I've found the issue,
if we go to System Tools -> Settings Editor -> xfce4-mixer
you need to set the property "active-card" to the value of the card you want to change volume for. This is independent of which card is active for alsa by default.

However the mute is still broken. When you press mute, it mutes both Master & Speaker, when it unmutes it only unmutes property "active-track" which is typically Master OR Speaker.



On Saturday, September 3, 2016 at 1:07:01 PM UTC-4, sebast...@gmail.com wrote:
> In 3.2-rc3 the volume buttons still don't work for me either. I had to set the master card to #1 rather than #0 but I don't know how to change this for xfce4-volumed.
>
>
> On Wednesday, July 13, 2016 at 11:38:01 PM UTC-4, raah...@gmail.com wrote:
> > On Wednesday, July 13, 2016 at 6:27:41 PM UTC-4, Micah Lee wrote:
> > > On 07/13/2016 03:07 PM, Marek Marczykowski-Górecki wrote:
> > > > Wasn't that installed by default? It should be...
> > >
> > > It wasn't for me. I installed xfce by installing the @xfce-desktop-qubes
> > > package in dom0, rather than using the installer.
> > >
> > > > Install xfce4-volumed. It will be installed by default in next release
> > > > candidate.
> > >
> > > Thanks!
> >
> > did you figure out how to get your volume controls working.  I had same issue and installed the audio mixer from panel preferences, but haven't got the kb volume buttons working yet.