Speaker impedance is the resistance to the flow of electrical current presented by a speaker to an amplifier. It is measured in ohms. The impedance of a speaker affects how much electrical power it draws from the amplifier and how it interacts with the amplifier’s output stage. Mismatched impedance between the amplifier and speakers can result in poor power transfer, distortion, and potential damage to the equipment. Matching the impedance ratings ensures optimal performance and longevity of both the amplifier and speakers.