The reason for this, of course, is that there's no way to know whether the original waveforms were sampled near their max or near their zero crossings.
Intuitively, you would assume that this is the case, but for any frequency strictly less than half the sampling frequency, the sampling points would shift, giving you enough information to reconstruct the original waveform. If you sample at 22 kHz, and the signal is 20 kHz, you would see sample points near the zero crossing, as well as near the max.
you can't accurately reproduce an 88 nanosecond phase delay on a 20 kHz signal using 8-bit PCM at 44.1 kHz.
Correct. And I misspoke above when I said "quantized", I meant "sampled".
You can capture any delay with a 44.1 kHz sampled signal, in a bandwidth-limited source, even down to 88 ns, provided you have enough bits. .
Of course, in practice you don't have unlimited bits. The net effect of using fewer bits is that you add noise to the signal. With 16 bits, and no noise shaping, you could get 90 dB Signal/Noise ratio if everything else was perfect.
So, while you cannot achieve a perfect 88 ns delayed copy of the original 20 kHz signal, you can get that perfect 88 ns delayed signal summed with -90 dB noise. As long as you can't hear that noise, you can't hear the difference between the original signal and the reproduction.
Even then it's easier to control the artistic effect by recording it first at full range, and then filter it during post-processing until you get the effect you want.
So pure digital output from a sampler running at twice the frequency in question can produce a sine wave before filtering can it?
Normally, you would first increase the sampling frequency in the digital domain, and then convert to analog. The residual error can be pushed to the high frequency domain (> 100 kHz) where it can be easily removed with a simple analog filter.
Of course, a proper recording engineer isn't going to allow any clipping in the master recording. And once the master recording is finished, you can adjust gain and compression to produce any output format without further clipping.
but of course the filter has no way of knowing whether the original signal WAS a square wave , or sawtooth or triangle or anything else so to say it can reproduce it exactly is incorrect.
I said "provided they are below 22 kHz". A 22 kHz square wave has higher frequencies (all at odd multiples of 22 kHz, lowest at 66kHz and 110kHz), so it violates that condition. If you take a 22 kHz square wave, and you limit bandwidth to 0-22 kHz, you get a sine wave as the output.
None of this matters, as your ears cannot pick up the 66 kHz harmonics either, so you cannot tell the difference between a 22 kHz sine wave, square wave, or any other waveform with 22 kHz fundamental frequency.
At 96Khz 24bit recording resolution you are at the equivalent of current analogue tape.
Please provide a link to an analogue tape+recorder with S/R ratio of 144 dB.
However the other thing the human ear is sensitive to is harmonic frequencies, and if they are missing, it sounds weird.
There is no difference. If you can't hear a single 22 kHz note, you can't hear the 22 kHz harmonic of a 11 kHz fundamental tone either. Even worse, the presence of lower fundamentals have a blocking effect on our ability to hear higher frequencies.
Yes, but the argument that an analog reproduction of a 96khz source is more faithful than a 44khz CD is not incorrect.
The 44kHz CD can exactly reproduce all the waveforms in the 96kHz source, provided they are below 22 kHz. The analog vinyl can reproduce some waveforms over 22 kHz, but introduces distortion over the entire frequency spectrum.
Over the part that we can hear, the 44 kHz CD is more faithful to the original than vinyl. In either case, the differences are not due to the source material.
Also, none of the components in the sound system, such as filters, amplifiers, and microphones are designed to operate properly at ultrasonic frequencies.
If he couldn't make minor edits and teach from the last edition he would have to settle for the money he got directly from the school
I don't see why that would be undesired. The teacher is hired to teach, not to run his private business.
Also, the system should allow a student following an older book with minor differences can still pass all the tests. The tests should reflect the general knowledge you need to acquire the diploma/degree. When a hospital hires a surgeon, nobody cares about which version of the anatomy textbook he/she used.
since their bookstore sells you the books, and some of those were written by the professors.
When I went to university, about half my books were from the university publisher/bookstore and they were sold at cost (maybe $5-$10 depending on how big the book was). The rest were just generic textbooks we got at a regular book store. Both were reused year after year.
As a non-American, I find the whole concept of universities organizing sports teams bizarre. I went to university to get an education in my field, not to get involved in basketball or some other sport I don't care about. Other students, who were interested in those activities, could simply use their own money and get membership of an appropriate club and play in their free time.
Further studies delved into why women negotiated less aggressively and decided it's probably due to the cultural expectations of "niceness" and non-confrontationalism that women are raised with... and maybe even due to some inherent genetic bias in those directions.
When you're working with top actors, and they are not performing according to your vision, you need to be able to be confrontational. It's an important ability to have as a director. If you can't even bring yourself to demand a higher salary in a private office one-to-one conversation, how are you going to tell Bruce Willis or Julia Roberts, that they're doing it wrong again after 5 takes ?
book publishers realized that they have a captive audience of consumers that *have* to buy books every year (thanks to (often) unnecessary to book editions
It would be simple enough for the school to keep using the old edition.
Slashdot Mirror
The reason for this, of course, is that there's no way to know whether the original waveforms were sampled near their max or near their zero crossings.
Intuitively, you would assume that this is the case, but for any frequency strictly less than half the sampling frequency, the sampling points would shift, giving you enough information to reconstruct the original waveform. If you sample at 22 kHz, and the signal is 20 kHz, you would see sample points near the zero crossing, as well as near the max.
you can't accurately reproduce an 88 nanosecond phase delay on a 20 kHz signal using 8-bit PCM at 44.1 kHz.
Correct. And I misspoke above when I said "quantized", I meant "sampled".
You can capture any delay with a 44.1 kHz sampled signal, in a bandwidth-limited source, even down to 88 ns, provided you have enough bits. .
Of course, in practice you don't have unlimited bits. The net effect of using fewer bits is that you add noise to the signal. With 16 bits, and no noise shaping, you could get 90 dB Signal/Noise ratio if everything else was perfect.
So, while you cannot achieve a perfect 88 ns delayed copy of the original 20 kHz signal, you can get that perfect 88 ns delayed signal summed with -90 dB noise. As long as you can't hear that noise, you can't hear the difference between the original signal and the reproduction.
Wrong, harmonics do not exist in analogue world.
In the analogue world, square waves, sawtooth, or triangle waves don't exist either, so I guess we're even.
Even then it's easier to control the artistic effect by recording it first at full range, and then filter it during post-processing until you get the effect you want.
You totally misunderstand how the DAC recreates the original signal. Watch this educational video linked above: https://xiph.org/video/vid2.sh...
First off, that really only gives you 2 samples per WAVEFORM at 20 kHz.
Watch the video. It demonstrates how 2 samples is enough.
So pure digital output from a sampler running at twice the frequency in question can produce a sine wave before filtering can it?
Normally, you would first increase the sampling frequency in the digital domain, and then convert to analog. The residual error can be pushed to the high frequency domain (> 100 kHz) where it can be easily removed with a simple analog filter.
Of course, a proper recording engineer isn't going to allow any clipping in the master recording. And once the master recording is finished, you can adjust gain and compression to produce any output format without further clipping.
Note: a properly mastered CD should sound great at 16-bit, giving around 60dB dynamic range.
16 bit translates to 96dB, and noise shaping adds another 30dB.
You can try out the effects of noise shaping here with 8 bit samples: https://www.audiocheck.net/aud...
Probably the demand is only from a small group, not worth the effort.
That's just marketing. Higher numbers sell better. And now you get to buy the White Album yet again.
Sometimes the digital master for the vinyl version leaks out, and is highly prized by fans
So why don't they just sell both ?
Luckily, you aren't actually required to pay any attention whatsoever to the university sports, even if you go there
Unluckily, you are actually required to pay.
but of course the filter has no way of knowing whether the original signal WAS a square wave , or sawtooth or triangle or anything else so to say it can reproduce it exactly is incorrect.
I said "provided they are below 22 kHz". A 22 kHz square wave has higher frequencies (all at odd multiples of 22 kHz, lowest at 66kHz and 110kHz), so it violates that condition. If you take a 22 kHz square wave, and you limit bandwidth to 0-22 kHz, you get a sine wave as the output.
None of this matters, as your ears cannot pick up the 66 kHz harmonics either, so you cannot tell the difference between a 22 kHz sine wave, square wave, or any other waveform with 22 kHz fundamental frequency.
And the minimum phase difference in a CD corresponds to roughly a quarter inch difference in the free air path of the sound (napkin math) .
There's no loss of phase information in a quantized bandwidth-limited signal.
See this video https://xiph.org/video/vid2.sh... at 21:00
I mean S/N ratio, of course.
At 96Khz 24bit recording resolution you are at the equivalent of current analogue tape.
Please provide a link to an analogue tape+recorder with S/R ratio of 144 dB.
However the other thing the human ear is sensitive to is harmonic frequencies, and if they are missing, it sounds weird.
There is no difference. If you can't hear a single 22 kHz note, you can't hear the 22 kHz harmonic of a 11 kHz fundamental tone either. Even worse, the presence of lower fundamentals have a blocking effect on our ability to hear higher frequencies.
Yes, but the argument that an analog reproduction of a 96khz source is more faithful than a 44khz CD is not incorrect.
The 44kHz CD can exactly reproduce all the waveforms in the 96kHz source, provided they are below 22 kHz. The analog vinyl can reproduce some waveforms over 22 kHz, but introduces distortion over the entire frequency spectrum.
Over the part that we can hear, the 44 kHz CD is more faithful to the original than vinyl. In either case, the differences are not due to the source material.
Also, none of the components in the sound system, such as filters, amplifiers, and microphones are designed to operate properly at ultrasonic frequencies.
Pol Pot already knew that people are easier to rule if they are dumb as a doorknob
On the other hand, ruling over a bunch of doorknobs is not a recipe for long term prosperity.
A regular 44khz audio CD can't capture the full resolution of a digital master done at e.g 96khz
Mastering at higher resolution is useful for mixing and filtering, but a 44 kHz final output is enough to capture the full range of your ears.
If he couldn't make minor edits and teach from the last edition he would have to settle for the money he got directly from the school
I don't see why that would be undesired. The teacher is hired to teach, not to run his private business.
Also, the system should allow a student following an older book with minor differences can still pass all the tests. The tests should reflect the general knowledge you need to acquire the diploma/degree. When a hospital hires a surgeon, nobody cares about which version of the anatomy textbook he/she used.
since their bookstore sells you the books, and some of those were written by the professors.
When I went to university, about half my books were from the university publisher/bookstore and they were sold at cost (maybe $5-$10 depending on how big the book was). The rest were just generic textbooks we got at a regular book store. Both were reused year after year.
In other words vinyl's sound quality or lack thereof has mostly to do with the quality of the original recording
No, if everything comes from the same digital master, then vinyl's difference in sound quality comes from imperfections in the medium itself.
As a non-American, I find the whole concept of universities organizing sports teams bizarre. I went to university to get an education in my field, not to get involved in basketball or some other sport I don't care about. Other students, who were interested in those activities, could simply use their own money and get membership of an appropriate club and play in their free time.
Further studies delved into why women negotiated less aggressively and decided it's probably due to the cultural expectations of "niceness" and non-confrontationalism that women are raised with... and maybe even due to some inherent genetic bias in those directions.
When you're working with top actors, and they are not performing according to your vision, you need to be able to be confrontational. It's an important ability to have as a director. If you can't even bring yourself to demand a higher salary in a private office one-to-one conversation, how are you going to tell Bruce Willis or Julia Roberts, that they're doing it wrong again after 5 takes ?
book publishers realized that they have a captive audience of consumers that *have* to buy books every year (thanks to (often) unnecessary to book editions
It would be simple enough for the school to keep using the old edition.