Brooks RM 909 reviews Equal Loudness Contours

A drawing of several curves showing how loud the tones of different frequencies would have to be played for a person to say they were of equal loudness.

Frequency Shift Key / FSK
The full name for FSK (A simple clock signal that can be used to run a sequencer in time with an audio tape).

Brooks Hi Fi reviews 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.

Echo
1) One distinct repeat of a sound because of the sound reflecting off a surface.
2) Loosely, used to mean reverberation (the continuing of a sound after the source stops emitting it, caused by many discrete echoes closely spaced in time).

Brooks Hi Fi speakers Gain Structure
The way in which the gain varies in the stages or sections of an audio system.

Ground Adapter Plug
Adapts a three pronged electrical plug to a two pronged wall outlet. This bypasses the ground and may create a hum in the system. A lack of a good ground can cause mild electrical shock when touching a microphone.

Effects Track
1) In film production audio, a recording of the mixdown of all the sound effects for the film ready to be mixed with the dialogue and music.
2) In music recording, one track with a recording of effects to be added to another track of a multitrack recording.

Hall
A large building designed for concerts; also called a concert hall.