why sample bitrate of 44100KHZ is so common

[boomstick666]

Some formats use higher frequencies. I think DVD audio and SACD are 192k; not sure.

SACD's sampling rate is 2.8224 MHz (DVD-Audio is 192KHz 24bit max), 1-bit sigma-delta modulation process known as Direct Stream Digital (DSD).
SACD (Super Audio CD) is by far the best digital audio format available.

 

[EricB]

nero has higher encoding options. I rip at 445 kbps mp4 files with nero