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Between mike and mike preamplifier match
From;    Author:Stand originally
In mike and preamplifier application domain, "Impedance matchs (ImpedanceMatching) " it is the topic that an existence misunderstands extensively. Because in fact, great majority mike and great majority preamplifier, mutual between can form more satisfactory combination, need to undertake far from alleged " true " impedance matchs. As to " impedance matchs " of the problem put forward, going after some to plant to the utmost only specific acoustic quality, tone, chromatic (Coloration) and when the characteristic, ability can become significant.

Before explaining this problem in detail, we explain what is impedance first. We know, an any mike contain output impedance inevitably, and words of any the one buy before the paragraph put inevitable also region to have input impedance. What say here " impedance " those who point to is signal electric current what encounter when pouring out of circuit of preamplifier of mike circuit, flow direction " resistor " .

Because impedance is used normally " Z " will express, consequently, the term that arose to use a description technically to input output interface -- " Hi-Z (tall impedance) " (guitar hand should be compared to this vocabulary familiar) . In applying actually, the input impedance that buy word puts before will be right the sound effect that inputs signal produces major effect. Because,this basically is, the output impedance of mike and before the interaction between the input impedance that buy word puts affects a relation each other, the final result that can give sound signal brings major change, different sound is balanced effect, for instance different go up to be waited a moment to the characteristic. Be told further even if, the interaction between the inputs impedance to be the same as different mike input impedance that word of the buy before differring puts also is different on means and degree.

We are used below the spray head that carries before used pipeline and conduit waters to make an example in the garden. Mike is just like is conduit, belong to low impedance source, that is to say, the resistance when current is ongoing is less; And before buy word is put be just like is nozzle, impedance is very tall. Above all, if we put out the valve of nozzle, input obstruction (before the input impedance that buy word puts) can increase quickly, hydraulic (voltage) also can rise suddenly to maximum, at this moment, the discharge of the current in nozzle (electric current) turn into 0.

Next, if we open valve the word of a bit a little again, input obstruction and current pressure can change accordingly small (although as before very big) , current also begins to appear, but, at this moment nozzle can be given out " whistle whistles " sound (high frequency) . Later, as nozzle valve leave ceaselessly big, input obstruction and current pressure begin to drop ceaselessly, the discharge of current also begins to increase continuously, at this moment, "Whistle whistles " sound can begin to disappear gradually. From inside this example, we can discover, the impedance that buy word puts before is lower, the high frequency part of sound signal can become more unidentified show.
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