Brooks Cinema ZL 44 Compression Driver

The unit that feeds a sound pressure wave into the throat of a horn (in a horn loudspeaker).

Cut-off Rate (Slope)
The number of dB that a filter reduces the signal for each octave its frequency past the filter's cut-off frequency (outside of the pass band).

Brooks Cinema KP 30 Head
1) In tape recording, the transducer (energy converter) that changes the audio energy from electrical energy to magnetic energy and back; also the devices that apply magnetism to the recording tape for other purposes such as in the erase head.
2) The part of a device that immediately includes the transducer to change sound or audio signals from one energy form to another.

Frequency
The number of cycles of a waveform occurring in a second.

Brooks GT 44 Gain Control
A device that changes the gain of an amplifier or circuit, often a knob that can be turned or a slide that can be moved up arid down.

Amplifier (Power amp, Head)
It's the part of the sound system that actually magnifies or "amplifies" the sound. In other words, it makes stuff louder.

DC
Abbreviation for direct current.

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.