While 'sound' is pretty much the same issue whether you are using Parallels RAS or not, there is one more volume control adjustment that can stymie users.

1. Check that the volume setting of the speakers
   1. built-in monitor speakers
   2. set both monitors' volume to 100%
   3. this is harder than it sounds because monitors are all different
   4. you can skip step 1 and move on to steps 2, then 3, only returning to step 1 if unsuccessful
2. Check the volume setting of your workstation
   1. not the remote session with blue bar at top
   2. set it to 100%
3. Finally, check the volume setting in your remote session
   1. blue bar is at the top
   2. QM Desktop remote session
   3. set volume to 100% initially
   4. adjust to your desired volume here after it makes sound

The above applies to low volume issues, as well as no sound issues.