... , MP4 audio player. Output:5V, ≤450mA;Power:2W;Impedance:8Ω;Frequency response: 130Hz-14KHz;Audio input methods: External audio ... and process. KT-SP303Output:5V, ≤450mA;Power:2W;Impedance:8Ω;Frequency response: 170Hz-16KHz;Audio input methods: External audio ... source;KT-SP202 Output:5V, ≤450mA;Power:2W; Impedance:8Ω;Frequency response: 170Hz-16KHz; Audio input methods: External audio source ...