Sony Mobile has enhanced the audio capabilities of the Xperia XA2 and Xperia XA2 Ultra, by officially enabling high-resolution audio and DSEE HX in the latest firmware update (build number 50.1.A.13.83).
DSEE HX (Digital Sound Enhancement Engine) upscales your existing audio to near high-resolution quality, while high-resolution audio requires the use of a compatible headset. Seems like a decent update for Xperia XA2 and XA2 Ultra owners.
Via Sony Mobile Blog.
Thanks Takuya!