For our radio station we broadcast on 64kbps. When testing airtime I noticed the sound's quality was poor. Couldn't blame liquidsoap for reencoding because I used it before on the same songs. I then saw in ls_script that when defining output.icecast you only define the bitrate. The default for samplerate is 44 100. But at low bitrates the quality of the sound way become very poor. I hardcoded the script and now it's ok. For 64kbps we use 22 050 for samplerate.