See also: Offset Wizard and Universal offset
If the hitsounds feel out of sync with the music in every beatmap you play, you will more than likely need to change your universal offset. The easiest way to do this is by using the Offset Wizard.
Follow the following steps to adjust your universal offset using the Offset Wizard.
Optionsmenu, or press
The Offset Wizard will then open, playing the song that was previously played in osu!, while green bars scroll across the screen and a metronome is ticking.
Backbutton at the bottom left of the screen to exit the Offset Wizard.
If the metronome feels too fast or too slow for the song, you may want to enable either
Half tick or
Double tick in the top left of the screen to make things easier.