Priced per speaker. The Monitor Audio Radius 180 is rather versatile in the sense that it can be positioned vertically or horizontally. Its versatility means it can be used as a centre channel in a multi-channel music or movie system as well as a main, side or rear speaker. At just 95mm deep, it is ideal for use with a plasma screen or in places where space is at a premium. Comprising of a MMP2 Bass driver and a 1” C-CAM tweeter, the R180 is ideal for small to medium sized rooms, and will perform excellently with other speakers in the Monitor Audio Radius range.