TXBDan

Righto, sorry guys! This is of course assuming that all audio signals are perfectly sinosudial. Which they are not.The other issue I see with the whole argument is that rate at which you can reproduce audio. What about asymetrical amplitudes. They do occur and would throw a nyquist 2 sample pardigm right out the door. Thats exactly what i was saying and was wrong about on the last page. The fact i missed and you're missing is that ANY wonky ass goofy shaped jaggedy asymetrical waveform can be created with a summation of sine waves of various frequencies. The highest frequency sine wave in that puzzle would be the one Nyquist is talking about and operating on. so double THAT frequency is the correct sampling rate

Ya know.. you're right. I'm an engineer and also have a DSP textbook up in the attic somewhere. That was a hard freaking class. When i pictured say for example a lumpy sine wave, i was thinking that one sample per half period wouldn't capture the lumps. But of course those lumps are coming from higher frequency sine wave components and so the Nyquist freq would be respective to those higher freq sine waves, not the big lumpy sine wave i was picturing. I forgot that all signals can be constructed by the addition of multiple sine waves of various frequencies. So with this in mind, you just need that highest freq component, and sampling it at double the freq is all the accuracy you need.

There is some seriously bad info in this thread. First, Nyquist's theorem (sample rate should be twice the signal's frequency) does NOT dictate that required or the best sample rate it dictates the MINIMUM sample rate. Its a rule of thumb not a hard and fast rule. a sample rate of 2*freq simple gives you one high point (+1) and one low point (-1) per sine wave period. It gives nothing in between. Secondly, yes as you double the sampling rate (say from 48k to 96k) you are able to capture twice as high frequencies (by Nyquist's theorem), but you also get double the capture resolution throughout the entire frequency range. So even at 500hz, 96k is twice as accurate than 48k. Its capturing twice as many samples per period of signal.