Hi! I haven't used the equalizer functionality of Vlc much, so hadn't noticed it wasn't working (at least for me). If I click on 'enable' it would appear to activate, yet there would be no alteration of tonal quality/ preamp gain etc. I rebuilt vlc a couple of times (backtracking git commits) until I located the point at where the problem began. It seems to have begun at the commit: libvlc: add equalizer API (2013-07-24). Building Vlc from the commit prior to that (avcodec: add assertion after vlc_va_Get() + cosmetics) and the equalizer worked as expected.
Back to the commit: ' libvlc: add equalizer API', experimenting a little I found that removing a line from /src/audio_output/filters.c > var_AddCallback (obj, "equalizer-bands", EqualizerCallback, NULL); [approx line 420] and the equalizer would work again.
(I'm using Ubuntu/linux by the way).
Regards.