If you launch True-Fi and there is no sound coming out of your headphones, make sure that your audio device is properly set up for audio playback and connected to your Mac. Then check these settings -
1. Sound Preferences:
In this menu, True-Fi has to be set as your main output device, since all audio will be routed through calibration
2. True-Fi audio settings
Here you'll need to set the main listening device as your Output device, since True-Fi has to know where to route the incoming audio to
Click the bell icon to see if you've selected the correct output device. If you still are experiencing playback issues, please write to support for further assistance.
There are also some media players, like JRiver and iTunes where you'll need to specify in their internal settings that True-Fi will be used for media playback!