| 摘要 |
PURPOSE:To display the state together with the frequency characteristics, by adding the circuit processing the speaker output signal and automatically operating the upper and lower amplitude ratio of great amplitude signal such as tone burst waves. CONSTITUTION:The tone burst wave produced at the tone burst generator 1 is amplified at the power amplifier 3 through BPF2, the signal is fed to the measured speaker 4 in the non-echo room L, and the sound waves from the speaker 4 are received at the microphone 5. The electric signal from the microphone 5 is amplified at the preamplifier 6 and the output is distributed into the paths i and j for processing. Further, the plus component of the amplitude waveform is picked up at the half wave rectifying circuit 13 of the path i and the peak value is detected at the peak value detection circuit 15 and fed to the division circuit 16. On the other hand, the polarity of the waveform is inverted at the polarity inversion circuit 11 of the path j, the peak value of the minus component of the amplitude waveform is detected at the half wave rectifying circuit 12 and the peak value detection circuit 14 and it is fed to the circuit 16, the ratio of amplitudes operated at the circuit 16 is fed to the level recorder to display the frequency characteristics together with the amplitude ratio. |
