An ultrasonic signal used in analogue recording to improve the linearity of the magnetic recording process and thus ensure the accuracy of the recorded audio signal. The bias freqeuency is typically between 80kHz and 150kHz. It is also used drive the erase head. Bias is generated by a bias oscillator.

Software which is not fully tested and may include bugs.

Also known as TT or Tiny Telephone Plugs. A miniaturised form of the PO316 professional jack plug derived from the telecommunications industry and widely used for balanced connections on professional high-density patch bays. (cf. B-Type Plug)

A special type of acoustic absorber which is optimised to absorb low frequency sound waves.

see Proximity Effect.

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.