Hi RawwrBag,The tech at the dealership couldn’t do anything about it. All software was up to date. He said the notes from the work order would be forwarded to GM, but to not expect a fix and to use an aux cable as a permanent workaround.
The tech was a guitarist, and could clearly hear the distortion. We tried it out on his Android phone on a few Foo Fighters songs, and he described the effect: “that chord is shifting between A and A flat”.
Is there any way to contact GM directly about this?
@Fulgerite: Bluetooth and USB both have the issue. A 3.5mm aux cable does not.
Thanks for the response on behalf of Chevrolet. Would you like all of us to send a PM with our data and experiences or do you want to work with one person as a representative of the group? I just happen to be traveling this week and received a Malibu as my rental car. I am experiencing the exact same issue described here in that car as well to this definitely appears to be Mylink related rather than volt-specific.Hi RawwrBag,
We always appreciate both the positive and constructive feedback, and can assure you that we do take this feedback quite seriously. With your permission, I'd like to feed this back to our engineers and design team, but prior to doing that, we'd appreciate any additional info you'd be willing to share. If you're comfortable, please private message us with your VIN, your name, the make/model of your Volt and any additional thoughts related to your vehicle's audio playback concerns. Thank you for taking the time to share some additional thoughts with us.
Chevrolet Customer Care
Just thought I would add my 2 cents in case anyone was interested. I can confirm that this is DEFINITELY NOT limited to volts. I just bought a brand new 2015 Camaro (with Boston audio package), and am experiencing this exact issue when using Bluetooth to stream music. Radio and XM seem to be unaffected, and I have not had a chance to try out a 3.5mm yet. I am currently running an iPhone 6 Plus with iOS 8.4....this definitely appears to be Mylink related rather than volt-specific
I am a big fan of GM, but this is clearly not a desired "characteristic" of ANY audio infotainment system, guys. As far as MyLink is concerned, this is a critical bug that renders most of the system pretty worthless. I am sincerely hoping that there is a dev team SOMEWHERE with this on their board. When we were sold these vehicles, we were eagerly pitched a system that could integrate with our phones/devices via a wireless connection. At the very least I think we deserve an explanation on what is going wrong with our cars, and why exactly the decision was made to not fix this glaring problem (if this is indeed the case)....GM have now confirmed (the pitch oscillation) is a "characteristic" and not something that Panasonic considers to be a problem.
For Gen 1 readers new to this thread, you may have wondered why music streamed via Bluetooth from a mobile device sounds "out-of-tune" or distorted in terms of pitch. The problem is that Bluetooth streams don't playback accurately, but are subject to pitch "bending", i.e., they constantly oscillate slightly sharp and flat. The problem is also present to some degree using a USB cable to connect the mobile device. The problem is NOT present when the device is connected to the Aux input (3.5mm plug). It's also not present in music stored on a USB thumb drive. Note: the problem is not limited to the Volt, but has been reported in MyLink installations across the product line.UPDATE:
I finally had a little time to play around a bit with my wave generator. Checked all frequencies between 400Hz and 1200Hz (with a step size of about 50Hz). As stated above, this was a 2015 Camaro using an iPhone 6 Plus running 8.4. I realize that this is a Volt forum, but I thought I would post my findings here as well in case anyone is curious.
Bluetooth: Pitch is clearly oscillating up and down about 10-15Hz each second. This is especially apparent at or above 1000Hz. Oscillations are less noticeable but definitely still present all the way down to 400Hz. Turning the phone's WIFI off does not seem to have any effect. There seems to be an inconsistent delay (about 10-30 seconds) between when the tone begins playing and when the pitch actually begins to vary. Turning the system on and off does not seem to have any effect.
USB: Unable to create any noticeable oscillation. I could have sworn I was hearing it when playing music earlier today, however I will concede that I must have imagined this. In my specific case, using the USB connection seems to be a viable work-around until the defect is identified and corrected.
Thanks for the report! It's good to know the problem was fixed in Gen 2. For Gen 1 owners, the work-around is to either use an aux cable or load the music onto a USB thumb drive.Thanks for the very thorough analysis. Having moved from a Gen 1 (2015) to Gen 2 (2017) Volt, and having experienced this in my Gen 1, I can confirm:
1. The problem does not exist in the Gen 2
2. The problem was with all iPhones through the iPhone 8. Have not tested/used Android.
3. The only fix I've discovered is to move to another car. I have seen this issue on all Chevy cars with MyLink 2015 and earlier. This includes Malibu and Cruze models. Chevy appears to have significantly updated the infotainment systems begining with the 2016 MY.
Thanks for the report. Perhaps the 2013MY wasn’t affected?...I first spent about 45 minutes in the car, making back to back comparisons of the same tracks via BT and USB. Tracks varied from fast to slow, country to classical. EQ on iPhone 6 was flat, same tone settings on both inputs on car system. I could not hear the pitch deviation as outlined in the thread, and finally quit the comparison test.
The next day I downloaded a signal generator app and spent another 1/2 hr playing tones from 300 - 1200 cps with the same result - as best as I could determine I heard no pitch deviation. I would like to have put a scope on the output, but had sold my equipment when we moved the last time....
Wow! That is far more than just annoying - it would be impossible to listen to any music with that kind of deviation. I experienced nothing remotely like that while I was playing with the system. I think I will download Cleartune and play with this some more.
I’ll be interested in your test results. One suggestion: play a given tone for about a minute before switching. It seems that the error is induced after about 30 seconds of ‘normal’ streaming. A pretty good description can be found in this thread’s post #18, from July '14:Wow! That is far more than just annoying - it would be impossible to listen to any music with that kind of deviation. I experienced nothing remotely like that while I was playing with the system. I think I will download Cleartune and play with this some more.
Don:I’ll be interested in your test results. One suggestion: play a given tone for about a minute before switching. It seems that the error is induced after about 30 seconds of ‘normal’ streaming. A pretty good description can be found in this thread’s post #18, from July '14: