70V / 100V — Constant-Voltage Distributed Audio
70V (and 100V) distributed audio systems allow a single amplifier to drive many speakers over long cable runs without impedance-matching calculations, using transformer-coupled taps at each speaker.
AEC — Acoustic Echo Cancellation
DSP algorithm that removes room reflections and far-end voice echo from microphone signals to enable full-duplex conferencing.
AES — Audio Engineering Society and Digital Audio Standards
The Audio Engineering Society (AES) and its key standards — AES3, AES67, MADI, and OCA — that define professional digital audio.
AES67 — Audio over IP Interoperability Standard
AES67 is the SMPTE/AES standard for interoperable audio over IP, defining RTP transport, PTP clocking, and SDP/SAP discovery so that Dante, Ravenna, Livewire, and Q-LAN devices can exchange audio across platforms.
ARC and eARC — Audio Return Channel
ARC and eARC carry audio from a display back to an audio device over the HDMI cable — eliminating a separate audio cable from the display to the DSP or amplifier.
Beamforming — Steered Microphone Arrays
Beamforming uses an array of microphone capsules with DSP spatial filtering to steer a directional pickup pattern toward active speakers, rejecting off-axis noise — the technology behind MXA, Parlé, TeamConnect, and Stem ceiling microphones.
BYOD — Bring Your Own Device
Supporting personal laptops, tablets, and phones to connect to room AV systems for presentation and conferencing without fixed infrastructure endpoints.
BYOM — Bring Your Own Meeting
BYOM allows a room's AV infrastructure (camera, microphone, speakers, display) to be used by a video conference running on the user's personal laptop, bridging the gap between dedicated room codecs and unmanaged BYOD rooms.
Chroma Subsampling — 4:4:4, 4:2:2, and 4:2:0
Chroma subsampling reduces video bandwidth by transmitting less color (chroma) information than luminance — understanding 4:4:4 vs. 4:2:0 determines whether a signal chain can carry 4K60 over HDMI 2.0.
CMRR — Common Mode Rejection Ratio
CMRR quantifies how well a balanced audio input rejects noise and interference that appears equally on both conductors — the key specification that makes balanced audio essential for long cable runs in AV systems.
Codec — Compression/Decompression
A codec encodes and decodes audio or video signals using compression algorithms — understanding codecs determines the quality, latency, and bandwidth trade-offs in video conferencing, AV-over-IP, and streaming systems.
Dante — Digital Audio Network Transport
Industry-standard audio networking protocol by Audinate carrying uncompressed multi-channel digital audio over standard Gigabit Ethernet with sub-millisecond latency.
dB — Decibel Reference Suffixes (dBu, dBFS, dBSPL, dBm, dBV)
Decibel suffixes define the reference point for audio level measurements — confusing dBu with dBFS or dBSPL is one of the most common errors in gain structure setup.
DSP — Digital Signal Processing
Real-time digital manipulation of audio signals using algorithms running on dedicated processor hardware, enabling mixing, routing, EQ, dynamics, and conferencing functions in AV systems.
EDID — Extended Display Identification Data
EDID is the data structure a display presents to a source to advertise its supported resolutions, refresh rates, and audio formats — the root cause of most HDMI "no signal" and wrong-resolution failures.
Gain Structure — Setting Levels Through the Signal Chain
Gain structure is the systematic setting of amplification and attenuation at every stage in an audio signal chain to maximize signal-to-noise ratio while maintaining adequate headroom before clipping.
HDBaseT — HDMI over Category Cable
HDBaseT transmits 4K HDMI, RS-232, IR, Ethernet, and PoE over a single Cat6A cable up to 100 m — the dominant long-distance HDMI extension standard in installed AV.
HDCP — High-bandwidth Digital Content Protection
HDCP is the content protection handshake required on every HDMI link carrying protected content — a single non-compliant device in the chain blocks the signal entirely.
HDR — High Dynamic Range
HDR extends the brightness and color range of video signals beyond standard dynamic range, enabling displays to show specular highlights and deep shadows simultaneously — relevant for 4K content delivery and display specification in AV.
IGMP — Internet Group Management Protocol
IGMP controls multicast group membership on Ethernet networks — required for Dante audio and AV-over-IP video to work correctly without flooding every switch port with unwanted traffic.
Impedance — Audio and Video Impedance Matching
Impedance determines how audio and video signals are loaded and transferred between devices — mismatched impedance causes signal loss, frequency response errors, and reflections in video systems.
Latency and Jitter — AV Network Timing
Latency is the delay from source to destination; jitter is the variation in that delay — both critically affect live audio, video conferencing, and AV-over-IP systems.
LPCM — Linear Pulse Code Modulation and Audio Formats
LPCM is the uncompressed digital audio standard carried over HDMI and AES3 — understanding LPCM vs. compressed formats (Dolby Digital, DTS, Atmos) determines what a system can de-embed, process, and distribute.
MTR — Meeting Transformation Room
Premium hybrid collaboration spaces with certified hardware, AI-driven audio/video, and deep UCC platform integration for Teams, Zoom, and Webex.
NDI — Network Device Interface
IP video protocol by NewTek/Vizrt streaming broadcast-quality video over standard Ethernet with automatic device discovery, widely used in production, streaming, and corporate AV.
PoE — Power over Ethernet
PoE delivers DC power over Cat cable alongside network data, eliminating separate power supplies for IP cameras, VoIP phones, wireless APs, HDBaseT receivers, and AV control devices.
PTP — Precision Time Protocol (IEEE 1588)
PTP (IEEE 1588) synchronizes clocks across a network to sub-microsecond accuracy — essential for Dante, AES67, AV-over-IP, and any system where audio or video devices must share a common time reference.
PTZ — Pan/Tilt/Zoom Camera
Motorized camera with independent pan, tilt, and optical zoom motors for remote framing control in conference rooms, lecture halls, and broadcast studios.
QoS — Quality of Service
QoS prioritizes time-sensitive AV traffic (Dante audio, AV-over-IP) over bulk data on shared networks, preventing dropouts caused by congestion from IT traffic.
RS-232 — Serial Control Interface
RS-232 is the most common wired control interface in AV — used to control displays, projectors, PTZ cameras, and DSPs from control processors via simple ASCII or binary command strings.
RT60 — Reverberation Time
RT60 is the time in seconds for a sound to decay 60 dB after the source stops — the primary acoustic measurement that determines whether a room is suited for speech, music, or neither.
RTP and RTSP — Real-Time Transport Protocols
RTP carries real-time audio and video over IP networks; RTSP controls the playback of those streams — together they underpin Dante, AES67, IP camera streaming, and IPTV in AV systems.
SDI — Serial Digital Interface
SDI is the professional broadcast video standard for lossless uncompressed video over coaxial cable — immune to HDCP, capable of very long runs, and the backbone of broadcast and live production AV systems.
SIP — Session Initiation Protocol
SIP is the signaling protocol for VoIP and video conferencing — understanding SIP is essential for integrating telephone interfaces, paging systems, and SIP-based video conferencing endpoints with AV systems.
SNR — Signal-to-Noise Ratio
SNR quantifies how much stronger the desired signal is than the noise floor — a fundamental specification for microphones, preamps, DSPs, and amplifiers that determines how quiet a system can be before background noise becomes audible.
STI — Speech Transmission Index
STI is the standard objective measure of speech intelligibility in a room — a value from 0 to 1 that predicts how clearly spoken words will be understood by listeners, accounting for reverberation, noise, and system distortion.
THD — Total Harmonic Distortion
THD measures the nonlinear distortion added by audio equipment — amplifiers, DSPs, and converters — expressed as a percentage or dB below the fundamental, indicating how cleanly the device reproduces a signal.
UCC — Unified Communications and Collaboration
Integrated platforms combining video conferencing, voice, messaging, and content sharing for seamless hybrid communication — Teams, Zoom, Webex, and Google Meet.
VISCA — Video System Control Architecture
VISCA is the dominant PTZ camera control protocol — a binary command set sent over RS-232 or UDP/TCP that commands pan, tilt, zoom, focus, iris, and preset recall on virtually every professional PTZ camera.
VLAN — Virtual Local Area Network
VLANs segment a physical network into isolated Layer 2 broadcast domains — essential for separating AV, IT, and control traffic while sharing common switch infrastructure.