A set of filters that divide the audio signal into 31 different bands allowing for general shaping of the sound.  Each band or filter is centered 1/3 of an octave from its adjacent filters, giving 3 bands per octave.  Most units allow up to 12 dB of boost or cut on each band.

Dating from the 1800s, this connector is one of the best know audio plugs.  Applications are: high impedance microphones, headphones, line level interconnections, speaker level, guitar pickups, and patch bays.  First user was the telephone industry.  Available in 3 conductor, Tip-Ring-Sleeve (TRS, Balanced, Stereo) and 2 conductor, Tip-Sleeve (TS, Unbalanced, Mono).  Similar connector also available in ⅛”.

When speakers are distance from the amplifier or many speakers are to be powered by one amplifier, a 70-volt system is recommended.  It is a high impedance distribution system in which each speaker has a step-down transformer which can be tapped to get different amounts of power form the distributed system.  The amplifier usually has a step-up transformer at it’s output.  Having a high impedance distribution system allows smaller gauge wire to be used and many speakers to be connected to a single power amplifier.  Most background and paging systems are 70-volt.

An electronic device that increases the voltage, current, or power of a signal, by taking energy from a power supply and controlling the output to match the input signal shape, but with larger amplitude.

The “Audio Engineering Society” and the “European Broadcasting Union” professional protocol that conveys two channels of interleaved digital audio data through two-conductor cable.

A special type of transformer with only one winding to produce the voltage.  This is achieved because one part acts as the primary, and the other acts as the secondary, therefore self magnetizing.  The result is a device with higher performance.

Any box like inclosure or surface used to mount a loudspeaker, and which acts as sound absorbers to prevent sound waves from radiating through a designed space.

This is a method of interconnecting audio equipment using balanced lines. This type of connection allows the use of long cable runs while reducing susceptibility to external noise and RFI (Radio Frequency Interference).  Balanced lines use three-conductor connectors, usually XLR or 1/4 TRS Phone.  This allows the use of two audio signals with one 180 degrees out of phase, to cancel out unwanted noise.

This is a single-wire (one conductor) speaker level connection used for joining wires to amplifiers. The plug is typically a four-leafed spring tip that fits snugly into the jack.

An electronic circuit or device that passes frequencies within the middle range and attenuates frequencies outside the range

The range of audio frequencies of a system. The higher the audio bandwidth, the better the sound quality. Expressed in hertz (Hz) or musical octaves.

A protocol for the short-range wireless interconnection technology and data exchange between electronic devices.

A set of electrical conductors common to three or more circuits, which transmit data, audio signals, or power with in a system.

A loudspeaker system in which two or more transducers (speakers) share a common point or axis; typically categorized in two ways: a two-way high-power design for professional audio, or a compact form using two or three speaker drivers, usually in car audio.

A device that changes the overall dynamic range.  A compressor with a ratio of 2:1 would modify a signal so a change in volume of 2 dB (decibels) at the input would only change by 1 dB at the output.  Most compressors have a variable compression range of 2:1 to 20:1 and beyond.

Type of microphone in which a capacitor (condenser) is formed by placing a thin diaphragm in front of a metal disk and applying voltage externally to create sound.  Condenser microphones generally produce a high-quality audio signal and are a popular choice for recording studios.

An electronic filter used in audio applications to split an audio signal into separate frequency bands that can be individually routed to the appropriate drivers capable of producing sound from that frequency on the audio spectrum.

Connecting several devices together in sequence.

Reducing or controlling unwanted motion in the cone or diaphragm of a driver after the signal disappears; the motion can often cause undesired noise or ringing.

The “Digital Audio Workstation” is a computer software system for recording, editing, and producing audio files.

The part of the microphone or speaker that moves and converts sound energy to electrical energy, or vice versa.  It usually has the shape of a cone or dome and is constructed of a thin membrane.

When sound waves change direction or are deflected from their normal path as a result of an encounter with a physical obstacle.

An undesirable change of the original shape of a sound or waveform which will result in an abnormality.

The working part of a speaker that physically creates sound.  The driver typically consists of a voice coil, which is stimulated by a signal from an amplifier and magnet.

An electronic set of filters designed to modify frequency balance of an audio source.

An audio signal processing effect that synthesizes high frequency harmonics.

A device that increases the dynamic range of a signal by decreasing the amount of low-level signals and increasing the amount of high-level signals.

Sound distortion produced by the returning of part of the output signal from a device to the input of the same device.  An in-phase audio loop.

A device that alters a sound by playing two copies of the same signal at the same time, with one significantly slower than the other, and then recombining them.

The number of times a wave repeats per second.  Frequency is measured in hertz (Hz).  For sound, frequency determines pitch.

The sections of frequency between points at the upper and lower ends of the spectrum of radio communication frequencies.  Channels are usually grouped or designated for the same purpose under a frequency.

Related to audio, gain represents the amount of amplification of an audio signal; the increase level of audio or the volume of audio.  Gain is usually expressed in unites of decibels (dB)

Can eliminate unwanted hum and buzz by disconnecting the cable shield connection between the signal ground and the chassis ground.

Unidirectional microphone with a slightly larger rear pickup than the supercardioid microphone, and significantly more rear pickup that a cardioid microphone.

An electronic filter that attenuates frequencies below a cutoff frequency, and passes on frequencies higher than a certain cutoff frequency.

A sound radiator cone mounted onto a loudspeaker, or part of a custom exploded speaker cluster, to increase the overall efficiency of the driving element(s); emits midrange and higher range frequencies (500-20,000 Hz).

An expression of the resistance and reaction of an electronic component in an alternating-cuttent (AC) circuits; measured in ohms.

A type of small microphone that becomes hands-free by being fastened to clothing such as collars and ties; sometimes referred to as a lapel microphone.

A device designed to leave the dynamic range of the signal unmodified until it reaches a certain threshold above which the signal is compressed at a high ratio (16:1 or greater) so it does not get louder.

This is the specified strength of an audio signal used to transmit analog sound between audio components such as CD and DVD players, mixing consoled and equipment.  Consumer audio is at -10 dBV, while pro-audio is at +4 to +10 dBu.

An electronic filter that attenuates frequencies above a cutoff frequency, and passes on frequencies lower than a certain cutoff frequency.

This is the signal strength of the output of a microphone, -40dBV.

A device for combining or multiplying signal inputs together into a common output.

An electronic device or software that regulates the volume of an audio signal.  Noise gates attenuate signals registering below the cutoff decibel, by a fixed ratio.

The change of tone quality for audio sources received received off-center (off-access) to the microphone.