Digital Enigma
100+ Head-Fier
Hey I’m just happy the thread is back on track
Adding to that question... and what kind of artifacts? It certainly can't fix compression artifacting or clipping.Can you provide an example of such artifact, before and after it is fixed?
As @danadam requested, please provide some examples of poor recordings where the audible artefacts are solved by an apodizing filter, and along the same lines:Apodizing filters can solve the artifacts caused by poor recordings.
What apodizing filters that are not a pathologically bad/broken design (Eg. That deliberately reduce fidelity within the adult audible freq range) will make “the hearing sense feel that the sound is far away” and “slightly dark”?The hearing sense will feel that the sound is far away, and some Apodizing filters will feel that the high frequency is slightly dark;
Could you please go into a bit more detail on what you mean by "an illegal signal" and "other illegal content". Thanks.
From what I understand, the Nyquist-Shannon sampling theorem simply states that the sample rate must be at least twice the bandwidth of the desired signal to avoid aliasing. So the 22.05kHz bandwidth limit is merely a function of having the sample rate used for 'CD quality' digital audio set at 44.1kHz. Now if we were talking about 'Hi-Res' digital audio with a 192kHz sample rate, then its Nyquist-defined bandwidth would be from 0Hz-96kHz.
A case can be made for an apodizing filter where the filter cuts off at 20kHz and opening up the possibility of reducing any aliased frequencies that folded back due to the ADC's filters not being good enough. So, objectively it could be argued that an apodizing filter can 'correct' for some of the ADC errors. The flip side to this is, given it is above the audible range, will it matter subjectively? If the roll-off starts any earlier than 20kHz, then it also opens up the possibility of reducing the highs.Can you provide an example of such artifact, before and after it is fixed?
it depends on how the filter is designed. An apodizing filter that is not abrupt (i.e., no sharp edge), but at the same time has high attenuation, can 'round' the edges where clipping occurs without much appearance of ringing. This would be easy to show and is aesthetically more pleasing to look at. When it comes to audibility, the fact still remains, this is still past the audible frequency range, so will it matter?Adding to that question... and what kind of artifacts? It certainly can't fix compression artifacting or clipping.
flip side to this is, given it is above the audible range, will it matter subjectively? If the roll-off starts any earlier than 20kHz, then it also opens up the possibility of reducing the highs.
In theory, does it correct artifacts? yes, it can correct some artifacts. Have I heard it correct artifacts? I can't hear past 16kHz.OK. It seems we are talking entirely in theory here. You haven't actually heard it correct artifacts.
What question was this whose answer is oversampling?And the answer to the second sentence is oversampling.
- Improve room acousticsI'm interested in information that can be used to make music sound better in the home.
Expensive DACs and snake oil cables have a shimmering mysticism to them for many that can feel "sexier" than installing acoustic panels on your walls and moving your speakers inch by inch to perfect the soundstage. Also, there is little doubt for these methods of working, so where is the debate?That seems like a good list to me! Oddly those subjects are rarely discussed at Head-Fi.
Yeah, that is a good add. Thanks!I’d add judicious equalization and signal processing to your list.
I was just helping keep the 'eye on the ball' so to speak. It is easy to loose focus when there are varying opinions and many of them can be correct too. Theory helps understand what is happening to the signals, how we perceive it is another story.I'm interested in information that can be used to make music sound better in the home. I understand that other people have fun with"what ifs" and discussions about theoretical or inaudible sound. It's just tough to discern the difference between stuff that matters and stuff that doesn't sometimes.
It is also an incorrect example because if you transform a dirac impulse to the frequency domain you get all the phases lined up while if you transform noise to the frequency domain the phase is going to be random. Any function that describes a phyisical quantity changing over time can be transformed back and forth between the time and frequency domain without any ambiguity.A frequency domain analysis will not provide the answer because there are infinite ways where a signal can be different in time domain but be exactly the same in frequency domain. An extreme example is an impulse, an impulse is when all the frequencies arrive at the same instant in time, but you get white noise when all those frequencies are spread apart.
Digital filters do not affect frequency response alone, they do affect how the different frequencies pass through them and the delay each frequency goes through.
On the contrary, that is exactly my point, but most of the analysis and measurements are done to highlight the frequency response. In theory yes you can go back and forth an infinite number of times, but for measurements, a lot of information is lost as FFTs are done with fixed window sizes and applying averaging and choice of the windowing functions and duration of the window affects how the frequency response looks and the phase response becomes useless at this point as it is time averaged and there is no way to just go back from there.if you transform a dirac impulse to the frequency domain you get all the phases lined up while if you transform noise to the frequency domain the phase is going to be random. Any function that describes a phyisical quantity changing over time can be transformed back and forth between the time and frequency domain without any ambiguity.