First, the frequency response is appropriate around 150Hz ~ 10KHz. This range basically includes the vocal and general musical instrument sound.
Second, the sensitivity cannot be too high. Too high sensitivity is easy to produce howling or the phenomenon of large or small sound, and easy to damage the speaker, so the stable sensitivity is OK.
Third, the impedance is high and low, the high-impedance microphone has high sensitivity and is vulnerable to external signal interference.
Fourth, choose a microphone with directionality. Since the non-directional microphone has poor resistance to external interference and is easily mixed with other sound sources, this microphone must be used in conjunction with an echo canceller.