Abstract: An audio loudspeaker protection circuit used to protect single or multiple array connected audio transducers, and passive audio crossover networks from damage. An audio loudspeaker protection circuit providing protection during power overload, high speed transients, or direct current. This circuit has an adjustable activation control that accommodates broad power ratings for audio transducers, irrespective of the total load impedance. No sound coloration, dynamic range, or frequency response losses are added when implementing this circuit. This is due to high impedance, and low capacitance design. Virtually no power is consumed during normal audio system operation. The circuit is able to activate with any audio or non-audio signal, regardless of signal input polarity. The circuit comprises of several elements consisting of two high-speed rectifier circuits, a threshold detect circuit, a thyristor crowbar circuit, a relay, and a relay coil current regulator.