Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

24/192 Music Downloads Are Very Silly Indeed (2012)

xiph.org

Post reply on HN
Print view View original

91–100 of 445 posts

Re: 24/192 Music Downloads Are Very Silly Indeed (2012)

#91

Post by combatentropy »

RachelF wrote: post #69

To be replaced soon by "4k video is very silly indeed" If you look at the angular resolution of the eye, unless you are sitting very close to the screen, you can't resolve 4k video.

Yes, I've measured my eyes' resolution to be about 60 pixels per degree. I made a black-and-white grid and set it as my desktop picture, with a one-to-one magnification. Then I backed away until I could not discern the pixels. There's even a moire effect, like with cameras, as I reached my threshold. Then I used trigonometry to calculate my angle of view.

Most living-room TVs are probably placed at a 15- to 25-degree angle of view. 1920x1080 is enough for up to a 32-degree horizontal angle of view, which is 7 feet away from a TV with a 55" diagonal, for example. I will say, however, that movie theaters look a little better with 4K, since 30 degrees is supposed to be the back row, and the front row might be 60 or so.

Re: 24/192 Music Downloads Are Very Silly Indeed (2012)

#92

Post by enneff »

zkSNARK wrote: post #35
sp332 wrote: post #22

Earlier quoted context omitted.

But if you're filtering out ultrasonics, then you've guaranteed that the extra samples will be wasted. There won't be any difference in the reconstructed signal at all.

As an engineer, those extra samples are never wasted, and as a listener, I could care less about the "wasted space." Drive space is meaningless at this point. When I buy a piece of audio, give me the highest quality available and I will make my own decisions regarding the frequency I want to listen to it at. The reasons behind not giving the user the highest quality possible all sound like a misguided excuse to preve…

> as a listener, I could care less about the "wasted space."

In general, bandwidth is more of a concern than disk space. Most media people consume is never stored on the local device.

Re: 24/192 Music Downloads Are Very Silly Indeed (2012)

#93

Post by gothroach »

acchow wrote: post #78
hamandcheese wrote: post #12

Earlier quoted context omitted.

24/192 can capture audio well beyond what we can hear. These sounds can, though, lead to distortion that is within our hearing range, depending on the equipment used. Therefore, rather than just being useless extra data, it can be actively harmful to the listening experience.

But weren't those "outside our hearing range sounds that can distort our hearing range" present in real life when the recording was made? So I would have heard the distortions had I been there in real life?

The distortions he's talking about would be introduced during playback by DAC, signal processing, speakers, or amplification.

Re: 24/192 Music Downloads Are Very Silly Indeed (2012)

#94

Post by lgunsch »

Veratyr wrote: post #61
TazeTSchnitzel wrote: post #46

Earlier quoted context omitted.

IIRC, I think the article's point about maximum volume was about how you'd need to turn the volume up to deafening levels before the small differences would be noticeable.

It doesn't seem to say anything like that. Looking at it again, I see this: > It is also worth mentioning that increasing the bit depth of the audio representation from 16 to 24 bits does not increase the perceptible resolution or 'fineness' of the audio. It only increases the dynamic range, the range between the softest possible and the loudest possible sound, by lowering the noise floor. However, a 16-bit noise flo…

The video linked in the top-most comment will beautifully answer your questions. It's also on YouTube.

You can think of it as in the sampling rate provides a mathimatical solution to the waveform - it's simply 100% accurate all the time. The bit depth adds extra "buckets" to divide the volumes into . If you have 2 bits, you then have volume levels 0, 1, 2, 3.

Re: 24/192 Music Downloads Are Very Silly Indeed (2012)

#95

Post by peatmoss »

tzs wrote: post #83

What about for non-humans? Consider a dog that lives with a musician who plays, for example, trumpet. The musician plays the trumpet at home to practice, and also records his practices to review. A trumpet produces significant acoustic energy out to about 100 KHz [1]. When the musician plays live the dog hears a rich musical instrument. When the musician plays back his recordings, half the frequency range that the do…

What about transhumans? I'm looking forward to my HiFi Cochleatron 9000(tm) when my hearing starts to go.

Then I'll be mighty glad we made all these high-res recordings.

Re: 24/192 Music Downloads Are Very Silly Indeed (2012)

#96

Post by rcthompson »

acchow wrote: post #78
hamandcheese wrote: post #12

Earlier quoted context omitted.

24/192 can capture audio well beyond what we can hear. These sounds can, though, lead to distortion that is within our hearing range, depending on the equipment used. Therefore, rather than just being useless extra data, it can be actively harmful to the listening experience.

But weren't those "outside our hearing range sounds that can distort our hearing range" present in real life when the recording was made? So I would have heard the distortions had I been there in real life?

The distortions are not present in the source. They occur because the speaker is a physical device subject to physical limitations and can't perfectly reproduce the waveform. In the process of trying to reproduce the ultrasonic signal, the speaker can produce audible distortions. If the ultrasonic signal is not there to begin with, then it can't possibly cause distortion.

Re: 24/192 Music Downloads Are Very Silly Indeed (2012)

#97

Post by rconti »

jaquers wrote: post #85
rconti wrote: post #74

Off topic, but I've noticed in the gym, sometimes the music playing from the instructor's iPhone through one of those cheap Ion Block Rocker bluetooth speakers (big boxy one, looks like a guitar amp) has very very noticeable pitch sag in various parts of various songs. It's via bluetooth, and the source is Pandora. I even googled Pandora and pitch change, and found some forums with folks discussing bluetooth causing…

At my greatest aspiration, I'm no more than a casual music listener - however I am very conscious of pitch. On more than one occasion, I've noticed that a song I'm familiar with seems off pitch, as in lower or higher key than I think of it in my head - and I seem to notice that particularly around shitty speakers or bluetooth or some combination of the two. Glad to know I'm not crazy :) To your point, I would lean to…

I use spotify as well. And what I describe is a sag for 5 or 10 or 15 seconds, not just a song that's playing too slowly. it's really weird.

Re: 24/192 Music Downloads Are Very Silly Indeed (2012)

#98

Post by IgorPartola »

zkSNARK wrote: post #35
sp332 wrote: post #22

Earlier quoted context omitted.

But if you're filtering out ultrasonics, then you've guaranteed that the extra samples will be wasted. There won't be any difference in the reconstructed signal at all.

As an engineer, those extra samples are never wasted, and as a listener, I could care less about the "wasted space." Drive space is meaningless at this point. When I buy a piece of audio, give me the highest quality available and I will make my own decisions regarding the frequency I want to listen to it at. The reasons behind not giving the user the highest quality possible all sound like a misguided excuse to preve…

So 192/1024? 1024/4M? 1G/1T? Like is there a practical limit for you when you say "highest quality possible"?

Re: 24/192 Music Downloads Are Very Silly Indeed (2012)

#99

Post by AceJohnny2 »

jahnu wrote: post #18

I've said it before, this video demo is one of the very best I've ever seen. https://xiph.org/video/vid2.shtml So well prepared, so well presented, so little that could be removed without ruining it. I aspire to do such good demos but always fall so short.

Monty Montgomery, the author, hangs around here as id=xiphmont :)

Re: 24/192 Music Downloads Are Very Silly Indeed (2012)

#100

Post by gsteinb88 »

Veratyr wrote: post #30

Perhaps this is a silly question but the explanations mostly make perfect sense to me but in the case of sample rate, what happens when two waves with very different frequencies overlap? Say I've got an 18kHz wave and a 9kHz wave and the 9kHz wave is ever so slightly out of phase. Then imagine there are 10 different waves under 20kHz all interfering with each other in different wages. Is it still possible to reproduc…

So long as all frequencies you're trying to represent are below the Nyquist frequency, there's still only one band-limited reconstruction of the samples. So yes, it's still possible to reproduce everything accurately so long as all of the individual frequencies (no matter their relationships) fall below 1/2 the sample rate.
Post reply on HN