After posting Samsung i8910 HD Omnia Codes i'll focus on some "must of" mods and improvement that every Omnia HD's user should have to do to get the most of this very powerful smartphone :

How to fix the High pitched hiss on recorded video?

- In the "secret" menu: *#0002*28346#
- Press 3 "Records"
- Press 4 "CamcordAMR_AMR"
- Modifie the first value 1 "Tx MicAmp" from 30 to 12 (Type 12#)
- Then select Back -> Back -> Back --> 6 "Back-Up"

- In the "secret" menu: *#0002*28346#
- Press 2 "Play Sound"
- press 3 "Mp4 LoudSPK"
- Now change 4 "PreDR Gain" to = 6db. (Type 6#)
- Then select Back -> Back -> Back --> 6 "Back-Up"

- In the "secret" menu: *#0002*28346#
- Press 2 "Play Sound"
- Press 2 "Mp3 HeadPHN"
- Now change 2 "Coarse gain" to 6db (Type 6#)
- Then select Back -> Back -> Back --> 6 "Back-Up"