What are prescaler
Because almost all the speaker now by many elements of the replay frequency points, so there must be designed a kind of device, can deliver the whole frequency amplifier, according to the need for music signals into high output, bass, alto, or high output, with corresponding to the bass speaker unit is connected, prescaler such device. If the whole band signal does not add to directly into the distribution of high, medium and woofer units in frequency, in that part of the outside the scope of "redundant signals" normal band signal reduction of adverse impacts, and may even make treble, mediant unit damage. From the circuit structure, prescaler essentially consists of capacitor and inductance coil form a partial list of LC filtering network, treble channel is it only make high-pass filter, the high frequency signal through the low frequency signal and resistance, Just want to reverse the bass channel, it is only through the bass and resistance to high frequency signal, The mediant channel is a bandpass filter except one, two points between high frequency hopping through frequency components and low, will be stopped. In the actual prescaler, sometimes in order to balance between high and the sensitivity of a woofer, join decay resistance, In addition, some prescaler also joined by resistor, capacitor compensation networks of impedance, its purpose is to make speaker impedance curve, so some psychological flat amplifier drive.