Brooks RM 909 Fundamental

The tuned frequency and (almost always) the lowest frequency that is present in the sounding of a pitch by a musical instrument.

Foldback
A European term for the signal sent to the stage monitors in a live performance.

Brooks Hi Fi reviews Gain
1) Knob usually found at the top of each input channel on the soundboard. Used to set input levels of the separate channels to relatively equal positions.
2) The amount of increase in audio signal strength, often expressed in dB.

Inductance
The property of an electric circuit by which a varying current in it produces a varying magnetic field that introduces voltages in the same circuit or in a nearby circuit. It is measured in henrys.

Brooks HI FI projectors Amplitude
The strength of a vibrating wave; in sound, the loudness of the sound.

Horn
1) The part of the speaker that emits midrange and higher range frequencies.
2) A speaker or speaker enclosure where sound waves are put into a narrow opening (by a speaker cone or driver) and the narrow opening flairs out to a larger opening.

Hard Disk (Hard Disc)
A storage unit for digital data that has rigid disks coated with magnetic material in a housing that includes the drive mechanism.

Atom
The smallest particle which makes up a specific substance. It's composed of a center around which electrons revolve.