I'm using FreeBSD 10.2 with Xfce4, but I can't turn up the volume because there appears to be no volume control. I can hear sound faintly while watching youtube videos, but I can't turn up the system volume any further and the volume in the youtube controls is already turn up all the way. The volume control for the host OS on my computer are turned up almost all the way too. What should I do because I can't find a solution and mostly get suggestion for Microsoft Windows.