1. While using your P100 headphones with a wired connection, disconnect any connected Bluetooth devices from the P100s.
2. If you are connecting the headphones to a Mac or PC via a wired connection, ensure that the P100s have been selected as your output speaker within your Mac/PC's settings.
3. Ensure the volume on your source device and the app used to play audio isn’t muted or turned down too low.
4. Reset any custom or preset EQ settings that may be configured.
This includes any settings in the Melomania Connect App, for the device itself and the app used to play audio. EQ settings may alter the sound of your P100 headphones.
5. Perform a factory reset on the P100.
You can perform a reset on the headphones by following the steps here.