With its two mighty tower speakers, the HT-S8400 stands apart from other home theater package systems. These two-way tall-boys work in concert with the other high-quality speakers to express the full scope and power of your music and other entertainment. No matter whether it's a song, a game, or a movie, the receiver's Dolby Pro Logic IIz decoding creates an enveloping 7.1-channel soundstage with superb ambience. Once you've set the system up and calibrated the speakers - a breeze, thanks to Audyssey 2EQ - you can browse your content seamlessly via the intuitive on-screen menus. The receiver accepts a wide range of playback devices and formats, including PC video via RGB and digital audio from iPod/iPhone via USB. In addition, four HDMI inputs handle 3D video, lossless audio from DTS and Dolby, and video upscaling to 4K via Qdeo technology.