What does DiracHDsound mean in OPPO mobile phone player? Besides, what's the sound effect? Which one to turn on when listening to music?

Dirac HD audio? It is not a sound effect, but an audio fidelity technology jointly developed by Dirac Res earch AB and Uppsala University in Sweden, which can fundamentally improve the sound quality by optimizing the performance of the sound system, enhancing the restoring force of the system. Specifically, this proprietary technology can optimize the transient response and frequency response capability of the sound system, optimize the performance to the physical limit allowed by the system, and improve the sound quality. This patented technology can fundamentally improve the sound quality and restore the original sound as much as possible, which is essentially different from the sound effect and equalization technology.