Glossary

A (ampere)
SI unit of electric current.

ASP (Analogue Signal Processing)
Audient terminology used for analogue signal-processing products/technology.

CPU (Central Processing Unit)
The main processor in a computer.

DC (Direct Current)
Electrical current flowing in one direction.

DoC (Declaration of Conformity)
A manufacturer's formal compliance declaration.

DSP (Digital Signal Processing)
Digital processing used for functions such as iD24's low-latency monitor mixer.

EQ (Equaliser)
A processor used to alter the frequency balance of audio.

FAQ (Frequently Asked Questions)
A collection of common questions and answers.

FCC (Federal Communications Commission)
United States communications regulator referenced in the compliance declaration.

GB (gigabyte)
A unit commonly used to describe computer memory/storage capacity.

GUI (Graphical User Interface)
The visual controls of an application such as the iD Software Mixer.

HV (High Voltage)
A general abbreviation for high voltage.

JFET (Junction Field-Effect Transistor)
The transistor technology used in iD24's discrete instrument input stage.

LED (Light-Emitting Diode)
A light indicator, such as iD24's meters and status indicator.

RAM (Random Access Memory)
Working memory used by a computer while applications are running.

RoHS (Restriction of Hazardous Substances)
Regulatory requirements restricting specified hazardous substances in electrical/electronic equipment.

THD+N (Total Harmonic Distortion + Noise)
A measurement combining harmonic distortion and noise relative to the test signal.

USB (Universal Serial Bus)
The computer connection used by iD24 for audio, control and power.

V (volt)
SI unit of electrical potential difference.

ADAT (Alesis Digital Audio Tape)
An optical multichannel digital-audio format. iD24 carries eight channels at 44.1/48 kHz and four channels using SMUX at 88.2/96 kHz.

ADC (Analogue-to-Digital Converter)
Converts analogue audio into digital audio for the computer/digital system.

ASIO
A low-latency Windows audio-driver protocol used by professional audio applications.

Balanced connection
A connection using hot, cold and shield conductors to improve rejection of common-mode interference. iD24's balanced line connections use TRS or XLR as appropriate.

Clock / word clock
The timing reference that keeps digital audio devices sampling in synchronisation. iD24 has an internal clock, can lock from optical input, and provides a BNC word-clock output.

Cue mix
An independent artist/headphone monitor mix, typically used for a performer feed or as a selectable loopback source.

DAC (Digital-to-Analogue Converter)
Converts digital audio into analogue audio for speakers/headphones.

DAW
Digital Audio Workstation - recording, editing and mixing software such as Pro Tools, Logic Pro, Cubase/Nuendo or Ableton Live.

dB (decibel)
A logarithmic unit used to express ratios such as signal level, gain or attenuation.

DAW THRU
A routing mode that sends a DAW playback pair directly to an output. On iD24 this bypasses the normal monitor-volume control for line outputs and can be full scale; the headphone level control remains active for the headphone path.

dBFS
Decibels relative to digital full scale. 0 dBFS is the maximum digital level.

dBu
An analogue voltage-level reference where 0 dBu corresponds to 0.775 Vrms.

DI / instrument input
A high-impedance input intended for instruments such as electric guitar or bass. iD24 uses a discrete JFET input on the front panel.

HPF (High-Pass Filter)
A filter that reduces frequencies below its cutoff. iD24's hardware HPF is 100 Hz.

I/O
Input/output.

Insert
A send/return point in an audio path used to patch an external processor. iD24's analogue inserts sit before the ADC and are half-normalled.

Loopback
A routing function that sends selected computer/mixer audio back into the host as a recordable stereo input. iD24 loopback is on USB inputs 11+12.

Pad
An attenuator used to reduce signal level before amplification. iD24 provides a -10 dB pad on each analogue input.

Phantom power / 48V
DC power supplied through an XLR microphone connection for compatible condenser microphones/active devices.

Polarity invert
Reverses the polarity of an audio signal. It is commonly used when checking relationships between multiple microphones or sources.

S/PDIF (Sony/Philips Digital Interface Format)
A two-channel digital audio format. iD24 can use optical S/PDIF at sample rates up to 96 kHz.

SMUX
A method of carrying higher-sample-rate ADAT audio by using more of the optical data capacity per audio channel. iD24 carries four ADAT channels at 88.2/96 kHz.

TRS
Tip-ring-sleeve connector. Depending on the application it can carry a balanced mono signal or an unbalanced stereo signal; the connector itself does not guarantee one format.

TS
Tip-sleeve connector, used for the unbalanced iD24 instrument input.

XLR
A locking multipin connector commonly used for balanced microphone/line audio. iD24's microphone inputs use 3-pin XLR connections.