On the audio side, a Dolby Digital 5.1 decoder allows the NS400D to take advantage of the latest Surround Sound technology. Adjustable channel controls allow you actually to optimize the sound reproduction in your specific listening environment. On the video end of things, the 400d packs in a plethora of features, including an impressive new digital technology that both sharpens the image and keeps it looking natural. On-screen menus allow you to control everything with ease from the multi-feature remote. An enhanced Bookmark feature makes it easy to set placeholders for up to 50 DVDs. Sony's Precision Drive 2 and Dynamic Tilt Compensation allow for better tracking of imperfect disks. A variety of outputs, including S-Video, Optical digital, Coax digital, Dolby 5.1 and analog stereo top off this feature-packed DVD from Sony.