This procedure worked for me. You cannot make a custom equalizer setting, but you can customize the standard presets to your liking.
-on VLC 2.0.4 version press Ctrl+P to go on Preferences settings (Tools, Preferences)
-on the bottom left at "Show settings" choose "All"
-in left panel choose Audio > unfold (Audio > Filters) > press Filter and choose "Equalizer with 10 bands"
-in the left panel click on "Equalizer" (Filters, Equalizer)
-in the "Bands gain" label type the value for equalizer:
ex. -0.40, 0, 0.80, 2.70, 4.00, 4.20, 0.60, 2.10, 6.50, 6.50 > 10 bands
and "Global gain" > 10.00 or less
-in the bottom right click "Save".
Ken
Example: