Connection diagnostics for parallel speakers

摘要

Connectivity of a pair of parallel electroacoustic transducers is determined by applying a first test signal on the output line at a frequency where the impedance of the transducers in parallel is less than the impedance of the higher-frequency transducer alone, and observing whether a clip signal is received. If the clip signal is not received, an error indication is output. A second test signal is applied at a frequency where the impedance of the transducers in parallel is less than the impedance of the lower-frequency transducer alone. If the clip signal is not received, the error indication is output. A third test signal is applied at a frequency where the impedance of the transducers in parallel is higher if both transducers are operational than if the higher-frequency transducer is internally short-circuited. If the clip signal is received, a third error indication is output.

主权项

1. A method of determining connectivity of a pair of electroacoustic transducers comprising a higher-frequency transducer and a lower-frequency transducer which are connected in parallel on an output line of an amplifier, the method comprising:
causing the amplifier to apply a first test signal on the output line at a first test frequency where the impedance of the two transducers in parallel is less than the impedance of the higher-frequency transducer alone, observing whether a first clip detection signal is received from the amplifier, and if the first clip detection signal is not received from the amplifier in response to the first test signal, outputting a first error indication and stopping; otherwise, if the first clip detection signal is received from the amplifier in response to the first test signal, continuing by causing the amplifier to apply a second test signal on the output line at a second test frequency where the impedance of the two transducers in parallel is less than the impedance of the lower-frequency transducer alone, observing whether a second clip detection signal is received from the amplifier, and if the second clip detection signal is not received from the amplifier in response to the second test signal, outputting a second error indication; otherwise, if the second clip detection signal is received from the amplifier in response to the second test signal, continuing by causing the amplifier to apply a third test signal on the output line at a third test frequency where the impedance of the two transducers in parallel is higher if both transducers are operational than if the higher-frequency transducer is internally short-circuited, observing whether a third clip detection signal is received from the amplifier, and if the third clip detection signal is received from the amplifier in response to the third test signal, outputting a third error indication.