An 8-channel amplifier is an audio amplifier that has eight separate channels of amplification. Each channel can power a different speaker or set of speakers in a multi-speaker audio system. The most common configuration for an 8-channel amplifier is to have seven channels for the front and rear left and right speakers, and an eighth channel dedicated to powering a subwoofer. This is commonly referred to as an "8.1" or "8.1 surround" system.

An 8-channel amplifier can be used in a variety of audio systems, such as home theater systems, professional audio setups, or commercial installations. In a home theater system, the amplifier would be used to power a set of surround sound speakers and a subwoofer, while in a professional audio setup or commercial installation, the amplifier would be used to power multiple speakers in a large room or venue.

The power output of an 8-channel amplifier can vary, depending on the specific model and manufacturer. However, most 8-channel amplifiers will provide enough power to drive most speakers and subwoofers in a typical home theater or professional audio system. It is important to match the power output of the amplifier to the speakers and subwoofers being used to ensure optimal performance and avoid damage to the equipment.