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24/192 music downloads are silly

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Re: 24/192 music downloads are silly

#301

Post by smosher_ »

The argument is fine for listening to a finished product but those absolutes in the post have some hidden assumptions that don't hold in all real-world scenarios.

That probably sounds like BS. Hear me out.

A common practice for DJs is to use special decks to DJ from iPods, or other digital sources (eg. regular turntables with timecode vinyls operating a PC.) DJing involves playback speed adjustment when there is a BPM difference between the two tracks during a transition. 192kHz is overkill for basic DJing and you'd probably be fine in the vast majority of cases with 48kHz, but if the DJ is a turntablist (scratch etc.), you want all you can get when going from zero to target speed—which is happening constantly. It sounds awful when consumer-grade¹ audio is used. As for the ultrasonics, filtering is the answer in this scenario. It may be quite a good thing for these DJs (and their fans) that Apple is doing this. (I'm not under the impression that this is why they're doing it.)

A lot of the music I listen to uses samples that are played at something like half speed, or tuned down at any rate. I tend to tune samples down by about a fifth myself. Point being: a lot of detail that would otherwise be present with higher samplerate source material goes missing. It doesn't help that tuning down like this dumps a good portion of the low end.

There are also neat ways of exploiting nonlinearities from ultrasonic sources, which I use, but that's harder to describe.

¹not meant as a derogatory remark.

Re: 24/192 music downloads are silly

#302

Post by smosher_ »

dzhiurgis wrote: post #300

I am sorry, but the authors' examples and parallels doesn't make much sense to me. First of all, what does sample rate has even remotely to do with hearing range? If we are comparing this to visual information, perhaps it would be best to draw parallels with video. Namely, sample rate would be equal to frames per second and bit depth to colour depth. In both areas we are still seeing improvements from TV manufacturer…

> If we are comparing this to visual information, perhaps it would be best to draw parallels with video.

But it isn't. We perceive pitch more like we perceive color than how we perceive motion. "Motion" in audio is well below the frequency of pitch. Same goes for video really, but in video the framerate has nothing to do with the color, unlike how the sampling rate has to do with sound frequency in (cough most) digital formats. If color in video was sampled the way pitch is in audio, we would have framerates in the high terahertz range.

Re: 24/192 music downloads are silly

#303

Post by psychometry »

Stratoscope wrote: post #253
Lazlo_Nibble wrote: post #228

Earlier quoted context omitted.

Uh, no. Bit-perfect ripping is trivial and routine, and tools like the AccurateRip DB (which has checksums for around three million different titles you can use to verify the checksums on your own rips) and the CUEtools database (which has recovery records you can use to correct bit errors on your own rips) prove it. I routinely get bit-accurate single-pass high-speed rips--no "paranoid" settings or re-reads--of disc…

Oh sure, your rips may be perfect at the bit level, but how do you know that they're free of sub-bit quantization that isn't detectable by electronic circuits but can be heard by the human ear? This sub-bit jitter and interference can travel along with a digital file and sneak right past your ordinary bit-level error detection and correction, no matter how lossless you make it. That's because these errors aren't visi…

Flawless satire.

Re: 24/192 music downloads are silly

#304

Post by carlob »

cthalupa wrote: post #204
wodenokoto wrote: post #197

Earlier quoted context omitted.

Are Beats shitty or just expensive? How little would I have to pay to get same quality? I am finding it hard to believe that they are actually shitty, while I find it very easy to believe that they are way overpriced. I have never listened to Beats headphones but I imagine they have a lot of base-boost (based on absolutely nothing), but that is not the same as shitty.

So, we have to define, in your opinion, what would make a pair of headphones shitty. If you are going to reduce them to the basest level of what the purpose for a speaker or headphone is, to reproduce the input sound, then yes, they are shitty, because they are not good at that. From a purely objective standpoint, you are going to have to judge them based on that. Why would you want the speakers or headphones to make…

> You could buy a pair of Sony MDR-7506 that measure similarly (IIRC, a bit better, even) for $85.

Or Superlux HD668B which can be found for $30 last time I checked.

Re: 24/192 music downloads are silly

#305

Post by wander_homer »

dzhiurgis wrote: post #300

I am sorry, but the authors' examples and parallels doesn't make much sense to me. First of all, what does sample rate has even remotely to do with hearing range? If we are comparing this to visual information, perhaps it would be best to draw parallels with video. Namely, sample rate would be equal to frames per second and bit depth to colour depth. In both areas we are still seeing improvements from TV manufacturer…

"First of all, what does sample rate has even remotely to do with hearing range?"

The sample rate (among a few other things like the quality of the low-pass filter) determines what's the highest frequency you can perfectly read from a signal. Since most human beings can't hear frequencies above 20 kHz you simply need to choose a sample rate that can represent a 20 kHz signal perfectly and that's something like 44 or 48 kHz.

Re: 24/192 music downloads are silly

#306

Post by liotier »

errantspark wrote: post #18

I once spent ~2 hours explaining all of this (well maybe not all of it) to a friend of mine who was studying sound design at the time. He didn't believe me. I even transcoded some 24/192 FLAC Pink Floyd I had lying around and made him do a double blind test to show him that he'd prefer the slightly louder song every time, even if the louder song was 192kbps vs the FLAC. He did. He still doesn't believe me. He still t…

> He still thinks he can hear the difference between FLAC and MP3 to this day

I don't know if I would tell the difference in your test, but where I have noticed it the cause might be bad MP3 encoding - MP3 encoding quality varies widely... The difference between good and bad encoding may be far greater than between good MP3 and FLAC.

Re: 24/192 music downloads are silly

#307

Post by raverbashing »

tsotha wrote: post #280
masklinn wrote: post #30

Earlier quoted context omitted.

> Some people buy $500 wooden knobs to make their volume pots sound better. (or was that a hoax? i can't tell anymore) Some people buy small pyramids to elevate their cables off the floor, some people buy mats to put onto your CDs before putting the CD in a player ( http://dagogo.com/millenniums-m-cd-mat-carbon-cd-damper-revi... ), some people buy $1000+/meter digital interconnect cables ( http://www.theabsolutesound…

>Self-styled audiophiles are, by and large, idiots with way too much money plagued by magical thinking. I agree on the "plagued by magical thinking" part, but not all these people are idiots. Some of them are quite intelligent, in fact. I think they just want to be "in the know", and are able to suspend their normal skepticism in order to belong. One of the smartest and most productive programmers I ever met was take…

I have to laugh at this, really

But I suspect the metal ones are better. More magnetic shielding

So, IF your audio system uses a linear power supply (and it should) AND it is badly filtered (it should have good filtering) you can hear the 60Hz/50Hz from the power network (assuming it's not creeping in your system through other means as well - most likely they are)

Re: 24/192 music downloads are silly

#308

Post by lmm »

dietrichepp wrote: post #172
lmm wrote: post #132

You can't simultaneously say that you're dithering to represent low amplitudes while also saying you're keeping enough samples to capture all audible frequencies. Dithering doesn't create resolution out of nowhere, it sacrifices temporal resolution for amplitude resolution. It's also bad for compression (hence why modern video encodes are done at 10-bit even for output to 8-bit devices), and worse if you want to use…

> Dithering doesn't create resolution out of nowhere, it sacrifices temporal resolution for amplitude resolution. Could you elaborate on that? As I understand it, dithering trades distortion for uncorrelated noise, under the assumption that the distortion is more objectionable than the noise. Where did you come to the conclusion that temporal resolution is affected? The temporal resolution is instead related to the f…

The article talks about representing signals below the notional noise floor using dithering, which requires either temporal dithering or something morally equivalent to it - if your ear is detecting an average of dither + waveform, then it has to have several samples to average from.

Re: 24/192 music downloads are silly

#309

Post by Wicher »

gumby wrote: post #192
Wicher wrote: post #131

Earlier quoted context omitted.

> some people buy mats to put onto your CDs before putting the CD in a player An 80-minute, 700 MB CD-R fits 80 * 60 * 44100 * 2 * 2 / 2^20 ~= 807 MB of audio. Why is that? The 100MB difference is not just due to the audio TOC being of smaller size than the ISO9660 or UDF file system metadata. It's also because of differences in error correction. I don't have the spec on hand but I recall from when I was investigatin…

> Vibration is one of the factors that would make the same audio CD, read with the same CD player, produce different digital signals some of the time or even every time. Err, no. That makes sense when you have an analog version of the audio picked up by an analog transducer (i.e. a vinyl record) but makes no sense with an isochronous stream of quantized samples. I suppose a vibration could cause a small phase shift i…

From Wikipedia (Compact_disc lemma):

"[…] The change in height between pits and lands results in a difference in the way the light is reflected. By measuring the intensity change with a photodiode […]"

I'm no signals expert. Are you saying that there is no quantization in that intensity change measurement?

Regardless of quantization, maybe you're right on vibration not being a major source of errors (I know little about electronics and PLLs).

But then, what are the error sources that made the engineers put an extra 276 bytes of Reed-Solomon error correction per 2352-byte sector on a mode-1 data CD-ROM (vs none on an audio CD, which has just has the frame ECC and nothing extra). See https://en.wikipedia.org/wiki/CD-ROM#CD-ROM_format .

Re: 24/192 music downloads are silly

#310

Post by Wicher »

crazy1van wrote: post #268
Wicher wrote: post #131

Earlier quoted context omitted.

> some people buy mats to put onto your CDs before putting the CD in a player An 80-minute, 700 MB CD-R fits 80 * 60 * 44100 * 2 * 2 / 2^20 ~= 807 MB of audio. Why is that? The 100MB difference is not just due to the audio TOC being of smaller size than the ISO9660 or UDF file system metadata. It's also because of differences in error correction. I don't have the spec on hand but I recall from when I was investigatin…

> I read into this when I was wondering why my CD-DA extracted .wavs came out with a different checksum every time. You sure there isn't something in the wavs like a creation date field that would always cause the checksum to be different? That would make way more sense than "vibration"....

I did check by diffing the RIFF headers. Here's some info on the metadata: https://ccrma.stanford.edu/courses/422/projects/WaveFormat/ . There's little to no room for variance.
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