Depending on the connected device or its settings, the audio output format of the connected device may not be in Dolby Digital or DTS, even though the unit is in the HDMI mode.
Check the following.
- Make sure your DVD / Blu-ray player or TV support output is in Dolby Digital or DTS
- Make sure that the audio output settings of the DVD / BD player or TV is set to something other than Pulse Code Modulation (PCM)
- Make sure the content compatible with Dolby Digital or DTS