BALANCED
A 2-conductor (plus shield), low-impedance connection. Balanced cables are the preferred method for hum-free interconnection of a given sound system for their noise-rejection characteristics. (Also see Unbalanced.)

CHANNEL
One of any number of signal paths in an audio circuit, such as input channel, output channel, recording channel, left channel, right channel, etc.

DECIBEL (dB)
A term representing the ratio between different audio levels. For example, a ratio of 1000:1 = 60dB.

DELAY
Like an echo, this effect duplicates the original signal, then plays it back at a rate you control. The rate at which these repeats occur is the “delay time.”

EQUALIZATION
Electronic filters that adjust the level of certain frequencies. Used for tone enhancement or to reduce extraneous sounds. Two types of EQ shapes are Peak and Shelving, described below.

IMPEDANCE
Resistance in an electrical circuit measured in Ohms (Ω). Maintaining proper impedance (between amplifier and speakers for example) is important to prevent damage to the amp.

PEAK EQUALIZER CONTROL
Increase or decrease of a frequency range centered at a specific point, resulting in an EQ curve that looks like a hill (increase) or a valley (decrease). (Also see Shelving Equalizer Control.)

SHELVING EQUALIZER CONTROL
Increase or decrease of all frequencies above or below a specific point. (Compare to Peak Equalizer Control.)

TRS (BALANCED)
Acronym for Tip-Ring-Sleeve — the three parts of a two-conductor (plus shield) audio plug. TRS phone plugs are often used for “balanced” connections.

TRS (UNBALANCED RES INSERT)
Another common TRS application is for “dual unbalanced” connections, such as insert send/return jacks or stereo Y-Cord. These are used for inserting an external processor into a signal path.

TS
Acronym for Tip-Sleeve, the two parts of an unbalanced, single-conductor (plus shield) phone plug. TS connectors are sometimes called mono or unbalanced plugs or jacks.

UNBALANCED
A single-conductor (plus shield), high-impedance connection. Most commonly used for instrument connections and cable runs of less than 20 feet.

XLR
The three-pin connector universally used for balanced audio connections. A balanced connection reduces outside noise and interference. (See Balanced above.)