I have a Zvox 450 and wish to control my sound control thru my Roku remote.
When I spoke to Zvox about this problem I got the following reply from their tech.
"I don't believe that would be possible with the Roku TV system. Their remotes with voice control all work over RF. The Chromecast with Google TV would give you voice control and it has a system for controlling sound systems which includes ZVOX devices, as do the Amazon Fire Sticks.
Is there no way, to have the Roku control the sound from my Zvox sounder?
Launch or hide Live TV Channel Guide  “open live TV guide” “open channel guide "hide channel guide"
Adjust volume levels  "turn the volume up" "volume down" "mute" "set volume to 50%" "set volume to 5"
 You cannot use voice commands to switch to a device you have assigned a custom name  You must have an HDTV antenna connected to your Roku TV to use voice commands to change over-the-air broadcast channels and launch Smart Guide. Requires HDMI-CEC support on your TV.
Your soundbar only supports Optical/Coaxial SPDIF and analog inputs (it lacks HDMI).
You'll need to upgrade/replace your soundbar with one that has HDMI w/CEC in order to use the voice volume control feature.