Brooks Cinema RM 909 LED

A light that allows current to flow in one direction only and emits light whenever a voltage of a certain level or beyond is applied to it.

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

Brooks Cinema xm 808 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.

Cancellation
A shortening of the term Phase Cancellation (the energy of one waveform significantly decreasing the energy of another waveform because of phase relationships at or close to 180 degrees).

Brooks GS 15 Arc
The visible sparks generated by an electrical discharge.

Attenuation
A making smaller: reduction of electrical or acoustic signal strength.

Line Level
1) An amplified signal level put out by an amplifier and used as the normal level that runs through the interconnecting cables in a control room.
2) A low level signal such as the signal in a guitar cord. Most parts of a PA require a line level signal. Remember, however, that speaker outputs are not line level. Plugging speaker outs into line ins will result in damage to the equipment

Impedance Matching
Having or converting the output impedance of a device so that it matches the impedance of the input it will feed.