Popping Sound with USB

Seeing these new posts I thought I would update.

Since I tried the first experiment, I have had only one instance of this noise reccuring and that was while listening to Headphones and using the device to play a game (again Ipod touch 32 g, 4th gen, current OS).

I haven't had the problem in my car through my Pioneer head unit since the first time i tried the fixes on here.

To poly and ego above. Have you tried turning off the device before connecting via usb to your cars headunit? Letting the usb power up the device? I do this every time and it seems to be working fine when I do. I originally turned off the wireless network too, but then I experimented with leaving the wifi on after the problem stopped the first time and it has been fine everysince with wifi turned on, which I find very strange.

I have also disable all notifications on the ipod (push notification, turn off email). This noise seems to be happening if the device is trying to do multiple things

Obviously Apple needs to work out a fix for this bug. I hope my suggestions work for you. If this is happening for Iphone customers I feel sorry for them. with the touch at least I don't really care about email and other notification funcitons while in my car so I don't care if those are off. I just wanna rock out without being annoyed.

Hey, a few weeks ago I had a new Kenwood head unit installed in my 2000 Blazer, and just yesterday I had all the speakers replaced and subs and an amp installed. I have a 4th Gen Ipod Touch, play it through my car head unit with a USB cord, and like everyone else in this thread, have been experiencing plenty of "popping" issues.

I took my truck back to Audio Express today and informed them of the problem. They said that the popping was because I had too much bass going to the front speakers, so they installed bass dampening kit to the two front speakers. While still in the parking lot, I hooked up my Ipod, played a song where I know I would be able to clearly hear any popping sounds...and sure enough, it was still popping like crazy. I happen to catch the the technician who worked on my truck that day, he listened to it, and told me that it was most likely my Ipod that's causing the popping. Be it either corrupted files, damaged hardware, damaged wire, or something else.

Naturally, I came home and did some Googling. After reading through this and many other threads, the one common solution I saw was to turn off ALL push notifications and to close ALL background apps.

I did just that...and sure enough, THE POPPING IS GONE. Even when I played the song I played earlier(Daft Punk's "Rinzler" from the Tron Legacy OST), there was absolutely no popping at all. I also tested this with plugging the USB into an on and off Ipod, and either way, there was no popping.

I probably didn't even need to take my truck in and get those bass dampeners installed, but the technician did say that he heard a little bit of popping even with a CD playing, so at least I got that fixed anyway.

tl;dr version: TURN OFF ALL PUSH NOTIFICATIONS AND CLOSE ALL BACKGROUND APPS. PROBLEM SOLVED.

I have the ipod model MC544LL, iOS 5.1.1 and I've been experiencing the popping noise problem that has been described here on this thread. I've tried the latter solution of "letting the system power up the ipod" and "closed all background apps". Sure enough the popping noise problem went away. Now I've isolated each step, and found that I do not need to let the system power my ipod up from "power off". Simply closing majority of my apps has solved the problem for me! Thanks you all! The noise was driving me NUTS!

Hi;

tried this today and the popping still persists. I have tried playing with the volume in "Music" and that seems to make it less. I also shut down all the background apps, power cycled the phone, and did a sync to iTunes. Very frustrating....

It definately appears to be something to do with the scheduler and clipping packets or doing interrupts.

With so many people experiencing this issue, and the fact that the problem seems to go away when they turn off stuff in the background (additional apps, notifications… etc.). It sure seems like this is a processor issue, like the processor can't keep up and the audio suffers. It would also kind of explain why Apple won't even acknowledge the problem, they don't want to replace their hardware yet. What do you bet this problem is magically solved when the next iPod is released?

I had a smug "genius" flat out tell me the problem doesn't exist, and then refuse to even look at this thread.

Hi;

I think you are right about how the "flow" is not steady and something is clipping or interrupting at a very intermittent way. I am not sure it is the CPU or other chips because it seems others have isolated the combination. Meaning there is no issues with the 3.5mm jack.

I should say I am using a iPhone4 into a Alpine. So, we all have more or less isolated the issues to the use of the USB and it does not matter about the headunit or cable.

What that smells like is something with the OS scheduler for multi-tasks and the driver for the USB interface. it might not have enough buffer or it might have too low priority and some situations start the clipping of packet flow.

It is anyone's guess.... But it should be something Apple labs can investigate and improve either in the software, or if indeed it is a HW issue replace the defective unit with an upgrade sometime.

So after I updated to iOS 5.1.1 and experienced the issue, I did a full reset at that point. Since re-adding all my music and having the iPod work fine, the popping came back (which was when I posted my last comment). Since my last post though, I followed the advice of theooriginal and it seems to have fixed the issue. Now I always let my car system start the iPod and Music app, as opposed to starting a song and then plugging in the USB cable.

As far as running apps and all communications (WiFi, Bluetooth, etc.) I haven't turned off communications or closed all apps; though I rarely keep an app open once I'm done with it. It seems that the issue is when I start a song on the iPod itself, and then plug it in. I usually did this since my stereo takes over control of the iPod, and it's much easier to browse my library on the iPod vs. car stereo. Once the stereo powers up the iPod, I have no issues throughout the day when I continue where I left off, it just seems to be when I plug it in with a song that I've started.

It's very strange, but the popping is definitely gone. I'll also add that I just updated iTunes in and around the same timeframe, but overall it seems that the above advice has been the most consistently successful. I will keep updating this thread if anything changes of course. Hopefully this helps out some others here too.

I just retro fitted a new head unit (RCD-510) to my mkv golf gti 2 days ago. I noticed the crackling and popping like an old record player the very second I played back from my iphone 4s (ios6) through USB. I then tested with 3 different USB cables, my ipad2, friends iphone 4s and ipod touch, and I hear the same static noise in all of them. I have gone through a few automotive forums and they all have the same feedback regarding this issue. My question is, if this problem is experienced by almost everyone, why isn't Apple doing anything about it?

There is a long going thread on this for the iPhone too. I really thought it was HW realted, as it is almost like a bad amplified sound. But, the more I played with my iPhone4, all the tricks of sync, turning the ounds up or down, I am more inclided to think it is a scheduler issue in the iOS working with the flow of the packets accross the transceiver for the USB connector.

It seems widespread accross various headunits, and devices and iOS versions. What seems to work for my is killing off apps and keep in the output of the sounds about 40%.