Dolby EX

[Enigmatism]

What is the difference between DolbySurroundEX and DolbyDigitalEX?

Does DolbyDigitalEX replace the DolbyDigital track on DVDs, or is there a special track for it?

[Hi Ho]

They are both the same. They are both digital. The "EX" track adds an extra channel for 6.1. It doesn't replace the 5.1 track.