
Eric Johnson.....
http://korg.com/MediaPlayer.aspx?md=3947
i thought that the 44.1KHz thing was kinda like the common ground (number) for both PAL & NTSC. i've read an article somewhere explaining the number 44.1KHz & like why it wasn't rounded down to 44KHz or something..As we mentioned, the human hearing range tops out at about 20 kHz, and the Nyquist theorem shows that we need to sample at slightly faster than double that. This is how CDs ended up using 44.1 kHz as their sampling frequency. It is the lowest rate that assures accurate sampling through the entire hearing range.
After spending some time reading, multi subjects are crossed.Pi2plank wrote:yeah, the article was quite a good read.. but this had me wondering..
i thought that the 44.1KHz thing was kinda like the common ground (number) for both PAL & NTSC. i've read an article somewhere explaining the number 44.1KHz & like why it wasn't rounded down to 44KHz or something..As we mentioned, the human hearing range tops out at about 20 kHz, and the Nyquist theorem shows that we need to sample at slightly faster than double that. This is how CDs ended up using 44.1 kHz as their sampling frequency. It is the lowest rate that assures accurate sampling through the entire hearing range.
Bingo. It's all about the Nyquist theorem. Ideal audio equipment can in theory reproduce perfect audio from a CD up to 22,050 Hz. The key word is "ideal" -- as higher fidelity audio sampling technologies make their way into our living rooms (DVD-A, SACD) it is becoming easier for us to reproduce great audio with consumer products that mere mortals can afford.FRETPICK wrote:After spending some time reading, multi subjects are crossed.Pi2plank wrote:yeah, the article was quite a good read.. but this had me wondering..
i thought that the 44.1KHz thing was kinda like the common ground (number) for both PAL & NTSC. i've read an article somewhere explaining the number 44.1KHz & like why it wasn't rounded down to 44KHz or something..As we mentioned, the human hearing range tops out at about 20 kHz, and the Nyquist theorem shows that we need to sample at slightly faster than double that. This is how CDs ended up using 44.1 kHz as their sampling frequency. It is the lowest rate that assures accurate sampling through the entire hearing range.
http://en.wikipedia.org/wiki/Red_Book_% ... tandard%29
http://en.wikipedia.org/wiki/Nyquist_frequency
http://en.wikipedia.org/wiki/Nyquist_rate
http://en.wikipedia.org/wiki/Sampling_t ... _frequency The math behind.
http://en.wikipedia.org/wiki/Digital_audio AD-DA.
Found it.
http://en.wikipedia.org/wiki/Compact_disc
"A standard NTSC video signal has 245 usable lines per field, and 59.94 fields/s, which works out at 44,056 samples/s/stereo channel. Similarly, PAL has 294 lines and 50 fields, which gives 44,100 samples/s/stereo channel. This system could either store 14-bit samples with some error correction, or 16-bit samples with almost no error correction.
There was a long debate over whether to use 14-bit (Philips) or 16-bit (Sony) quantization, and 44,056 or 44,100 samples/s (Sony) or around 44,000 samples/s (Philips). When the Sony/Philips task force designed the Compact Disc, Philips had already developed a 14-bit D/A converter, but Sony insisted on 16-bit. In the end, 16 bits and 44.1 kilosamples per second prevailed. Philips found a way to produce 16-bit quality using their 14-bit DAC by using four times oversampling."