Impedance is the electronic measurement of a device's resistance to the flow of an AC signal, such as audio. It is similar to resistance, which indicates a device's resistance to the flow of a DC signal. Both impedance and resistance are measured in ohms.
When referring to microphones, low impedance is less than 600 ohms, medium impedance is 600 ohms to 10,000 ohms, and high impedance is greater than 10,000 ohms.
