TP-Link UB400 Quick Start Manual page 17

5) Hit OK, then restart your machine.
For Windows 7 users:
Go to Control Panel > Hardware and Sound > Manage Audio devices > Right-
click Bluetooth Audio Renderer; go to the Advanced tab, and set the Quality to DVD.
Q11: Audio is intermittent when listening to music
Please remove the Bluetooth headphones from devices. (Right click on the Bluetooth symbol in
the lower right corner of the desktop and select Show Bluetooth Devices. And then in
the Audio section, you will find the headphone that has already been connected. Please
click Remove device)
Then re-pair the headphones and add them back as a device. Sometimes you must do this a
couple of times and then the audio starts smoothly playing music and streaming video.