Encode MP3 correctly - you should pay attention to these settings
If audio files are saved in MP3 format, signals that are inaudible to humans are cut off. We will tell you how to correctly encode MP3s in order to achieve the best quality.
What is MP3?
In order to optimally encode an MP3, it is important to have an idea of how MP3 works:
- MP3 is an audio codec for the MPEG I standard developed by the Fraunhofer Institute, especially Karlheinz Brandenburg.
- MP3 is a compression method that the psychoacoustic takes advantage of: the audio signal is divided into narrow frequency bands. Spectral components that people partially or completely ignore are stored with less accuracy.
- The lower the specified bit rate, the less precise the mapping and the more likely it is that frequencies above the masking threshold will also be stored imprecisely.
Encode MP3 optimally
Depending on whether you want to rip music from CD, voice recordings, or encode recordings from analog media such as records, different settings are suitable in some cases. Others always make sense. You can make all settings, for example, in XMedia Recode, which CHIP Online offers free of charge.
- In general, it makes sense to keep the sampling rate of the file to be encoded. For audio CDs, this is 44100Hz. For recordings of records or cassettes, 32000Hz is enough, speech remains clearly understandable even at 22050Hz.
- For pure voice recordings, mono is sufficient; for music, joint stereo is usually more efficient than simple stereo, since some bits can be saved without loss through mid-side coding.
- As a bit rate mode, VBR-ABR (Variable Bit Rate - Average Bit Rate) is always the means of choice: Here, in the passages in which frequency ranges are clearly masked or where there is absolute silence, an enormous amount of data is saved that makes sense elsewhere be used. Depending on the type of signal, an MP3 with a VBA ABR bitrate of 128kpbs on average can be significantly more accurate than a file with a constant bitrate (kBR) of 160kbps. In any case, with the same file size, it is always at least as good as a kBR file with the same bit rate.
- To exploit this potential, you should set the VBR quality to the maximum, the minimum bit rate to 32kbps and the maximum to 224.
- Depending on how nuanced your music is, an average bit rate of 128 to 192kbps is usually ideal. Of course, mono files only need half the bit rate. For speech, 32 to 48 are enough to understand, up to 64kbps for somewhat clearer sound. Here you can also use a high pass from approx. 90 Hz.
- Of course, you get the best quality if you set the quality to "high". This means that the coding takes a little more time, but with today's processor performance, this hardly matters.
- It is completely pointless to subsequently encode an MP3 with better quality or to save a mono file in stereo.
This practical tip explains how you can optimally manage your well-coded music collection.