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Comment by madaxe_again | Hacker News Reader

The audio balance on Apple computers changes randomly, and has done so for at least a decade.

https://apple.stackexchange.com/questions/79384/audio-balanc...

Yep, I’ve very much discovered and confirmed this behaviour independently, I was so shocked to learn that it was a known issue.

I know it’s silly but it helped me with imposter syndrome to see such a major OS that prides itself on seamless “it just works” experiences tolerate bugs like this.

That and the fact if you airplay a movie to Apple TV it thinks you want it to cast over the top of it with random advert videos in your web browser, so you can’t watch and browse.

We’re all human I guess ;)

But a lot of those bugs are basic functionalities, it is just that they are not the path Apple wants you to take.

For years now, and across iphone models and iOS versions, my iphone randomizes the artwork of the mp3s in the music app (ie display the wrong album cover). I see people complaining about that in forums but I guess if you are not using Apple Music they don't care.

I don't seem to be able to copy files from my iphone onto a windows desktop. Tried several cables, the transfer fails after a few GB. I guess if you are not syncing your files through iCloud they don't care.

A bug recently corrupted the iphone mail app. It wouldn't sync mails anymore, in fact would display old mails from the wrong account (I have multiple setup). I only fixed it by deleting the accounts and recreating them. That's using ActiveSync. But I guess if you don't use an apple email they don't care.

Another bug on my ipad. The USB-C DAC often fails to be recognised. Tried several DAC. I thought it was a hardware problem (usb port damaged), except that few hardware problems are resolved by rebooting. But if you don't use apple wireless headphones they don't care.

These are basic functionalities, but not using the main path which happens to be the most profitable to Apple. Apple's reputation for quality is inconsistent with my experience of their products.

Whether you will enjoy using Apple products depends significantly on whether you are willing to go down and only down the One Apple Way(tm).

It has nothing to do with profitability. The problem is there are too many devices, protocols and applications so it's impossible to test them all. You'll have exactly the same type of issues on a Windows or Linux based system. Microsoft also doesn't seem to care anymore and Linux distributions are not even tested for desktop use.

If anything, profitability of chip makers cheaping out on USB implementations is a bigger problem.

Does Apple have a public bug tracker?

No. They have a black hole you can toss your bug reports into, and they’ll swear up and down that past the event horizon they’ll see it, but you more likely than not will never hear about it again.

Following the link, and a few more, describes at as changing "when volume buttons are pressed during high CPU load". That is perhaps random-seeming, but also way different from actually being reandom.

I have never used a (modern) Mac long enough to listen to audio, so I have no experience with this I just thought it sounded odd.

Now having learned that, I really (really) wonder how such a bug can happen, and how it can stay ignored for so long by the always-ranted-about masters of vertically integrated luxury computers. More the former, though.

It sounds almost as if there already is software somewhere that is doing something to maintain the proper balance (perhaps due to bugs in the hardware), and then that something becomes CPU-starved and/or interrupted when the volume changes, and doesn't resume properly. This is a wild guess straight outta ... Hampton, I have no clue about Mac hardware or macOS internals. Fun to think about, though!

I hope they fix it for real, soon!

> Now having learned that, I really (really) wonder how such a bug can happen, and how it can stay ignored for so long by the always-ranted-about masters of vertically integrated luxury computers. More the former, though.

My first guess was that "volume up" is actually "increase volume on left channel" and "increase volume on right channel"

And when there's high CPU load, one of those commands gets lost or ignored for some reason.

That's an even simpler (=better, often) theory! Thanks!

And they can't synchronize this?

Normally the solution to this is to have a pair of parameters, pan and gain and compute the discrete channel gains from those two parameters. That way there's no synchronization and you can handle changes to those parameters independently.

It sounds like they have inverted the relationship between what is displayed to the users and what is used by the machine.

There are worse bugs that happen under high CPU load - I reported that you can interact with applications behind the hibernate Lock Screen… 9 years ago. You still can.

I've been using macs since the 90s for "serious amateur" music production, and I listen to music while working on an MBP daily, both via the headphone jack and via a USB audio interface, and I've never encountered that. Is there no idea what triggers it?

Quickly changing the system volume while the system is under heavy CPU load, plus chance.

That's indeed something I've never done. So the culprit is that the volume knob sends multiple messages and they get lost or something?

FWIW, I just ran the following stress test for a bit in VSCode, and then mashed the Vol +/- buttons on an M1, and noticed that the volume toggle started to lag, but I didn't notice any balance drift. Is this something that would be reflected in the slider, or is it auditory-only?

+function() { while (1) { for (var i = 0; i < 1000000000000000; i++) { console.log(i); for (var j = 0; j < 1000000000000000; j++) { console.log(j); } } console.log('herewegoagain'); } }();

In my experience the slider definitely moves. You can see it in real time with the settings page open

I use my Macs for audio a lot, including with headphones, and have never experienced this in 20 years.

This is one of those things that make you question reality somewhat as I know, from seeing countless videos and having some familiarity with the topic, that macs dominate desktop music production - I've never seen a producer or a DJ using windows, ever. This is apparently because the USB audio stack on mac is so streamlined that the buffering is minimal, i.e. you can basically apply realtime audio effects and mix 'live' using a USB output sink, i.e. that you can DJ with it.

Now apparently there's a game-breaking bug? For 10 years? And it's a really really big deal?

Hmm.

well this is seemingly only when adjusting volume on the Mac itself. The Apogee plugged into my Mac has its own volume control, that doesn't suffer from this drift.

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