I have a Sky Soundbox and was looking for advice on what best audio track should I create within my MP4's and MKV's when converting from DTS Audio to AC3 or AAC

I've got the headache that 300 plus movie files all with DTS audio will no longer play on my 2018 Samsung TV which no longer support DTS audio, so I've been converting the files with either Xmedia Recode, Handbrake or File Factory.

The AAC/AC3 output setting refer to various audio setups of Stereo and 2.1, 3.1, 4.1, 5.1 or 3.0, 4.0 or 5.0 I'm not sure if anyone knows which is likely to support the SoundBox or help me understand which are Dolby Digital as all I know is that the soundbox support Dolby Digital.