Sound in Pidgin becomes messed using ALSA with equalizer enabled

[Hebgbs]

As it says on the tin. Mind, I had no problems before and this is only a recent issue, which doesn't rear its head in a live session of Manjaro MATE but on the installed system — no matter what, without fail — the audio for Pidgin (and I presume other GTK applications) becomes messed up.

Had anyone else encountered this? And if so, what's the fix? I've spent the better part of a day reinstalling my system multiple times with no good result.