When you export you should see “Format Options” below where you enter the file name. Choose Constant Bitrate Mode and 192 kbps (or higher) for Quality.
You can use file analyzer to get source audio's detailed information such as track name, genre, bitrate and sampling rate. 2. Set target audio format, bitrate ...
On this page you can convert audio files between various formats.The most popular: AMR to MP3, OGG to MP3, RAM to MP3, WAV to MP3, WMA to MP3, FLV to MP3, MOV ...
There are several online tools that can improve the quality of MP3 or M4A files. One popular tool is called Auphonic (Auphonic), which uses advanced algorithms.