The main performance of the International Electrotechnical Commission standard hi-fi headphones IEC581-10 is: not less than 50Hz frequency audible sound to 12500Hz; typical frequency response of tolerance ± 3dB; frequency response curve slope did not exceed octave 9dB at 250Hz-800Hz about units within the same octave band sound pressure level does not exceed the difference between the average 2dB, within the range of 100Hz-5000Hz, the sound pressure level of 94dB, the harmonic distortion is less than 1%, when no more than 3% 100dB; headset frequency response between 2KHz-5KHz allows decline, in order to improve transparency and sense of space.