What ? Eh ? Run that by me again ?

I remember reading a lot of articles when CD was first introduced concerning the type of anti aliasing filters used for digital recording. This is critical to prevent signals above 1/2 the sample rate from showing up in the recorded data. Early digital used analog filters for anti aliasing, which had issues with phase shifts in the audio bandwidth. Going to higher data rates (88 or 96) moves aliasing a full octave higher in the audio spectrum. There are microphones which can record higher than 20kHz, so this just gives added "headroom".

After a few years, manufacturers introduced 4x oversampling and introduced digital filters. But between 44.1 and 48K there is minimal difference (2kHz of audio bandwidth). The 44.1K spec came about as a compromise between Sony and Phillips. It comes from the B/W NTSC and PAL video recorder specs. These video recorders were being used for recording PCM data. Other systems such as the Soundstream system which was one of the early professional recorders used 50kHz as the sample rate.

48kHz comes from the European video signal. US TV people wanted to use 60kHz, but it was deemed "wasteful", so a lower data rate was used. There's an extensive examination of this here: The 48kHz Question

In terms of quality, I doubt anyone really can hear the difference between 44.1 and 48K. We're talking 1/10 of an octave in usable frequency (2kHz difference at 20kHz).
 
TalismanRich said:
I remember reading a lot of articles when CD was first introduced concerning the type of anti aliasing filters used for digital recording. This is critical to prevent signals above 1/2 the sample rate from showing up in the recorded data. Early digital used analog filters for anti aliasing, which had issues with phase shifts in the audio bandwidth. Going to higher data rates (88 or 96) moves aliasing a full octave higher in the audio spectrum. There are microphones which can record higher than 20kHz, so this just gives added "headroom".

After a few years, manufacturers introduced 4x oversampling and introduced digital filters. But between 44.1 and 48K there is minimal difference (2kHz of audio bandwidth). The 44.1K spec came about as a compromise between Sony and Phillips. It comes from the B/W NTSC and PAL video recorder specs. These video recorders were being used for recording PCM data. Other systems such as the Soundstream system which was one of the early professional recorders used 50kHz as the sample rate.

48kHz comes from the European video signal. US TV people wanted to use 60kHz, but it was deemed "wasteful", so a lower data rate was used. There's an extensive examination of this here: The 48kHz Question

In terms of quality, I doubt anyone really can hear the difference between 44.1 and 48K. We're talking 1/10 of an octave in usable frequency (2kHz difference at 20kHz).
Click to expand...
thank you Rich. This is all what I have come to understand.

Dave.
 
You must log in or register to reply here.
Back
Top