Live data from Hacker News

AirPods get stuck in low-quality 16 kHz audio mode when starting a VM

jeffgeerling.com

131–140 of 170 posts

Re: AirPods get stuck in low-quality 16 kHz audio mode when starting a VM

#131
post #10

Happens to my Bose QC35s quite often. Part of the issue is that the mic cannot be enabled when full quality audio is active. I guess this is a bandwidth limitation. My issue stems from pulse audio saying that high quality mode is not available though. Common problem though. Not exclusive to AirPods.

Meh, its not really a bandwidth limitation on modern Bluetooth devices, only that it negotiates a different Bluetooth profle. The high quality stereo audio mode (A2DP) has no support for microphones in the spec and is usually highly buffered, so it switches over to the headset profile (HSP). This mode is designed for compatibility all the way back to your old Motorola Razr flip phone, so it doesn't exactly have the h…

>(A2DP) [...] is usually highly buffered, so it switches over to the headset profile (HSP).

Thanks for this information. That explains why it is reasonable to drop the audio quality.

Re: AirPods get stuck in low-quality 16 kHz audio mode when starting a VM

#132
post #66

Earlier quoted context omitted.

Guess what the number one car infotainment complaint is... I don't have a public source, but for some vehicles bluetooth problems are the number one complain OVERALL.

There's also the problem of wireless tech UX being difficult in general. For example, people want the experience of turning on their devices and auto-pairing with their other devices. But headphones, for example, don't have much of a UI to manage this. There's the hellish scenario of everyone in your car hearing the conversation you thought you were having on your back patio in private just because you walked too clo…

Imagine if you connected this way: 1. turn on peripheral, 2. choose it from a UI on the device and get connected. That is easy, it is the auto-pairing bullshit that forces the software to guess using a heuristic, which guarantees it will get it wrong a non-zero amount of the time. Now that we all have N devices it will get it right 1 out of N times.

This is just terrible UX, the choice reality gave us was between auto-pairing that is frequently wrong or having to make one UI interaction. Guess which one they chose?

It is a valuable lesson, never let designers hand-wave away reality because they have a delusional vision of a magic device. Acknowledge reality and design around it instead or you will build crap.

Re: AirPods get stuck in low-quality 16 kHz audio mode when starting a VM

#133
post #115

Earlier quoted context omitted.

I absolutely hate the terrible audio when using my Jabra Elite Active 65t to talk over VoIP. It should be crystal clear HD audio, but I have to listen to scratchy voices. I have trouble processing audio, so it makes calls really difficult. I've started resorting to cheap earbuds to hear people for really critical calls like interviews.

What’s the reasoning on the cheap earbuds

No Bluetooth, no VoIP, just analog.

Re: AirPods get stuck in low-quality 16 kHz audio mode when starting a VM

#134
post #17

Did weird stuff like this happen with wired headphones?

It’s definitely a Bluetooth audio thing. I can hear mine shift into a lower quality audio when I use them for conference calls. (There’s a limited amount of bandwidth and it has to make room for bidirectional audio.)

As someone else pointed out it is not actually bandwidth problem. Reason behind this is that high quality audio streaming profile A2DP is one-way only and once mic is needed, profile is changed to bidirectional but low quality HSP. My workaround for conference calls is to use my MacBook's internal microphone instead of one of my Bluetooth headset.

Re: AirPods get stuck in low-quality 16 kHz audio mode when starting a VM

#135

Earlier quoted context omitted.

It has 20 years of organic growth and includes a lot of lessons learned from the initial underspecification. Lots of profiles were specified but never used (video delivery, over bluetooth, anyone?). Many were not fully thought through and had to be revised (often in nasty ways to remain backwards-compatible). Sadly backwards compatibility makes it worse and worse every year. If you go and write a stack that complies…

Are you able to tell me if the codec situation (for A2DP) is as big a mess as it seems? One manufacturer is flat out lying about apt-X support, but it seems that if you want to support it you need DRM everywhere and hefty payments.

Worse

Re: AirPods get stuck in low-quality 16 kHz audio mode when starting a VM

#136

Earlier quoted context omitted.

It has 20 years of organic growth and includes a lot of lessons learned from the initial underspecification. Lots of profiles were specified but never used (video delivery, over bluetooth, anyone?). Many were not fully thought through and had to be revised (often in nasty ways to remain backwards-compatible). Sadly backwards compatibility makes it worse and worse every year. If you go and write a stack that complies…

If BT 4 is better, shouldn't BT 4 devices like the AirPods connected to BT 4 devices like modern Mac computers not have these types of weird problems? :/

No. Bt 4 adds LE but audio doesn't go over LE yet so no improvement yet

Re: AirPods get stuck in low-quality 16 kHz audio mode when starting a VM

#137

Honestly coreaudiod is a hot mess. Every time I plug in a usb audio adapter it puts balance at 100% left channel and max volume. killall coreaudiod fixes it. I miss when Macs worked reliably.

I’ve run into this issue since owning my first Mac, circa 7 years ago. So while I don’t agree with your over generalization, I do agree that this is very bad and should be fixed once and for all!

Re: AirPods get stuck in low-quality 16 kHz audio mode when starting a VM

#138

Earlier quoted context omitted.

You can cut the data lines in a cable and it should solve some of the issues with unwanted behaviour. The album art and track progress I don't really care about (eyes on the road!) but via Bluetooth that's AVRCP and there's a stack of standards for people to butcher there, too.

I was wiring in a charge only USB port in my car today and found out that cutting the data lines limits the charge rate to a uselessly low rate. You need to tie the data lines together to put it in usb bc1.2 mode. Or 2.7 v on each line for 2.4 a iPhone charge or other modes. It isn’t simple. Simpler than Bluetooth, but not “hook up ground and 5v” simple.

There's a fast charge dongle for this. Portapow makes one.

Re: AirPods get stuck in low-quality 16 kHz audio mode when starting a VM

#139
post #107
post #74

Earlier quoted context omitted.

I wouldn't be surprised, but my frustration is a poor implementation or unintuitive implementation. Quite a few cars go into USB-mode as soon as you attach a phone--almost 100% of the time they just want to charge their phone and already have things set up via Bluetooth or the radio. iPhones won't let you play through the phone if you have an attached audio device. Some cars seem to be able to do album art and track…

A few weeks ago, I asked for a compact rental car, but was given a 2018 or 2019 Chevrolet Equinox. It had an USB-A as well as an USB-C port. I already had Android Auto on my Pixel, so I was up and running in a few instants. I did NOT miss setting up Bluetooth or Ford's Sync thingie. Maybe there's hope at the end of the tunnel.

My Ford has Android Auto and CarPlay. And it never messes up Bluetooth if I don’t plug in ‍️. My WRX is kind of a hot mess. Plugging in never worked. It does fine with Bluetooth, usually, but when it gets confused it really shits the bed. Does not have AA or CarPlay. Is a newer car.

Re: AirPods get stuck in low-quality 16 kHz audio mode when starting a VM

#140

I have tried to read the BlueTooth specs a few times, never really getting anywhere, and am amazed that it all (mostly) works given the immense complexity in those standards[1]. Thus I'm not surprised that bugs like this can occur. [1] The BT5 core spec is freely downloadable. It is a 25MB PDF with over 2800 pages. That's just the core, there are other specifications that layer on top of it.

https://github.com/torvalds/linux/tree/master/drivers/blueto... The Linux source for it is even less approachable.

Well, those are mostly just vendor specific drivers.

Actual Bluetooth kernel code can be found here: https://github.com/torvalds/linux/tree/master/net/bluetooth

IMO it is quite well organised and readable.

Post reply on HN