I had to write two events per audio type. One tracks the changes in audio type from the MX160 (e.g. DTS:X MA, 7.1.4), but instead of actually executing the needed MX160 post processing command, it instead just updates a state variable/key to what that changes was (e.g. DTS:X) . The second event tracks changes in that key/variable (DTS:X in my example) and executes the post processing command that I want. Since I have no events written for "no information" MX160 audio type, the post processing command doesn't execute again unless there was a real audio type change. Seems to work really well. I'm constantly switching post processing depending on the movie (e.g. Dolby Atmos I want set to NONE, but for DTS MA formats I liked to use DTS Neural:X). One less thing to think about! SJ