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Topic: MP3 frequencies above cutoff (Read 1118 times) previous topic - next topic

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MP3 frequencies above cutoff
Is there any point to frequencies above the cutoff point on an MP3 file? Does it mean it's a transcode or it's a better quality file than one which is just cutoff completely with no frequencies above the cutoff line. Which files should I keep when two different files of the same song has this issue. Which one's better quality?

Thank you for any help.

Re: MP3 frequencies above cutoff
Reply #1
Why don't you start by reading this?

It's a good starting point; sure to shed some light on (part of) what you asked.

BTW, the tell-tale sign of transcoding usually translates into audible artifacts.
No spectral analysis is going to tell you that. (assuming it's that what you've used to see all this difference)
Listen to the music, not the media.

Re: MP3 frequencies above cutoff
Reply #2
And maybe complement that with this.
Listen to the music, not the media.

  • mjb2006
  • [*][*][*][*][*]
Re: MP3 frequencies above cutoff
Reply #3
Different encoders make different decisions about what frequencies to keep. They are trying to strike a balance between quality and space (bitrate). Keeping frequencies above 16 kHz invokes a much more painful tradeoff of quality and space, and that region rarely contains audible content, so you often see a cutoff around there.

There is no way to know which file has better quality without listening and comparing (after matching the volume levels, e.g. with ReplayGain). Even then, you may well just be picking the one you like better, since you don't have an original lossless copy to compare it to, nor are you certain that the two MP3s even came from the same source. You also can never be 100% sure something was transcoded; there are some things you can see in a spectrogram sometimes, but it's not as simple and absolute as seeing a cutoff.

Keep what you like the sound of, or make your own rips from original sources, and you won't have to worry.
  • Last Edit: 19 August, 2016, 07:07:07 PM by mjb2006