Intelligent Controls Oriented Audio Analyzer

Audio analysis is widely used to measure time domain, frequency domain and distortion characteristics of various audio system. An all-around audio test and analysis needs all kinds of expensive special instruments, which should be well organized. Obviously, it is not a piece of cake for common user. And the Intelligent Controls-oriented Virtual Instrument is a fire-new model in development of measure instrument. It bring a fire-new appearance to audio analyzer that using the technology of Intelligent Controls-oriented Virtual Instrument in the manufacture design of it.The paper introduces the general ideal of Intelligent Controls-oriented Virtual Instrument What the ideal is that intelligent cells of instrument can compose various instruments, and can show them to user on PC, which are derived from virtual controls by combine virtual control and functions of instruments through functions endowing. The intelligent cells of instrument named Intelligent Virtual Controls is a kind of living virtual part endowed instrument functions, which describe the appearance and the essential of Intelligent Controls-oriented Virtual Instrument.The contents, purposes and methods of audio analysis are studied in this paper. In Amplitude Analysis in time domain, the step impulse response acts as an important parameter to evaluate the performance of audio device. It reflects the response sensitivity of audio system to sudden changed signals. Audio devices' performances in playback are evaluated by their frequency response in the whole audio frequency range. There are several widely used methods to acquire the frequency response graph, including single tone method, multiple tone method, noise impulse method and Maximum Length Sequence signal impulse method. The last method, MLS signal impulse, has so obvious predominance in the aspect of decreasing noise as to obtain increasingly wide use. Harmonic distortion is one of the most common non-linear distortions, and it affects the playback performance of audio devices directly. Harmonic distortion graph reflects the distortion distribution in the whole audio frequency range.Adopting Intelligent Controls-oriented Virtual Instrument, Structured Design thought and software bus thought synthetically, the article introduced the constitution of intelligent controls-oriented audio analyzer, built the apparatus, and implemented the functions in the developing system of VMIDS. The layer of function provides versatilemeasure and analysis functions to meet the requirement of audio devices, including measure of audio signal's volt, frequency and distortion, Amplitude Analysis in time domain, Amplitude Analysis in frequency domain, analysis of distortion, etc. The layer of denotation was implemented by the building field .The loudspeakers of sound box are tested using virtual audio analyzer, and some audio characteristics are obtained...