Your remark about the equalizer playing a role here could indicate that your distortion is a result of too high volume levels. You could investigate the volume levels as set in, or influenced by: Windows (mixers), your soundcard drivers and settings, MusicBee's dsp and pre-amp settings, replaygain (adjusted too high?), etc. etc.
If you are in need of using the equaliser, try to make a habit of lowering the levels you experience as being too loud, instead of increasing the bands you experience as too soft.