5 Apr
2009
5 Apr
'09
4:04 a.m.
Hi,
Julien Claassen wrote:
I guess filter below 20Hz and above 20kHz is fine,
you can't hear it if your
older than a young child and belong to the human species. When to filter: as
early as possible or as late as possible? I'd guess: better later.
a lowpass filter above 20kHz is already included in any AD converter to
avoid aliasing. If your material is recorded using analog sources then
this lowpass is not needed explicitly during mastering (I don't have any
experience with digitally created music, but also the DA converters have
anti-aliasing filters). If you recorded sounds with microphones at weak
levels, e.g. classical acoustic instruments, your signal may contain low
frequency noise at a bad SNR caused by environmental noise. If you used
omnidirectional microphones or if you recorded in an urban environment I
would apply a high pass filter near 40 Hz at a stage as early as
possible. With good near-field monitors you will not hear this noise,
because they usually have a very steep high pass in that frequency
range, but typical consumer systems don't have a high pass (or even come
with extreme bass boosting) which may make this noise very audible.
Giso