Patent ID: 7813514
Filing Date: 2010-10-12
Classification: H04R

Abstract:
1. A loudspeaker checking apparatus comprising: a signal generating unit configured to generate a test tone signal by adding first and second sinusoidal signals of different frequencies; a control circuit configured to allow the signal generating unit to generate a plurality of test tone signals by varying the frequencies; an output circuit configured to simultaneously supply the plurality of test tone signals to a plurality of loudspeakers, respectively; an analyzing unit configured to perform frequency analysis on an output signal from a microphone that picks up test tones output from the plurality of loudspeakers; and a determining unit configured to determine whether the respective loudspeakers are normal or abnormal on the basis of an analysis result made by the analyzing unit, wherein the signal generating unit includes: a memory storing digital data representing one cycle of a sinusoidal signal; a first generating unit configured to generate the first sinusoidal signal having a frequency x times that of the sinusoidal signal by reading the digital data from the memory every x samples, x being a natural number; a second generating unit configured to generate the second sinusoidal signal having a frequency y times that of the sinusoidal signal by reading the digital data from the memory every y samples, y being a natural number different from x; and an adding circuit configured to add the first and second sinusoidal signals so as to generate the test tone signal.