The frequency response of a loudspeaker system at the lower end of the spectrum. The physical size and design of a loudspeaker cabinet and the bass driver (woofer) determine the low frequency extension (the lowest frequency the speaker can reproduce at normal level) and the how quickly the signal level falls below that frequency.

A specific configuration of sounds or other parameters stored in memory and accessed manually or via MIDI commands.

The range of frequencies passed by an electronic circuit such as an amplifier, mixer or filter. The frequency range is usually measured at the points where the level drops by 3dB relative to the maximum. (See also Q)

A filter that removes or attenuates frequencies both above and below the centre frequency at which it is set, and only passes a specific range — or band — of frequencies. Band-pass filters are often used in synthesizers as tone shaping elements.

Where protection from electromagnetic interference and freedom from earth references are required, a balanced interface is used. The term ‘balanced’ refers to identical (balanced) impedances to ground from each of two signal carrying conductors which are enclosed within an all-embracing overall electrostatic screen. This screen is grounded (to catch and remove unwanted RFI), but plays no part in passing the audio signal or providing its voltage reference. Instead, the two signal wires provide the reference for each other — the signal is conveyed ‘differentially’ and the receiver detects the voltage difference between the two signal wires. Any interference instils the same voltage on each wire (called a common mode signal) because the impedance to ground is identical for each wire. As there is therefore no voltage difference between the two signal wires, any interference is therefore ignored (rejected) completely by the receiver.

This word has several meanings in recording. It may refer to the relative levels of the left and right channels of a stereo recording (eg. Balance Control), or it may be used to describe the relative levels of the various instruments and voices within a mix (ie. Mix balance).

The alignment of a tape head which references the head gap to the true vertical relative to the tape path. (cf. 'Wrap' and 'Zenith').

Dedicated mixer inputs used to receive external effects into the mix. Aux return channels usually have fewer facilities than normal mixer inputs, such as no EQ and access to fewer auxiliary sends. (cf. Effects Return)

A separate independent output signal derived from one or more input channels on a mixing console, usually with the option to select a pre- or post-fader source and to adjust the contribution level. Auxiliary sends from all channels are bused together before being made available to feed an internal signal processor or external physical output via the corresponding Aux Master level control. Sometimes also called Effects ('FX'), Cue or Artist sends.

A common facility on tape machines or other recording devices that enables specific time points to be stored and recalled. For example, you may store the start of a verse as a locate point ('marker') so that you can get the tape machine or DAW to automatically relocate the start of the verse after you've recorded an overdub.