Follow any or both steps below (good for all Oneplus 7 series).
STEP 1: Fix stereo imbalance (ROOT is required)
The top loudspeaker sounds louder and crispier than bottom (moreover, the top rattles more at high volume). This can be fixed by editing dax_sqlite3.db with any SQLite editor:
1. Open dax_sqlite3.db and go to "tunings".
2. Open record with "speaker_landscape_normal" and edit 2 parameters, then save.
- Replace audio_optimizer_gain_l with new value:
- Replace audio_optimizer_gain_r with new value:
4. Reboot. That's it!
If something goes wrong (or you dislike new sound), just remove dax_sqlite3.db and reboot. Dolby will re-create it and return all default settings. Details about this edit:
So we reset both EQs to sound equally neutral, but keep the top speaker ~2 db lower.
STEP 2: Enable graphic EQ for speakers
You can activate dolby atmos equalizer for loudspeakers (available only for headphones by default) to get more bassy and clean sound.
If you don't have ROOT, use this DAX2 app: https://forum.xda-developers.com/one...-root-t4054999
You will have to disable/freeze built-in dolby tuner for full functionality (see tips also in that thread).
If you have ROOT, I recommend the method below. It relies on internal dolby app and will work in all modes (dynamic/movie/music + ringtone).
You'll need to edit sound_tuner.db with any SQLite editor:
1. Open sound_tuner.db, then go to "sound_tuner" and edit the line with "speaker_device".
2. Change values for "headphone_style_preferred" ("Intelligent style") and "audio_frequency" (EQ itself), then save changes.
- headphone_style_preferred keeps value from 0 to 3 (0 - balance, 1 - warmer, etc), "0" is recommended.
- audio_frequency keeps a string with each band gain in dB, separated with '#' without spaces. Recommendation for 7T:
To reset EQ you can return "0#0#0#0#0#0#0#0#0#0" in "audio_frequency".