1. Download the equalizer presets using the following command
2. Install equalizer presets in Banshee 1.2 (Please note, this will write over existing presets)
gunzip -c equalizers.xml.gz > ~/.config/banshee-1/equalizers.xml
3. Start Banshee, Goto View -> Equalizer and choose what preset you want to use.
or use the following single command
Source from here