[jrabone]

One thing that is alluded to but perhaps not explored fully is the use of noise-shaping dither techniques which rely on pushing the noise out into the ultrasonic region. Xiph mentions it in the context of 16 bit resolution, but I believe it interacts with the discussion of 192 kHz sampling.

Significant noise power at ultrasonic frequencies (or even a skewing towards higher audible frequencies) represents a problem for tweeters & amplifiers both in terms of the intermodulation distortion mentioned in Xiph's article and in terms of power dissipation at the business end. IIRC Dell and VLC are having a falling-out because VLC's soft clipping is damaging the speakers in certain Dell laptops.

[mbell]

> Significant noise power at ultrasonic frequencies (or even a skewing towards higher audible frequencies) represents a problem for tweeters & amplifiers both in terms of the intermodulation distortion mentioned in the article and in terms of power dissipation at the business end. IIRC Dell and VLC are having a falling-out because VLC's soft clipping is damaging the speakers in certain Dell laptops.

Dell probably didn't bother putting an analog reconstruction filter on their DACs, assuming they used an average Realtek codec the digital filter in the DAC has a minimum cutoff point around 28khz but could be higher when operating with higher sampling rates. They probably also sent the signal into a filterless class D amp to drive the output. Those two things together add up to a lot of ultrasonic crap in the signal.

[sp332]

Here's the discussion on that Dell issue. https://news.ycombinator.com/item?id=7205759 "Simply said, the sound card outputs at max 10W, and the speakers only can take 6W in, and neither their BIOS or drivers block this."

[jrabone]

That's actually good design - the intention being that any clipping can only be due to software (which you can fix), not underpowered amplification hardware (which you can't).

[sp332]

It's certainly a software issue, but the fault is in the BIOS, not VLC.

[PavlovsCat]

"Installing VLC Media Player voids your [Dell] speaker warranty", 64 days ago: https://news.ycombinator.com/item?id=7205759

[ferongr]

VLC doesn't soft-clip to my knowledge.

[jrabone]

From previous discussion, quoting 'jbk'

VLC allows amplification of the INPUT above the sound that was decoded. This is just like replay gain, broken codecs, badly recorded files or post-amplification and can lead to saturation. ... snip ... At worse, this will reduce the dynamics and saturate a lot, but this is not going to break your hardware.

Except it can - because the saturation skews the power distribution towards higher frequencies which weren't designed for. This is very, very well known - it's the reason why one always chooses an amplifier with higher output rating than the speakers, often by a factor of two. It's counter-intuitive but driving a low-rated amp into saturation can overheat and destroy tweeters. (Guitar amps get away with it by having massive voice coils on a speaker which will only ever need to reproduce up to about 5kHz.)

[ferongr]

I was talking about soft-clipping, not clipping in general. I know that the volume control in VLC can increase the gain of the signal beyond full scale.