Patent ID: 8116465

Claim:
A measuring apparatus for use in an audio reproduction system having a loudspeaker, said apparatus comprising: impulse response obtaining means for obtaining an impulse response signal; positive transform means for performing a positive transform on the impulse response signal obtained by the impulse response obtaining means; low-pass filter means for filtering the impulse response signal on which the positive transform was performed by the positive transform means; frequency characteristic obtaining means for obtaining a frequency characteristic of the impulse response signal obtained by the impulse response obtaining means; filter characteristic setting means for setting a filter characteristic of the low-pass filter means so as to be variable depending upon the frequency characteristic obtained by the frequency characteristic obtaining means; and measurement result obtaining means for obtaining a measurement result about a predetermined measurement item based on a waveform of an output of the low-pass filter means, said predetermined measurement item being representative of a distance between a listening position of a user and the loudspeaker, and wherein an operation to measure the distance is based on signal processing of an impulse response to an impulse output of the loudspeaker, and wherein the predetermined measurement item is based on a comparison of a middle-frequency average dB value and a high-frequency average dB value.