Most HTIB speakers should not be used with a regular receiver. HTIBs usually have 3 ohm speakers and will cause most receivers to work too hard. Most receivers want 6-8 ohm speakers. Plus, HTIBs usually have passive rather than powered subs. So, check the specs of your Panasonic speakers to determine whether they are suitable for re-use.
As for your current situation, the BD player will send TrueHD tracks as DD 5.1 at the maximum 640k bitrate and will rival lossless in quality. Since your system can't decode DTS, you have to set the player to PCM, which means you will only get stereo since optical doesn't support multichannel PCM. You can apply a mode such as PLII in the sound system to generate multichannel audio. But, it won't be discrete 5.1.
Last edited by BIslander; 09-05-2014 at 06:13 PM.