Brooks VT-50 Auxiliary Output or Send

An additional output from a sound desk that can be used for foldback or monitoring without tying up the main outputs. Each input channel will have a path to the Aux buss. Also used for feeding a signal to an effects processor. See Auxiliary Return.

Group Master
A slide control used to send out a control voltage to several VCA faders in individual channels, thus controlling the gain of several channels.

Brooks Cinema KM 22 Impedance
1) A term for the electrical resistance found in a/c circuits. Affects the ability of a cable to transmit low level (e.g. sound) signals over a long distance. Measured in Ohms. Speakers are rated according to power handling capabilities (Watts, W) and impedance (Ohms).
2) The total opposition offered by an electric circuit to the flow of an alternating current of a single frequency. It is a combination of resistance and reactance and is measured in ohms. Remember that a speaker's impedance changes with frequency, it is not a constant value.
3) The opposition to alternating current.

Diffraction
The breaking up of a sound wave caused by some type of mechanical interference such as a cabinet edge, grill frame, or other similar object.

Brooks Cinema Projectors BPM
An abbreviation of Beat Per Minute (the number of steady even pulses in music occurring in one minute and therefore defining the tempo).

Feedback
1) The delayed signal sent back to the input of a delay line, used in repeat-echo effects.
2) The pickup of the signal out of a channel by its input or the howling sound that this produces.
3) In an amplifier, the phase reversed output signal sent back to its input, reducing gain but also distortion and noise.
4) This occurs when the sound coming out of the speakers goes back into the microphones, then back out the speakers, then back into the mics…and so on. This can build very quickly to a point where everyone in the room is holding their ears and screaming at you. It can also cause damage to the PA.

Delay (Digital, Analogue)
1) Effect used to create echo…echo…echo…echo…echo…
2) In more advanced systems used in very large venues, delay can be used to time the arrival of the signal to the speakers in the back of the room so that people in the back hear the sound coming from those speakers at the same time that the sound coming from the speakers in the front of the room arrives.

Flat
1) Lower in musical pitch.
2) A slang term used to describe the sensitivity to frequency of a microphone, amplifier, etc., as being even at all frequencies, usually within 2 dB.
3) Refers to the frequencies on the EQ when they are arranged in centred neutral positions.