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Lee H said:What if you use a flux capacitor?
Ah, finally, an interesting subject. I like the fact that the DOC got it to run on garbage. Now that , my friend, is re-cycling.
Lee H said:What if you use a flux capacitor?
tremon said:Can you pass both waveforms through a 20kHz low-pass filter, and show those results as well?
MajorFubar said:No the waveforms are not dithered or filtered; naturally, dithering will smooth the signal a great deal in both instances, but the fact still remains that the 96kHz version gets closer in the first place. Dithering is clever and effective to a degree, but it can never really put back missing information. Real audio is far more complex than a basic sine wave, which I used for example and simplicity. I haven't 'joined the dots' as such (though I know what you mean): I created the sine waves in Sound Forge and zoomed-in to roughly a 1 millisecond sample of each. I did it just to show visually the raw difference between 44.1kHz and 96kHz, because pictures paint a thousand words.
krazy_olie said:THat's the point really, a 20khz LPF will effectively be an antialisaing filter but a lpf will be prefect unless you have a very high order filter. Remember the nyquist theorem works mathematically but when you bring in real engineering costs it doesn't work quite as well.
Ok, I understand. I guess it's not really SF's fault either to draw it like that, but still -- no audio equipment will ever be able to produce a waveform like that, you would need an industrial-strength signal generator.MajorFubar said:I haven't 'joined the dots' as such (though I know what you mean): I created the sine waves in Sound Forge and zoomed-in to roughly a 1 millisecond sample of each. I did it just to show visually the raw difference between 44.1kHz and 96kHz, because pictures paint a thousand words.
tremon said:com oan geiezze a brake its getting farcical and funny with all the tech heads.
krazy_olie said:THat's the point really, a 20khz LPF will effectively be an antialisaing filter but a lpf will be prefect unless you have a very high order filter. Remember the nyquist theorem works mathematically but when you bring in real engineering costs it doesn't work quite as well.
When applied to a signal before quantization, an LPF acts as an anti-aliasing filter. You are correct that you need a very steep filter to prevent frequencies above the Nyquist frequency from folding back and causing distortion, which is why a higher sampling rate is much better: they can work with a cheaper filter and still produce less aliasing in the audible range.
A low-pass filter applied to a discrete signal works as an integrator (smoothing filter): it smoothes out the waveform and removes the high-frequency components introduced by the discretization. You don't need a very steep filter for that, because most of the additional noise will occur at multiples of the sampling frequency instead of near the baseband signal.
Ok, I understand. I guess it's not really SF's fault either to draw it like that, but still -- no audio equipment will ever be able to produce a waveform like that, you would need an industrial-strength signal generator.MajorFubar said:I haven't 'joined the dots' as such (though I know what you mean): I created the sine waves in Sound Forge and zoomed-in to roughly a 1 millisecond sample of each. I did it just to show visually the raw difference between 44.1kHz and 96kHz, because pictures paint a thousand words.
Lee H said:What if you use a flux capacitor?
al7478 said:Lee H said:What if you use a flux capacitor?
Incest nearly ensues, and the clocktower is in grave danger, and nobody wants that.
steve_1979 said:I've just tried comparing 320kbps MP3's to lossless files using my new AVI system and I couldn't tell any difference between them.
steve_1979 said:For this test I used 4 albums that I consider to be of the very highest sound quality in terms of recording and mixing. They were ABBA, Alan Parsons, Michael Jackson, and Mozart (Amadeus soundtrack).
iemslie said:But who the hell wants to sit concentrating on every note? Surely the point of music is for either relaxing and enjoying, or jumping about and having a lark.
steve_1979 said:Andrew. Silenced.
steve_1979 said:At work we often listen to rubbish quality YouTube music through tinny PC speakers and I still get just as much enjoyment as I do from listening to my hifi at home
steve_1979 said:If your unable to enjoy music unless it's played through several thousand pounds worth of hifi equiptment then I feel very sorry for you.
Clare Newsome said:I wish people would respect the fact that while we all have different brains and ears, there is no right and wrong about hi-fi, just opinions.
Clare Newsome said:No problem. I just get incredibly frustrated/depressed by threads like this that
a) include vast amounts of techno-twaddle that bear little/no relation to the highly subjective, emotive experience that is music-listening and
b) incredibly arrogant assumptions that just because a poster has had one experience that everyone else *must* hear the same.
There are room for as many (if not more) opinions than there are choice of systems, formats and music
PS After this morning's digital delights, I am currently listening to heavyweight, 45rpm vinyl engineered by Steve Hoffman. Anyone whom doesn't think it sounds awesome is an idiot ;-)
MajorFubar said:Not really, though I do confess I made a typing error due to being distracted (by my kids), and for that I apologise: I meant samples per cycle not samples per second, but the basis of what I said still stands: 4 samples per cycle of a 10kHz sound is not very much.snivilisationism said:Possibly, what do you mean with 4 distinct samples per second? Unless for some reason you're dividing 44.1 Khz "sample rate", by 10 KHz "frequency"... That's a bit like dividing 8 by fish. Either way, I can't tell the difference.
The theorem is correct that you need to at least double the sampling frequency, because audio waves have a 'plus' and 'minus' value which one sample per cycle wouldn't capture. But just two samples per cycle most certainly don't give a 'perfect reconstruction'.snivilisationism said:And, the Nyquist-Shannon theorum states simply that you need twice the sampling rate than the highest frequency to get "perfect reconstruction of the original wave". I understood that above that, it makes no difference to the end result as the algorithm will yield the same (perfect result). ie the sound at a particular frequency will be exactly the same. If it isn't, then the theorum is wrong, and someone needs to go back to the drawing board.
The below screenshot shows two 1/1000th of a second snippets of a 10kHz sine wave. The top one is sampled at 44.1kHz and the bottom one at 96kHz. As you can see, the top wave is not very good at all while the bottom one more accurately represents a truer shape of the wave.