There are three 3.25" main speakers, one 4" subwoofer and a 4" passive radiator as well as a bi-amplified 60 watt amplifer all contained within this highly efficient ENERGY STAR qualified device. There is also an output for optional external subwoofer. The speakers use ferrofluid and neodymium magnets for improved sound quality and dispersion, and the cabinet is made of MDF (medium density fiberboard), the same material uses in most high-end loudspeakers. The PhaseCue system creates a virtual surround system making it sound like there are speakers 8 feet apart, and even behind you. Although it is not a complete replacement for a full 5.1 surround system, it is much more affordable, compact and simple to setup. Designed to be as easy to set up and use as possible, the ZVOX 415 will automatically turn on after the audio source is powered up, and return to idle mode once the source has been turned off. If the TV being used has a "variable" output audio jacks, the TV remote can be used to control the TV/415 volume. However, the device can also be controlled using the supplied remote control, which also controls PhaseCue (virtual sound), subwoofer level and treble. There are two "mixing" RCA input jacks in the rear which will automatically mix the two signals, if both inputs are used. A 2-meter RCA/RCA cord is included.