Very poor quality from ipod dock!

[reecurner3]

Basically i have installed an ipod dock into my stilo, it has a line out for aux cable and a ipod cable port for charging, when i first used it it sounded like it should, but i went to use it yesterday and it sounded terrible ( imagine you film a video on your phone in a night club and play it back the next day and you can't hear anything because the phone speaker can't handle the loudness of the music in the club and it sounds distorted ) basically thats the sound i'm getting, It's mostly the bass that is distorted but the highs do seem a little distorted from what i can tell but...

if i take the dock out the the equation, and connect the ipod straight to the HU via aux cable it sounds fine, also the same when using a CD, i wouldn't say it was the dock that was playing up because i have to identical docks, both brought at the same time, and have tested both, one of them i have fiber glassed into the car.

So i did some trial and error, i tested 2 different aux cables, both work fine connected straight to the ipod, but not through the dock.

Tested using the front and rear aux input on the HU, works fine with aux, but through dock is bad,

Tested not plugging in the ipod charger and just plugging in the aux into the dock, in both front and rear input on HU, still the same,

Tested using a different ipod cable in dock, same result,

Tested using a different usb cigarette charger, in different cigarette lighters, again, same result,

Tested a different ipod in both docks and just using aux cable, same outcome,

Due to fitting the ipod dock where my hazard light button was, i have had to relocate the button elsewhere in the car, not that i think this has anything to do with it, but just thought i'd mention, and also i have wired a 2nd cigarette lighter from the original one, but have been using that to charge things for a year or 2 so i doubt that would be the case, i was edging towards something to do with a bad ground but i could be completely wrong, but what other option is there? this has really got me in a pickle, and a little p*ssed off because after spending so much time fiber glassing the dock in, it stops working properly, and just to mention, i was using the dock before i installed it permanently, then i installed the new hazard light button, then put everything back together, so it would look like it has something to do with the new button, but i dont see how?

so if you've go any thoughts then please let me know, i think i have covered everything i have done with the trial and error but may have forgotten something, but yeah, if anyone can help i would be very grateful, thanks

 

[PuntoHowTo]

would love to help but you use the term 'aux' so much i lost track what you were actually talking about (I have a short attention span) are you talking about input on the stereo or output on the dock,

so you glued an ipod dock to your dash (would be nice to know which one) it was all working fine but now it doesn't.
everything is hunky-dory if you take the dock out of the equation but use the dock and it changes the sound quality to that of a happy slapping video?

clearly the issue is with the dock but the important thing is what have you done to it (pics needed) and how do you have it configured? what cables what Head unit how are you charging it etc, there are a few elements coming together which could cause problems also what iPods have you used and what is their compatibility with the setup you have if you have a 2.5mm jack going into the dock then you plug that into the earphone socket on the iPod then these are two completely different outputs, the 30pin socket on the ipod is a raw audio output with not amplification or processing, some devices even read the raw digital data to get a much better sound quality than what the iPod would be capable of, so you need to give more info really

the most important being what dock are you using and with which iPod/s

 

[reecurner3]

The dock is off ebay, it is compatible with all ipods, i must stress that the dock has been working for a few days, this was before i installed the new hazard light button, but i don't see how that would have anything to do with this problem, but anyways...

My ipod is a 5th generation ipod nano ( the one with the camera on it ) but i have tested this using a 4th gen and 3rd gen ipod nano and i still get the same result.

Moving on to the dock, when i brought the dock i ordered 2 just in case i messed up with the fiber glassing, and i have tested both and both are doing the same thing, and both were working before hand.

Here are some pictures to help you visualize what set up i have

I hope all of this helps

 

[PuntoHowTo]

some nice work! (you have far to much time on your hands putting those graphics together)

have you tried the ipod in the dock without the ipod cable connected?

also in one of those pics i see a huge amount of wiring modification behind the radio that looks like its held together with crimps and duct tape

 

[reecurner3]

Haha yeah i just put them together, thought i'd put some effort into it to make it as clear as possible what set up i have,

And yeah, the weird thing is, if you plug the AUX cable into the dock, then plug the ipod in without the charger cable in, press play and you hear no sound, but as soon as the charger is plugged in, you can hear the music but obviously it is still distorted, but i don't see what difference plugging the charger in would make to the output and the quality.

Those wires behind the headunit are the high input from the amp, and i wrapped duct tape around each wire for labeling not for securing the wires together, just so i know which is front right, front left, etc... i've had the wiring like this for about 2 years now and that's never been an issue,

Also i tested the dock in the house and hooked it up to my speakers and it acted exactly the same as i mentioned a minute ago, about when you plug in the charger the sound comes on, but from what i could tell the quality wasn't distorted in the house, which would rule out the dock being faulty...

This is a real head scratcher

 

[PuntoHowTo]

the only thing left to suggest then is to try it plugged into the car but powering it off the USB from something else to see if its interference caused by the cars electrical system. and try with it plugged into the car but the line out from the dock going into something else like an little external speaker.

also have you tried turning the volume right down on the ipod? does adjusting the ipod volume affect the output of the dock? change the EQ turn on sound check, turn on a volume limit etc and make sure there are no settings on the radio that would effect how it processes the audio from the ipod

if you think its the hazzard button remove it and see if it has any impact you might have created a ground loop somewhere

i think that one of these would fix the problem though http://www.ebay.co.uk/itm/New-Unive...aCables_JN&hash=item3374742193#ht_4657wt_1037

 

[volxstu]

I can think of a few issues. You say you are connected optical but that I can't see where. Your Dock may be taking a Digital Signal from the LOD of the iPod but it's all analogue from there. It is then a straight Analogue signal from there. This means all the dock is doing is adding another pass through to lower the quality of the signal sent to your HU. Ie you would have been better off Just using the Aux cable from the mini jack output directly from the pod.

The issues you are having sound a little like bit rate issues. I'm not sure how that converts to to analogue but it sounds like when you try to put for example a 32bit 48khz signal into a DAC that only works as high as 24bit and 42khz.


It's great work you have done there, im very impressed but until you get a Head Unit with optical input (or make your own direct into the DAC) it's pointless. I'm also afraid I couldn't personally diagnose the issue without seeing the car, but I hope my ramblings have helped. I will look into how to modify your HU to accept optical. At the end of the day it must only be a couple of wires that bypass any analogue stages.

 

[PuntoHowTo]

You say you are connected optical but that I can't see where.

thats because he's not connected through optical its all 3.5mm jacks

 

[reecurner3]

I have tried plugging the usb into my laptop, i only get sound for a second or two because the ipod then connects to itunes and obviously stops playing music, but it did the same thing.

And no, turning the volume down on the ipod when connected to the dock has no effect, no settings were changed on the ipod or the HU, i've been using pretty much the same set up on my HU, ipod and amps for 2 years, so i know it's not any settings, i'll have a go at disconnecting the button to see if it has any effect, and that cable could work, but the thing we need to remember here is that it was infact working with good quality audio for a few days, it was even working just before i wired in the button, when the button was wired in all the fascia and HU etc were unplugged, then after fitting the button in place, then reassembling the HU and fascia, it started to do this, one thing i probably should mention is my HU slid off the dashboard BUT i caught it before it had any contact with anything, i did think this would have something to do with it BUT, then i had a thought that it surely can't be because if the ipod works fine just using the AUX cable straight to the ipod, then why would it not work with the dock in the equation, so i ruled that out, i probably should have mentioned that before but seeing as though CDs work and the AUX inputs work i wouldn't have thought it would be the problem.

But the main thing we need to keep in mind is that it was working before, so the question is, what has changed from the point of it working, to the point where in finished with the button and reassembled everything thanks for your help so far, just gutted that i've gone through all this work and somehow i've done something wrong along the way :bang:

 

[reecurner3]

Okay so... i was in the car earlier and i pressed the button to heat up the rear window and it didn't work, and the button to keep circulating the air in the car didn't work either

so i pressed down on the new hazard switch and the hazards came on, then i tried the buttons again and it worked, so i obviously have wired the switch up wrong, here is the switch and a diagram, ignore the writing on it that was me trying to figure out what wire went where
The wires coming from the original hazard button are Blue/Black, Blue/Green, Purple/Black and White/Grey, and this is the wiring diagram that came with the switch

I don't I know i'm going slightly off the subject here, but if someone knows how to wire it up properly from what i've written then maybe i'll be closer to figuring out the ipod dock situation, because the only thing that i really changed in between the dock working and not is this button, and just to show you, here is the internals to the dock

 

[reecurner3]

Okay...so i ended up going to a local car audio shop, showed the guy this thread and he stood there scratching his head, so i gave up, but then today i thought i'd have a final search on google, and i have found a solution

I was already aware that the input was "too much" as in, if there was some way to put a volume control in between the dock and the HU then the problem would be solved, but there was no way i could thi nk of making that happen, but after coming across this thread http://forums.ilounge.com/windows-ipod-discussion-problems/119772-distorted-sound-fix-good.html problem solved! after dropping each file to 85db, there is no clipping on any of my songs! although this isn't "solving" the problem, it is bypassing it, because obviously if someone else puts their ipod in it will still clip, but i'm happy with this method

Thanks for all your help and input