Electronic devices that boost the power of audio signals in a vehicle's sound system. They take the low-level signal from a head unit or other audio source and increase its voltage and current, allowing it to drive speakers with greater power and clarity. Amplifiers are essential for achieving higher volume levels, improved sound quality, and enhanced bass response. They come in various configurations, including single-channel (monoblock), two-channel, four-channel, and multi-channel, to power different speaker setups and achieve specific audio goals.