At present, Bluetooth function has become a frequently used function in people's daily life and is widely used in smart phones, smart televisions (TVs) and other terminal devices. Among the devices, Bluetooth speakers and earphones are the Bluetooth audio devices which are much more commonly used, and the most of requirements for the audio devices from users are sound quality and volume. A smart TV of which has a Bluetooth function, its volume adjustment becomes more complicated because the TV itself has a volume adjustment function (only for the Bluetooth channel), and the Bluetooth audio device also has its own volume adjustment switch.
Currently, to the smart TV with Bluetooth function, when being successfully connected with Bluetooth audio device, the Bluetooth volume can be adjusted by: the user adjusting the Bluetooth channel volume of the TV (via a remote control or a keypad's volume up/down). By this adjustment, the volume's gain value controlled by the TV's IC is adjusted, that is, the volume of the sound sent out by the TV is adjusted. If the volume of the Bluetooth audio device at this time is very small, there will be a limit to the volume change of adjusting the TV, and the range of volume change is small, so the user further needs to manually adjust the volume of the Bluetooth audio device, which results in a poor user experience.
In addition, the above-mentioned volume adjustment method still has a defect: when the volume of the Bluetooth audio device is at the maximum value (max), after the TV is connected to the Bluetooth audio device, adjusting the volume gain of the TV through the volume key is prone to cause a distortion.