Hacker News Reader

Comment by capitainenemo | Hacker News Reader

One of the first chromebooks would melt and burn if you fired up alsamixer and tried toggling a few of the toggles. I encountered this myself fiddling with the audio settings and ended up with magic smoke and melting plastic before I quickly powered it off.

https://marcin.juszkiewicz.com.pl/2012/12/10/how-to-fry-spea... https://groups.google.com/g/comp.os.linux.advocacy/c/QslNrtx...

(note it doesn't actually require installing another distro - alsamixer was available in the base chromeos install)

View on HN

I wonder if something like this is what happened to my 2013 chromebook pixel. About a month after the warranty ran out, the audio quality from the left speaker rapidly degraded to distorted crap over the course of a few days, then stopped forever. Shortly later the same thing happen to the right speaker, and that computer never made a sound again.

Tbh I'm still pretty salty about it.

Not an expert but that sounds like the voice coils overheated. In theory the drivers should prevent you from doing this, but in practice insufficient prevention measures in drivers/DSP combined with running too close to the sun seems to have made it possible to easily do this on some laptops, hence DELL voiding their warranty for people who turn the volume too high in VLC.[1]

[1]: https://www.dell.com/community/Laptops-Wiki/How-Using-the-VL...

Anything you can do with VLC's volume control can be done in the audio file itself - it doesn't touch the hardware at all. This is just dodging responsibility for defective design.

It's true, though frankly most audio files are not distorted to shit, whereas it probably needs to be in order to actually do this. Still, I really think it's on them to protect their hardware. Ideally in hardware, but if they can't even do it in their own drivers it's pretty pathetic.

Sooo they put too weak drivers/too strong amplifier and are trying to blame users on it ?

Sounds like they were letting very low frequencies through to the speakers and/or accidentally producing DC.

I only read the one thread on this, so I'm guessing a lot here, but it sounds like you could patch the <100hz frequency problem in hardware for like $0.50 with a high pass filter soldered in at the speaker?

That thread is a little hard to read, so I don't know if there really is a dc problem. That's a little harder to fix in the speaker cavity.

Yes, you could. A high-pass filter that is able to drive a laptop voice coil down to 100 Hz would probably cost about that much, which is 50x more than the motherboard manufacturer wants to spend.

A high-pass filter in the DSP/driver software is free, sell a million Chromebooks and that's $500k of pure profit from cutting costs. Unless you account for warranty recalls due to buggy drivers, in which case a 0.1% failure rate is enough to make this a bad idea.

A high pass filter is essentially a RC filter in which the resistor part can be the speaker coil, so one only needs two capacitors, one per channel, which would cost a lot less than $0.50 in small quantities (example: Vishay ZSC00BM2211AARL, 220 uF - 10Vdc: €0.14100 in 10 quantity at tme.eu, a lot less in 100 or 500 qty). The problem however is either the amplifier ic which is too powerful, or the speaker itself being too weak to sustain its power. That would be bad design though; one should never assume the signal won't contain certain frequencies; it's good practice to pick a speaker that can sustain at least twice the maximum amplifier power indefinitely, and even more during peaks, regardless of what frequencies are reproduced.

Wow that Google group thread is really something else. So many of those people really need to take a break from having Linux be part of their personality.

> Is this howto useful? I think it is. Cause if you have device broken in some way and you want to get it replaced you can just run it and hope for replacement instead of repair.

Not nice.

Reply on news.ycombinator.com