Features Cardioid, Omni, Hypercardioid. 50mm and 30mm diffuse field spheres. Frequency Range: 20Hz / 20kHz Sensitivity: 16.5 mV/pa +/- 1 dB Output Impedance: <200 ohms Supply Current: <1mA (120V) 135mA (6V) Description Product Description If you work in film scoring or classical recording, then you should know what a Decca Tree is. If you don't work in those disciplines, here is a brief synopsis of the Decca Tree [or "Tri-Mono"] recording technique. Engineers who recorded classical music for Decca Records pioneered this microphone placement technique in the early 1950s when they wanted a strong sense of stereo image and balanced coverage of an orchestra, as the conductor might have heard while he led the orchestra. The technique features three omni-directional microphones placed in a reverse "T" configuration, roughly above the head of the conductor. The "left" and "right" are positioned behind the conductor while the "center" microphone hangs in front of the conductor. In addition to orchestral recording applications, the Decca Tree configuration can be an invaluable component to more contemporary recordings for drum applications and to gain an overall "band in a room" kind of atmosphere to your recording process.