mp3's : 44.1KHz or 48KHz ?

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • Vulcan
    Junior Member
    Junior Member
    • Dec 2002
    • 23

    #16
    the mp3 psychoacoustic model is based on the devision to critical frequency bands in out brain and on the masking effect . not on a simple low pass filter.

    moreover...test signals were played back for an audiance with systems limited to 20KHz and 40KHz, and people found the sound coming from the 40KHz system to be of better quality.

    Comment

    • benderman
      Digital Video Specialist
      Digital Video Specialist
      • Nov 2001
      • 770

      #17
      @Vulcan:

      20KHz and 40KHz
      There is a differnce between the samplingrate and the maximum frequency. With 20kHz samplingrate the max frequency will be 10kHz and with that much missing frequencies everybody will notice the low quality. But if you reduce the samplingrate from 48kHz to 44.1kHz it will only kill the frequencies higher than 22.05kHz.

      But after all there is no need to reduce the samplingrate before compression, because all lossy codecs reduce the higher frequencies automaticly if the bitrate is to low.
      don't trust in guides

      Comment

      • Vulcan
        Junior Member
        Junior Member
        • Dec 2002
        • 23

        #18
        benderman you're right...

        it is obvious (i think..) that when i talked about a 20KHz system the sample rate is at least 40KHz and 80KHz for a 40KHz system..

        your previous comment wansn't clear enough, but now you made your point -> at lower bit rates there is an initial frequency cut off (Low pass filtration)

        Comment

        • benderman
          Digital Video Specialist
          Digital Video Specialist
          • Nov 2001
          • 770

          #19
          maybe it's my bad english ...
          don't trust in guides

          Comment

          Working...