The Philips HTS6515D/37 is a DVD home theater system that uses simulated surround sound to provide modern home theater technology without the clutter. Using what Philips calls "Ambisound" technology, the distinguishing feature of this package is that it splits 5.1 surround into just two speakers, which then use "the combined effect of psychoacoustic phenomena, array processing and precisely angled driver positioning" to deliver a simulation of a proper surround system. The HTS6515D/37 is also noteworthy for offering compatibility with portable devices through an MP3 player input that connects to your MP3 player's headphone jack, an Ipod dock, and a USB input for flashdrives and other portable media. The system is basically the same as the 6600 model but drops the AM tuner in favor of FM only, but also features 1080p support in its upscaling HDMI DVD player. It also features DTS sound in addition to Dolby Digital.