Mono Bridge

A method of configuring a two channel amplifier so that the two channels can be “ganged” or bridged to be used together on one load. The purpose of this is to take a two-channel amp and create a larger single channel amp that can deliver more power. It works by reversing the polarity of the signal going to one of the amp channels. The same signal is presented to both sides, but with opposite polarity. Then the load, which is presumably a speaker or set of speakers, is connected across the positive lead of both channels. The ground or negative leads are not used. So while the signal drives one of the hot leads in one direction (positive or negative) it will drive the other hot lead in the opposite direction in an otherwise identical way. This creates a difference of voltage between the two channels that is twice as great as either channel by itself referenced to ground, or the negative terminal. The result is more power to the speaker than would be possible from either channel alone. Most modern amps have a special switch to enable mono bridge operation. It basically takes care of the polarity reversal of the signal going to one side of the amp.