In most cases, if a speaker (or part of the speaker) has stopped emitting sound, a problem has occurred with the driver rather than the crossover network.  The easiest way to establish the fault for sure is to swap the driver with that of another speaker. If the fault follows the driver then the driver is clearly at fault, however, if the fault stays with the cabinet then you may have a crossover failure. For more information, please submit a query to a member of our support team.