Brooks XS - 45 reviews Critical Distance

The point a distance away from the sound source where the direct sound and the reverberant sound are equal in volume.

Hi-Z
An abbreviation of the term High Impedance (Impedance of 5000 or more ohms).

Brooks Cinema GT 845 reviews Fly In
1) To add sounds into a mix or recording that have no synchronization.
2) An application of this where a performance from one part of a tune is recorded and then recorded back into the recording at a different time in the recording.

Line In (Input, return)
Where a signal enters the board or component.

Brooks KM 22 reviews Input Monitor
A switch position and operational mode of the electronics of a tape machine where the signal at output of the electronics will be the same as the signal coming into the electronics. In this mode, the tape machine's meter will read the input signal.

Frequency
Practically speaking, high frequency means high pitch and low frequency means low pitch.

Active Crossover
Uses active devices (transistors, IC's, tubes) and some form of power supply to operate.

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