how to get a video with DTS sound working with headphones (1 Viewer)

[rjamesbeen]

I would like to switch from HDMI sound output to headphones at times with two babies sleeping upstairs. However when having to manually switch audio output to 'Speakers (Headphones) what is a little annoying I am not able to play a DTS sound source. Most other videos will play without problem. I am not able to make it work even with various changes of settings within Mediaportal. At the end I have to play the video with an external player which is frustrating for a mediaportal fan as I am.

Any ideas how to make DTS work with my headphones within mediaportal with the least of effort?