Abstr: what is bridge? Bridge is a connection mode of power amplifier in professional audio field -- bridge mode.
What is bridging
Bridge mode is a kind of connection mode of power amplifier in professional audio field.
In short, power amplifier bridging is to push a group of loads (speaker or speaker system) at the output of two amplifier lines at the same time. Improve the audio frequency of the amplifier without distortion of the output voltage value, so as to improve the power.
When the bridge is connected, the output audio waveform of the two amplifier lines is reversed and loaded on the loudspeaker at the same time, so that the load has twice the audio voltage, thus the power is increased by four times (when the ideal current is enough, and the load impedance is consistent). However, due to the power limitation, the current cannot keep up with it. Therefore, the bridge is not suitable for impedance lower than 8 Ω, so the output power is usually doubled. )
Most professional performance amplifiers and KTV amplifiers support bridging mode. When the amplifier is switched to the bridge mode (BTL), the speaker does not need to be grounded (the black negative terminal is empty connected). The speaker wiring is jumper connected to two red output stages, and the phase is marked with the bridging phase (i.e. positive and negative poles).
Why bridge?
1. Due to the limitation of component parameters in early power amplifier products, single channel can not achieve high power output, so bridging mode can alleviate the desire for high power output;
2. When the single channel power of power amplifier is not enough to promote large-scale speakers (such as dual 18 inch subwoofer), bridging mode is needed to meet the needs of high-power speaker;
3. In order to save the cost, the higher the single channel power amplifier is, the more expensive it is;
4. When there is a certain distance between the field wiring, the number of speakers is large and the power demand is large, and the environment is relatively special, the bridge mode will also be used to promote multiple high-power speakers.
