Sound system's main technical indicators
Technical indicators for the overall audio system performance, advantages and disadvantages, depending on the performance of each unit's own good or bad, if the system in each unit's technical indicators are high, then the overall system of technical indicators are very good. There are six of its technical indicators: frequency response, signal to noise ratio, dynamic range, distortion, transient response and stereo separation, stereo degree of balance.1, frequency response: the so-called frequency response refers to the audio playback device when the magnitude of the frequency range and sound relationship with the frequency changes. General detection of this indicator in order to 1000Hz frequency range as a reference, and use of tens of decibels (dB) as a unit, said frequency range.Sound system's overall frequency response theory calls for 20 ~ 20000Hz. In practice, due to the use of circuit structure, component quality and other reasons, and often can not meet the requirements, but in general to reach at least 32 ~ 18000Hz.2, SNR: signal to noise ratio is the so-called audio system on the audio software re-aloud with the entire system to produce a new noise ratio, the noise mainly thermal noise, communication noise, mechanical noise and so on. General detection of this indicator in order to replay the rated output power of the signal and the non-signal input system noise output power ratio of the number of decibels (dB) to represent. Generally sound system for more than 85dB signal to noise ratio are required.3, Dynamic Range: Dynamic range refers to the sound system playback without distortion when the maximum output power and static, the system noise output power ratio of the value, units of decibels (dB). Generally better performance of the audio system's dynamic range is 100 (dB) or more.4, Distortion: Distortion is the sound system right after the audio signal playback, so that some parts of the original audio signal (waveform, frequency, etc.) has changed. Distortion of the sound system is mainly in the following categories:a. Harmonic Distortion: The so-called harmonic distortion is the sound system playback sound after the signal source more than the original number of additional harmonic components. Additional harmonic components of this signal is the signal source frequency multiplier or divider, it is a negative feedback from the network or caused by amplifier nonlinearity. Hi-fi system, harmonic distortion should be less than 1%.b. Intermodulation Distortion: IMD is also a non-linear distortion, which is more than two frequency components by a certain percentage of mixing among the various frequency signal modulation, through the playback device to generate new non-linear increase in signal, This signal includes the various signals and and the difference between the signals.c. Transient Distortion: Transient distortion known as transient response, it is mainly generated when a sudden large transient signals due to the amplifier when the amplifier added to reflect the slower, so that the signal distortion produced. Generally square wave signal input through the playback device, observe the amplifier output signal envelope waveform is the input square wave waveform amplifier similar to express the ability to follow the transient signals.5, stereo separation: stereo separation, said stereo sound system in the left and right isolation between the two channels, it actually reflects the left and right extent of crosstalk between two channels. If the two-channel cross-talk between the larger, then the replay will be weakened sense of three-dimensional sound.