Audio Precision音频分析仪测试介绍

1、ap introduction meanwhile the other channel is set for zero volts. the measured channel left open. - whatever signal is induced into the tested channel is measured at its output with an rms voltmeter and noted. a ratio is formed by dividing the unwanted signal by the above-noted output test value, a

2、nd the answer expressed in db,ap introduction,harmonic distortion concepts - harmonic distortion may be measured and expressed as total harmonic distortion (thd), or as total harmonic distortion plus noise (thd + n). - thd is the distortion that occurs on harmonics of the original signal. noise is t

3、he more random, uncorrelated distortion. - in all cases, stimulus from a very pure sinewave generator is fed to the input of device under test. the generator must have significantly lower distortions than that of device,ap introduction,harmonic distortion concepts - thd refers to measurement methods

4、 which individually measure the amplitude of each significant harmonic in a narrow bandwidth, then combines them in root-mean-square fashion to produce a single number. - thd + n, refers to the measurement technique in which the fundamental component is removed by a bandreject (norch) filter and all

5、 remaining energy measured, including harmonics and noise,ap introduction,harmonic distortion concepts - bandwidth and thd+n the measured thd+n of a device will vary with the measurement bandwidth. you will almost always want to restrict the measurement bandwidth using high-pass and low-pass filters

6、, and you must include the bandwidth used when you state the result. thd+n is typically measured and reported in a 20 hz20 khz bandwidth,ap introduction,harmonic distortion concepts - level and thd+n the measured thd+n of a device will also vary with level and the frequency of the applied signal. au

7、dio thd+n is typically measured and reported at a mid-range frequency (1 khz or so) at the either the devices nominal operating level or at its maximum output level (mol). - a thd+n versus frequency sweep or a thd+n versus amplitude sweeps will show how a dut performs under varying stimulus,thd + n,headphone output,thd + n,thd + n vs level,thd + n,thd + n vs le