Power amplifiers are a type of amplifier that tends to supply power to one or more speakers. They usually come in multiple channel configurations, right from one channel to two channels. Power amplifiers are likely to feature multiple channels, from five to seven, or even more, for surround applications. If nine channels are required then both two and seven channel power amplifiers can be employed. In case eleven channels are needed then a seven-channel amplifier tends to be teamed with two two-channel amplifiers. A monoblock amplifier might additionally be used for each channel, which calls for a lot of amplifiers.
A separate preamplifier or an AV preamplifier/processor is essential to transmit audio signals to a power amplifier. The AV preamplifier/processor is responsible for decoding or processing audio source signals and then relaying them to the power amplifier. Subsequently, the power amplifier delivers these signals to the speakers. The transmission of signals occurs either in analog form through line outputs with RCA-type connections or, in more high-end preamplifier/power amplifier combinations, via XLR connections. In the context of home theater setups, it's advisable to include a subwoofer alongside source devices and speakers. If the subwoofer is self-powered, it comes equipped with an internal amplifier. To channel sound to a powered subwoofer, simply connect a provided subwoofer preamplifier output from an AV preamplifier/processor or a home theater receiver.
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