Make Same user in multiple Xservers not share audio.

OS: Linux Mint 17.1 based on Ubuntu 14.04.
DisplayManager CDM running in the same usermode for every x-login.
I am running two wms in separate xservers on different ttys (tty7 ad tty8).
I am running Xorg with user-rights set to Everyone

dpkg-reconfigure x11-common

Choose 'all'.

I have added myself to group audio

 sudo usermod -a -G audio username

The problem is that when I switch to another tty where X is running I also hear sound from the previous tty.
My question - how can I turn sound off from the tty I am switching _from_ and on at the tty I am switchin _to_ .?
Also - is it possible to put the previous Xsession, movies, music youtube etcetera - in a paused state.?
Also 2 - is there a way to automatically 'unpause' the Xserver when I swithch back to that tty.?
For the moment I am using Fvwm att tty7 and pekwm att tty8 .
Logging in as different users is _not_ a preferable option.