Dolby Digital and Digital Theater Sound (DTS) are two of the most common digital surround sound formats available, developed by competing companies. Dolby Digital audio is the more popular — your cable TV set-top box and streaming box likely use it as a default.DTS audio is more commonly found on DVDs and Blu-rays. Both Dolby Digital and DTS have advanced versions (including Dolby Atmos and DTS:X). If you’re a casual TV watcher, something that supports Dolby Digital would be more than suitable. If you’re a movie buff, look for one that supports DTS.