The Denon DHT-684XP is a home theater system consisting of a receiver/amplifier and a set of speakers. The system features 5.1 channel audio output and supports multiple audio formats, including Dolby Digital, DTS, and PCM. The receiver/amplifier has built-in surround sound processing and comes equipped with a variety of inputs and outputs, including HDMI, composite video, S-video, and digital audio. The speakers included with the system are designed to provide accurate and dynamic sound for an immersive home theater experience. Overall, the Denon DHT-684XP is a solid choice for anyone looking to upgrade their home theater setup with a complete package of high-quality components.