A form of diversity that uses two spaced antennas and two receiver channels tuned to the same frequency. Essentially eliminates signal loss (dropouts) by instantaneously selecting the audio output from the receiver channel having the stronger RF input signal. Also referred to as space diversity or dual-receiver diversity.

Ultra High Frequency. A range of radio frequencies that extends from 300Mhz to 3GHz. Allocated by the FCC for use by satellite systems, broadcasting and a wide range of two-way communication systems that includes wireless microphones.

Universal Serial Bus.

A plug and play interface that is found on both Windows and Apple computers, that allows for connection of various peripherals without rebooting or having to add adapter cards. USB allows for up to 127 devices and supports data speeds of 12 Mbps.

With the advent of 24-bit recording, the issues of how best to lower the resolution of audio to 16-bit for CD manufacture has prompted several responses. UV-22 is a patented process developed by Apogee that is similar to many dithering schemes although they differ in where the added noise is placed.

To convey an electrical signal through wire, two conductors are required. In unbalanced circuits, one conductor carries both signal and supplies ground, unlike in balanced connections. Because of this unbalanced circuits are less expensive to produce, but the down side is the cables are susceptible to noise, especially if lengths of over 30 feet are involved.

In wireless microphones, refers to systems with operating frequencies below approximately 300MHz. In the U.S., most such systems operate somewhere between 170 and 216MHz.

Meter designed to interpret signal levels in a similar way to how human ears perceive loudness, responding more to the average level of sounds rather than to peak levels.

Known in the UK as valves, tubes are devices that amplify electronic signals. With the arrival of the transistor, tubes fell out of popularity except for some very high-end audiophile equipment manufactures, but with the proliferation of digital audio workstations, tubes have seen a reemergence.

An audio processor that extracts the basic component of one audio signal and then superimposes this element onto another signal. To do this, the first audio signal (a vocal for instance) is sent through a series of parallel signal filters that create a signature of the input signal, based on the frequency content and level of the frequency components.

An audio file format created by Microsoft. The standard on Windows machines, the format is used for everything from system and game sounds to CD quality audio. The format has also been accepted as a viable interchange medium for other platforms such as the Mac. The file is identified by the file name extension .wav.