Mp3, 128kBit/s: What the difference in Hertz?

With 128 kBit/s mp3 stereo, what’s the difference in using 44,100 Hertz versus 48,000 or 32,000 Hertz?


44,100 Hz will be more compatible than the other sampling frequencies.

I would consider using 32kHz and 48kHz only of the original content is using those sampling frequencies, and even then I’d consider resampling to 44.1kHz - when mp3 encoding audio from music DVDs, I re-sample to 44.1kHz because it’s more widely compatible with tools and players.

Theoretically the sampling frequency will also influence which frequencies that will be present in the mp3 encoded file, but at a fairly low 128 kbps there wouldn’t be much if any difference in practice, I think.

Unless there is a problem with particular sample rates (eg. the target player cannot handle 48kHz), I’d avoid resampling.

The most common would certainly be 44.1kHz CD-rip, so that is kind of a standard. Encoding lower sample rates may make things a little easier for the encoder - at lower bitrates, the sample rate is usually reduced. Resampling has its own losses, so you need a very good reason to do it.

At 128k, you would also generally use joint stereo, unless the material has abnormally high seperation.

Actually, at 128k, using ABR (average bit rate) or a “close to 128k” VBR would be better, but less compatible than 128k CBR - some players have problems with track times in non-CBR modes if nothing else.

I’m using High Criteria’s Total Recorder. It seems to have some way of utilizing VBR, but I’m not even sure if I can invoke it with mp3. I have always used CBR. I never even thought of using the VBR.