Hi friends, I installed Antergos (XFCE) on my desktop a week ago.
Volume control keys on my keyboard and my USB headset were not working.
I just installed Xbindkeys. Voila! Most keys are working fine now!
(Not sure if this step is necessary. But soon after installation, I ran this command to create sample configuration. => xbindkeys -d > ~/.xbindkeysrc)