Because "DTS" can refer to the audio format or the company behind it, the situation depends on what you are trying to do.
Generally free . If you have an Xbox or a Windows PC and a compatible soundbar or receiver, you can use the DTS Sound Unbound app to enable home theater passthrough at no extra cost. is dts free
This uses software to simulate a surround-sound environment in any stereo headset. While there is a 14-day free trial , continuing to use it requires a one-time purchase. Because "DTS" can refer to the audio format
If you just want to play a movie file (like an MKV or Blu-ray rip) that has DTS audio, you do not have to pay DTS money, but you need software that supports it. This uses software to simulate a surround-sound environment
Be careful if you search for "DTS encoder free download" online. Many websites claiming to offer free encoders are often malware or pirated software that can harm your computer. Stick to trusted media players like VLC or PotPlayer for playback.