431–440 of 443 posts
Anyone here who has not already seen Xiph's Digital Show and Tell ( http://xiph.org/video/vid2.shtml ) should do themselves a favor and sit down for a watch. It makes sense of a lot of mysteries and misconceptions around digital audio.
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Sure 22,050hz and 11,025hz get smoothed out into perfect sine waves and the human ear can't hear 22Khz anyway. But the Nyquest frequency isn't some magical threshold that you cross and suddenly everything is perfectly preserved. It's a folding frequency that determines where aliasing is going to occur, or rather where it's not going to occur. A 44Khz sampling rate is based roughly on western tuning (440Hz A) and make…
Which gets back to your original point about both sample rate and bit depth contributing to the dynamic range. I'm very curious: can you give me some search keywords that would get me to the math behind that? Also, I've never heard the claim that the 44.1kHz rate biases toward 440Hz tuning, is there somewhere I can read more about that?
44.1kHz/100 = 441hz. But that's nonsense in the same way that saying that a signal at the Nyqvist frequency can be accurately encoded. @diroussle pointed out that you lose phase but there's another consideration, sync. If your signal at Nyquist is not in sync with the sampling frequency, then it's going to be represented as a signal offset, an out of phase line.
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Sure 22,050hz and 11,025hz get smoothed out into perfect sine waves and the human ear can't hear 22Khz anyway. But the Nyquest frequency isn't some magical threshold that you cross and suddenly everything is perfectly preserved. It's a folding frequency that determines where aliasing is going to occur, or rather where it's not going to occur. A 44Khz sampling rate is based roughly on western tuning (440Hz A) and make…
>It's ridiculous in a world of 5K retina screens that people can't see the value in higher resolution audio. Not if they can't hear the value in higher resolution audio. For many people the only difference in HD audio over 16-bit 44.1 Khz is that the files are bigger. If someone can't hear the difference, it's no surprise that they don't care to move to a new format. The screen analogy isn't perfect as most people ca…
Don't argue from a position of ignorance. Make friends with a recording engineer and have them play you a 32bit mix followed by a 16 bit mixdown.
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> 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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Did you read the article? "The ultrasonics are a liability during playback.... Neither audio transducers nor power amplifiers are free of distortion, and distortion tends to increase rapidly at the lowest and highest frequencies. ...any nonlinearity will shift some of the ultrasonic content down into the audible range as an uncontrolled spray of intermodulation distortion products covering the entire audible spectrum…
That's what audio mastering is for. A good mastering engineer tests their masters on iPhone headphones as well as studio monitors. > I would not expect a willingness to exploit consumers' magical thinking to be a good signal for quality engineering. Companies do this all the time, not just in audio, and they have for years. I don't know why most consumers would need a phone with a camera more than 8 MP, when most use…
Yes, I agree they do. A lot. Do you think that should make you want to buy their products more? That was what the parent was claiming.
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And there are jobs created for engineers who design that equipment - simultaneously recycling more money in the economy and contributing to the statistics of STEM job prospects! Everybody wins!
Broken window fallacy.
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The experiment would also be extremely difficult to design. I disagree. I think all the factors you are concerned about can be eliminated with a large enough sample size, like in the thousands (or maybe 10s of thousands). You allow each person to select the genre of music they like, and you play a few clips from a few songs of each bitrate. Then they guess which is 24-bit and which is 16-bit. I'm not paying to set it…
Pretend your headphones only moved with 8-bit resolution. There is no possible way the experiment could derive a useful conclusion, but you might trick yourself into thinking it did. Especially if your sample size was 10,000 people. More realistically, the participant might choose music for which no 24-bit recording exists. It's very important to control for every variable. It's actually not possible to gather info a…
It's not, actually. Say you have 10,000 listeners and you randomly assign each one to 16-bit vs 24-bit listening. You have enough listeners that any differences between the groups are due to chance and will very close to even out. Now, if you find people are unable to distinguish between 16-bit and 24-bit you might want to try the test again with more control over the environment, but if you find a substantial difference in a large blind randomized test that's a real finding.
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Which gets back to your original point about both sample rate and bit depth contributing to the dynamic range. I'm very curious: can you give me some search keywords that would get me to the math behind that? Also, I've never heard the claim that the 44.1kHz rate biases toward 440Hz tuning, is there somewhere I can read more about that?
pulse code modulation, pulse density modulation... 44.1kHz/100 = 441hz. But that's nonsense in the same way that saying that a signal at the Nyqvist frequency can be accurately encoded. @diroussle pointed out that you lose phase but there's another consideration, sync. If your signal at Nyquist is not in sync with the sampling frequency, then it's going to be represented as a signal offset, an out of phase line.
In any case, thanks for your patience, I'm glad to have cause to reconsider my position on this topic.
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The thread at https://news.ycombinator.com/item?id=8210878 (assuming StavrosK was not lying like one of the comments suggested), shows an interesting discrepancy in the vision of different people.
Monty actually mentions this in the footnotes of the article: > The original version of this article stated that IR LEDs operate from 300-325THz (about 920-980nm), wavelengths that are invisible. Quite a few readers wrote to say that they could in fact just barely see the LEDs in some (or all) of their remotes. Several were kind enough to let me know which remotes these were, and I was able to test several on a spect…
So there are even two moving targets - the LEDs' lower wavelength and different humans' higher wavelength.