Sound playback of normal voice signal strength and the ratio of intensity of noise signal

Refers to the normal sound playback voice signal strength and the ratio of intensity of noise signal. Low signal-to-noise ratio, small signal when the input noise is serious, in the whole range of voice grew noticeably muddiness, blare blare du not hair what sound, very affect the sound quality. Signal-to-noise ratio is less than 80 db speakers, less than 70 db bookshelf speaker doesn't suggest to buy! Sensitivity (dB) : this refers to produce full power output when the input signal, the lower the input signal, the higher the sensitivity. Poor speakers, the sensitivity of each 3 dB, the output sound pressure differs twice, with 87 dB sensitivity, commonly below 84 dB for low sensitivity, above 90 dB for high sensitivity. And the improvement of sensitivity at the expense of the distortion degree increase, so as a high-fidelity speakers, to ensure the reduction degree and representation of timbre capacity will have to reduce some claim to the sensitivity. Sensitivity is an indicator of speakers, but it has nothing to do with the speaker sound quality tone. "Active speaker" of the "active" active speakers is a signal processing circuit, control circuit and power amplifier speakers. Active speaker can directly with the general audio source (such as the bookshelf computer speaker, CD, VCD, VCR, computer sound card, etc.) are tie-in, form a complete set of sound system. With active speakers, there is no need to purchase another power amplifier, also do not have to worry for power amplifier, speakers of reasonable collocation. Active speaker has a very high cost performance, due to the active speakers built-in amplifier circuit, make the attachment much shorter than the outer power amplifier, is much more simple, small 巵 talk, background noise. Active speaker with built-in amplifier, can greatly save household space. Active speakers, simple operation, only some necessary switches and adjusting knob on the box body, remove the other power amplifier on practical operation knob, not can only simple to open the power switch can be. Special SOUND technology hardware 3 d SOUND technology is now mostly use of SRS, APX, Spatializer 3 d, Q - SOUND, Virtaul Dolby * and Ymersion several, although their application theory is different, but they can make a person feel obvious three-dimensional acoustic field effect, the first three are more common. And there are two kinds of audio enhancement technique: active mechanical and electrical servo technology and own empowerment, high-definition plateau sound playback system, to improve the sound quality also to have certain improvement effect.