Tell app to lower volume Is it possible to tell a specific app to lower volume, using intents? 
I would like to be able to use Tasker to tell the HEOS app to lower the volume.

EDIT:
Heos is a streaming system, controlled through an app. When the music is playing, and my phone is on the same wifi, I can control the volume of the system by opening the app and pressing the volume rockers. 
But it is rather cumbersome to open the app each time, so I was hoping to create a custom widget to do this instead.
Volume is system wide and not application wide, unless an application has it's own volume management, meaning there won't be a bulletproof proof solution, only application specific solution.

System wide volume can be altered on settings.db.