The information in this article can help when you are using a Bluetooth audio device (headphones, earbuds, speakers, etc.) connected to your Nintendo Switch, but the audio is too quiet or too loud.
What to do
Adjust the volume on your Nintendo Switch system using the Volume + and – buttons.
Many Bluetooth audio devices include their own volume controls which determine the audio output volume. Refer to the audio device’s instruction manual or manufacturer’s support to adjust the volume controls on the device.
Set the Lower Max Headphone Volume in System Settings to On or Off to either decrease or increase the possible volume output.
Situation not resolved
Bluetooth audio devices can vary in audio quality and possible volume. Try pairing a different Bluetooth audio device or using a wired audio device.