The audio files are recorded off the midi files through Yamaha PSR-E323, recorded in 24-bit/48khz.
Later they are converted to different format (16-bit, mp3) from its original 24-bit/48khz, so audio quality are kept to its best for each audio format.
This is because there is a difference in audio quality if you originally record it in mp3 format, then convert to other formats. If you do this, even if you convert to wav format, the audio quality has already been lost, and the wav file you are now playing is similar to playing the mp3 file, just that the file size is larger.
Recommended format playback:
mp3: PC with any PC speakers
wav 16-bit: For high-fidelity loudspeaker system
wav 24-bit: For high-fidelity loudspeaker system that supports 24-bit
Audio Format:
.mp3 - 48kHz/192 kbps (Constant Bit-Rate)
.wav 16-bit - 44.1kHz/16-bit
.wav 24-bit - 48kHz/24-bit
