There is a way to use SRS Enhancements in other apps. I'm using Spotify nicely with SRS on
First start your app you want to listen to music (or anything) start the music playing.
Then click on home and open htc's music.
Start a song, you'll notice the EQ/SRS enhancement turning on (whatever you have set to on in the audio preferences within HTC music).
Then stop/pause the htc music playback.
Voila you have SRS ehancement with Spotify or anything else, untill you unplug your headphone or the HTC music app/process is killed.