A speaker horn driver is an important component of all loudspeaker systems. Horn drivers are commonly used to boost high and low frequencies, depending on the individual speaker cabinet's design. A blown horn driver can mean a weak frequency output, and can cause your loudspeaker to sound weak or unbalanced. Testing the horn driver allows you to determine whether the horn is blown or not.
Unplug any audio or power cables from the loudspeaker. If the speaker is self-powered, allow several minutes for the cabinet to cool down.
Determine how your speaker cabinet is held together. Remove any screws or bolts fastening the speaker cabinet's back panel in place. Remove the back panel to reveal the wires and connectors inside the cabinet.
Purchase a speaker tone generator. This is a metered device used to test electronic audio components. Reach inside the speaker cabinet, and trace the speaker wires going from the main speaker to the speaker horn inside the cabinet.
Attach the tone generator's black alligator clip to the exposed portion of the horn's black wire. Turn on the tone generator, and listen to the horn driver. If no sound comes out, your horn speaker is blown.