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Installing VLC Media Player voids your speaker warranty

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Re: Installing VLC Media Player voids your speaker warranty

#91

Post by TeMPOraL »

byuu wrote: post #80
TeMPOraL wrote: post #63

Earlier quoted context omitted.

> Can you imagine every piece of software checking for every piece of esoteric hardware and having some special behavior? This is what MS Office does. A Microsoft engineer told me once that because many printers lie to the OS about their capabilities, they built a giant lookup table into the Office, that basically consists of "if printer model X, vendor Y and firmware Z, then don't trust it about the fonts onboard, r…

I remember back in the day doing DirectDraw/Direct3D programming, I had to have lots of "if video card type == x, then ignore these capabilities and do this other thing instead" hacks. A much bigger issue back then when we had more than three video card manufacturers. (it's still a minor issue today ... nVidia cards tend to be way more permissive about OpenGL calls than AMD cards. But I can afford two discrete cards…

Or, you could crowdsource an open-source abstraction layer; this would level the playing field again.

Re: Installing VLC Media Player voids your speaker warranty

#93

Post by TylerE »

maxerickson wrote: post #16
Aardwolf wrote: post #8

Shouldn't instead Dell make the speakers not be able to get physically damanged by software?

It would probably either cost more or the speakers would have a lower peak volume. I don't think it is a wild compromise to make some assumptions about the sounds people will play through the speakers (and it's not like a spec relating the max energy/time is going to help most shoppers).

> (and it's not like a spec relating the max energy/time is going to help most shoppers

Actually, speakers are speced in terms of RMS wattage...which is exactly that.

Re: Installing VLC Media Player voids your speaker warranty

#94

Post by amenod »

guard-of-terra wrote: post #76
TeMPOraL wrote: post #73

Earlier quoted context omitted.

> I'm no expert but maybe it's actually possible to create speaker that doesn't go bad. Of course it is, but nobody wants to do that; it's not profitable. * sigh * . I sometimes wonder how difficult would it be to create, say, a brand of kettles with lifetime warranty, designed to last 50+ years instead of 50+ weeks the ones we have do. How hard would it be to sell them and to what ends would the competition go to st…

I never had either failing speaker or failing* kettle in my life so it's hard for me to say anything. Maybe there just so much you can get from laptop speakers so it makes sense to cap their power hard? * Some no loger turn off automatically, tho

Kettle: I had one with the same problem. That's a terminal failure to me...

Re: Installing VLC Media Player voids your speaker warranty

#95

Post by lutusp »

KaiserPro wrote: post #79
Ma8ee wrote: post #18

Earlier quoted context omitted.

Speakers are built to be able to withstand short peaks with high power to reflect the dynamic in the music or your movie. This is what is abused to be able to play loud sounds continuously. You could take the possibility to do that away, but then you would of course also remove some of the dynamics out of the music. But of course, the people that burn their speakers this way don't care about dynamics or evidently abo…

Thats what limiters are for. The whole point of hard clipping is that +256 or -256 (or the 16bit equivalent) is below the point at which your speakers, amps, cabling or anything else starts to melt. Speakers/amps should have DC protection builtin.

> Thats what limiters are for.

Limiters cannot either distinguish or protect against the technical difference between a sine wave and a square wave:

http://i.imgur.com/oE5NFZ9.png

The red trace is a normal audio signal that doesn't exceed the dynamic range of the amplifier. The green trace is an example of the kind of signal one gets by turning the volume up way above normal.

In a hypothetical speaker of one ohm and a peak voltage of one volt, the red trace has a time-averaged power level of 1/2 watt. The green trace has a power level of one watt -- twice as high, and possibly too high for the speakers to tolerate.

> Speakers/amps should have DC protection builtin.

This example should show that this isn't possible without taking the temperature of the speaker's activation coil -- and even that might not work.

Re: Installing VLC Media Player voids your speaker warranty

#96

Post by tmzt »

mansr wrote: post #32

When the Samsung ARM Chromebook came out, people quickly found that careless tinkering with alsamixer caused the speakers to overheat and melt the case as a result of being driven with a high DC current. A driver update blocked the control causing the damaging signal routing.

Do you know what kernel version or distribution fixed that? I've avoided installing a native distribution for that reason.

Re: Installing VLC Media Player voids your speaker warranty

#97

Post by coldtea »

astral303 wrote: post #74
guard-of-terra wrote: post #52

Earlier quoted context omitted.

Nobody prevents the manufacturing to put some electronic bits before the speakers to cap the maximum power. Even better, teach the sound card to do that.

A square wave has twice the power of a sine wave of identical amplitude. This is why distorting the amplifiers (especially digital clipping) is so much worse for speakers than overpowering the speakers. This is a very well known fact in audio circles. Playing metal at full volume is not as damaging as playing anything intensely digitally clipped at full volume. Yes, Dell is putting on shitty speakers on their laptops…

>but VLC should be amplifying the output using level-limiting (hard-limiting), which would effectively bring all the quiet parts to be just as loud as the loud parts, instead of just digitally clipping the output.

That's compression, not hard-limiting. Hard limiting would leave the quiet parts quiet relative to the loud parts. It would only crush them if they were not enough dynamics in the first place.

Re: Installing VLC Media Player voids your speaker warranty

#98

Post by sklivvz1971 »

In professional audio (and even amateur radio) one always puts speakers rated for 1.5x the nominal output of the amp. At least. This makes sure that whatever the input in the amp, the speakers are safe.

If Dell doesn't build audio properly, how can they blame the users? They really have some gut...

Re: Installing VLC Media Player voids your speaker warranty

#99

Post by malandrew »

astral303 wrote: post #74
guard-of-terra wrote: post #52

Earlier quoted context omitted.

Nobody prevents the manufacturing to put some electronic bits before the speakers to cap the maximum power. Even better, teach the sound card to do that.

A square wave has twice the power of a sine wave of identical amplitude. This is why distorting the amplifiers (especially digital clipping) is so much worse for speakers than overpowering the speakers. This is a very well known fact in audio circles. Playing metal at full volume is not as damaging as playing anything intensely digitally clipped at full volume. Yes, Dell is putting on shitty speakers on their laptops…

Most metal released these days is digitally clipped. Even classic old 80s "remastered" records are digitally clipping all over the place. The loudness wars has ruined most metal through remasters.

Re: Installing VLC Media Player voids your speaker warranty

#100

Post by weland »

ferongr wrote: post #56
guard-of-terra wrote: post #52

Earlier quoted context omitted.

Nobody prevents the manufacturing to put some electronic bits before the speakers to cap the maximum power. Even better, teach the sound card to do that.

Analog limiter ICs (that I know of) limit the signal according to input voltage, something that does not catch this issue. Furthermore, limiting power at the audio codec level would require for the codec to have that feature and I don't know of audio codecs with that capability.

Cheap shit. Seriously, cheap shit. There are several ways to solve this, all of which boil down to "use more chips" or "use better speakers", thus increasing the price of already incredibly shitty speakers. Source: I'm involved in designing consumer electronic products and the only corners that don't get cut are those that, if cut, result in certifications not being granted and therefore in products you're unable to sell. Everyone, Apple included, does it.

The easiest way to solve this is use stronger materials for the speaker construction. This does, yes, affect the quality of the sound, which is already somewhere between catastrophic and abysmal on a laptop. The frequency response is likely to be worse, on a set of speakers that already has a frequency response that makes them quite useless for music.

You can also do it in electronics, as measuring the power delivered to speakers is not exactly rocket science. The response time wouldn't be great, but it's continuously shredding the speakers with square signals that damages them, not a couple of pulses every once in a while. You can also detect heavy slopes. You can even detect heavy slopes in software.

But no, seriously, this is a problem that can be solved. The mere fact that a lot of manufacturers manage to come up with speakers that don't break should be a testimony to this. I have (granted, desktop) speakers that have gone through a decade of heavy metal, grindcore and fucking SIDs and MODs, on bad ALSA drivers that I could barely get to work for years. They're fine. This is just Dell selling cheap shit.

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