Without model numbers we can't know what connections you have.
In general there are two ways.
1. Connect the box to the TV with HDMI. Connect the HTS to the TV with either HDMI-ARC or optical audio.
2. Connect the box to the HTS with HDMI. Connect the HTS to the TV with HDMI.
If you have other sources they would connect the same way. If you have sources that can output lossless audio like Dolby TrueHD they need to be connected to the HTS with HDMI. Check the TV and HTS manuals on how to turn on the TV audio output and how to assign the audio connection from the TV to an input on the HTS.