Render to mp3 - change sample rate?

I have a wav file recorded at 48 kHz. I want to render to mp3 using the factory presets.

As far as I can tell the sample rate is set to Match Input Stream in all of the presets so I would expect the resulting file to be 48 kHz, same as the source file. But some of them (pictured in red) change the sample rate to 44.1 kHz. Is this a bug or am I missing a setting somewhere?


Are you sure ?
Check with MediaInfo app or read back file in WaveLab
WL keeps sample rate and changes only if you tell to…

regards S-EH

The final mp3 sample rate is decided by the encoder. Usually, this is the same as the input, but it could be reduced. Indeed, remember that the mp3 process is to remove the most minor hearable frequencies to reduce the size of the file. The encoder might decide to remove the frequencies above 20 kHz hence switching from 48k to 44k.


Thanks @PG1

This is interesting. Looks like there is no way to force a sample rate? Even if I select 48 kHz instead of Match Input Stream the resulting file is 44.1 kHz in this case.

Yes, I did check both MediaInfo and Wavelab.

If you increase the bit rate setting or vbr quality setting, this could accept 48k.

pick a factory setting, then"edit single format" of the mp3 you want to use, and adjust the sample rate to what you need and export with whatever kbps you need, would that not do it?

That’s what I thought. But it renders to 44.1 kHz even if sample rate was explicitly set to 48 kHz in edit settings dialog.

I will try higher bit rates as @PG1 suggested.

I can render to 48kHz but I need to be careful which preset and settings I choose. The 128 k cbr and 320 k cbr hq seem to work fine.

@misohoza FYI what you are seeing is linked to the hq (high quality) switch.

  • with hq on, the only bit rate which will allow you to retain a 48kHz sample rate is 320kbps.
  • with hq off, you can choose lower bit rates while still retaining the 48kHz sample rate.
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