There are many types of speakers, and their performance parameters, caliber size, and range of use vary. The selection should be based on the specific conditions of use, not blindly pursuing high-power, large-caliber and other content. The speaker should be selected according to the occasion and the purpose of use.

1) When purchasing a loudspeaker, first check whether the nominal impedance and rated power marked on the loudspeaker's trademark are what you need; then make an appearance identification and observe whether the speaker leads are intact and the paper cone is damaged or broken ， Whether the pedestal is glued firmly and so on.

2) When checking the speaker, use both hands to gently press down on the paper cone to listen carefully to the rubbing sound of the voice coil and the iron core. Do not use excessive force when pressing the paper cone to avoid damaging the cone.

3) When the above content inspection meets the requirements, you can conduct audition inspection. Connect the speaker to the power amplifier circuit whose impedance and power meet the requirements. Listen for the hoarseness, harshness and other undesirable sounds from the speaker. The sound from the better speaker should be layered, full, harmonious, clear and beautiful , Have a sense of comfort. It is best to choose the music you are familiar with during the audition.