Turntables worth it?

[DJeffries]

Originally Posted by richteer

Nyquist's Theorem is fine for simple sine waves; unfortunately, music is not made up of simple sine waves! The need to accurately reproduce the complex harmonics that make up a music signal is where proponents of Nyquist fall down..

Actually Nyquist works for any band limited signal such as music. Any band limited signal can be digitized and exacly recreated (given good enough A/D and D/A conversion) providing you adhere to the Nyguist-Shannon criteria which CD does. Also all signals no matter how complex they may appear on a scope (music signals included) can be represented by adding simple sine waves together. Hanser is 100% correct in his assessment of CD vs vinyl accuracy.

Music as well as anything else you hear is band limited as the cochlea (the anatomy in your ear that converts pressure waves to electrical signals) only responds to pressure waves from about 20Hz to 20KHz effectively filtering the signal. It then sends frequency and amplitute information to the brain in a discrete fashion, it is not a continuous device. Therefore you have the same range of filtering happening inside your ear that is applied in anti-alias and reconstruction filters for digital sound. So the harmonics above 20KHz and thier effects at lower frequencies never make it to the brain anyway.