunit. That's only for file format connectivity (usb drives / hdds / etc) via MDI. For iPod/iPhone, the line level output from the dock connector using the dac in the device is piped through the MDI device into the headunit directly. This is how it's always been. The MDI device acts as a controller or moderator for interface display on the RCD/RNS.

This line level output from the iPod device and thus from the MDI is why it's important the gain level be set to Low (which is line level) on the RCD/RNS device to avoid input distortion (waveform clipping) resulting in horrible nasty sounding music.