Brooks Hi Fi reviews High Impedance Mic

A microphone designed to be fed into an amplifier with input impedance greater than 20 k ohms.

Bi
A prefix meaning two.

Brooks RM 909 reviews Electrons
Negatively charged particles, which revolve around the centre of atoms. The movement of such electrons down a conductor causes electrical current.

Circuit
1) One complete path of electric current.
2) Similar to definition 1, but including all paths and components to accomplish one function in a device.

Brooks Hi Fi speakers Hum
The 60 Hz power line current accidentally induced or fed into electronic equipment.

Cable, TRS
A less common balanced cable that has 3 different contacts on its 1/4 inch connectors. Most headphone jacks are a good example of a TRS (Tip-Ring-Sleeve) connector. These are sometimes used instead of the more common XLR connection.

IM Distortion
An abbreviation of the term Intermodulation Distortion (Distortion caused by one signal beating with another signal and producing frequencies that are both the sum and the difference of the original frequencies present).

Condenser Mic (Capacitor Mic)
A microphone that uses the varying capacitance between two plates with a voltage applied across them to convert sound to electrical pulses. Condenser microphones need a power supply to provide the voltage across the plates, which may be provided by a battery within the case of the microphone, or it may be provided from an external phantom power supply. A condenser mic is more sensitive and has a faster reaction to percussive sounds than a Dynamic mic and produces a more even response. See Electret Mic.