Hmm, why would you want to do that? Dirac HD is for headphones while built-in speaker and its quality are what they are. If it was enabled with the small loudspeaker of the phone the audio would become unclear and uncrisp - because it’s already factory tweaked to it’s optimal sound quality settings. If you really want good quality, buy some good in-ears (you can start off with xiaomi piston, theyre around 20e) maybe and just don’t use the built-in loudspeaker when looking for a great listening experience - it just isn’t made for that. ;)
Adjusting Dirac HD and EQ can be done in real time, with music playing on the background.