|Advanced Audio Recording|
Comparison between 48kHz,96kHz,192kHz and 384kHz sample frequency
In recent years 96kHz sampling frequency was recommended for modern audio recording. This article shows some technical background, why this is the case. Please also read the article: Do we need 96kHz ?
The advantage of higher sampling frequencies
From the theory the current 48kHz frequency seems to be sufficient since it can represent up to 24kHz which is the half of the sample rate and defines the so called nyquist's frequency. Using an appropriate reconstruction filter, all frequencies below this border might be correctly restored. Practically this required an ideal anti aliasing filter which does not exist and cannot be constructed neither in analog nor in digital domains. This leads to the conclusion that some headroom is necessary to reduce the amount of frequencies beyond nyquist to avoid the negative effects of mirror frequencies. Please see this article of the comparison 48/96 for details.
In the digital domain, filters are often realized by FIR filters which vary in complexity and size and therefore demand more or less calculation power.
The subsequent image shows 4 different versions of audio filters (high cut) and their edge frequency:
|© 2004 J.S.|