... etc.2: amplifiers, frequency response has stable performance, low power consumption, two advantages of lithium battery electric batteries, use ... host 1 and 2 li-ion battery cells, braces, power adapter, a manual. Second, the technical parameters: Frequency response150Hz-15kHzStandard ... the following questions, please replace the battery:1>.the power indicator does not shine.2>.microphone voice.3 >. ...