Talk:Digital

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Humans can only hear frequency's of upto 20kHz. There is more than 150 years of solid experimental proof for this.

It is therefore nonsence to use sampling frequency's much higher than twice that hearing threshold.

--Sin x 20:08, 14 August 2006 (BST)

Bollocks to that: http://www.tweakheadz.com/16_vs_24_bit_audio.htm and i quote: "Lets talk about sample rate and the Nyquist Theory. This theory is that the actual upper threshold of a piece of digital audio will top out at half the sample rate. So if you are recording at 44.1, the highest frequencies generated will be around 22kHz. That is 2khz higher than the typical human with excellent hearing can hear. Now we get into the real voodoo. Audiophiles have claimed since the beginning of digital audio that vinyl records on an analog system sound better than digital audio. Indeed, you can find evidence that analog recording and playback equipment can be measured up to 50khz, over twice our threshold of hearing. Here's the great mystery. The theory is that audio energy, even though we don't hear it, exists as has an effect on the lower frequencies we do hear. Back to the Nyquist theory, a 96khz sample rate will translate into potential audio output at 48khz, not too far from the finest analog sound reproduction. This leads one to surmise that the same principle is at work. The audio is improved in a threshold we cannot perceive and it makes what we can hear "better". Like I said, it's voodoo." - Ptah

Science is not voodoo, people understand it. That's why we can comunicate like this. Before you say it's bollocks read and understand this paper by Dan Lavry: http://lavryengineering.com/forum_images/Sampling_Theory.pdf Summary: It takes time to perform an accurate measurement. If the measurement time becomes short you loose accuracy. The optimal samplerate lies between 60kHz and 70kHz.

It's all nice that analoge can go to 100kHz, but people simply don't react to those frequency's so why try to capture them? Ofcause some instruments produce higher than 20kHz frequency's and these intermodulate also to produce frequency's in the audioband. But it's not the higher frequency's we hear but their intermodulation products, these can be captured and reproduced accurately with a 20Hz to 20kHz recording/playback chain. Electronic circuits alway's produce distortion, the distortion get more as frequency's go up. So if you do capture unhearable high frequency's, they will produce intermodulation distortion in the audioband. It gets worse when you want to prosess the sound. So in order to prevent these intermodulation distortion, make sure they are not present in the recording.

There's no repeatable scientific evidence that people react to frequency's above 20kHz. Therefore it's useless to use sampling frequency's higher than a bit more than twice the upper hearing frequency limmit.

Please keep sampling rates and bitdepths in the discussion section, and leave only general info in the article.

--Sin x 15:14, 16 August 2006 (BST)