AV Glossary

The terms that show up in AV proposals and on this site, in plain English. If one is missing, ask us.

A

AV-over-IP: Sending audio and video across a standard IP network, on the same kind of switches and cabling that carry a building's other data, instead of on dedicated AV cable. Because the AV now shares the network, whether it works depends on how that network is segmented and managed.

DvLED (Direct View LED): A display where the LEDs themselves make the picture, instead of lighting an LCD panel from behind. LED walls are direct view LED.

IMAG (Image Magnification): Live camera shots of the person on stage, shown on large screens so the back of a big room sees a face rather than a figure.
ITSM (IT Service Management): The system an IT team uses to log, route and track incidents and requests as tickets. When AV faults arrive there, your team handles them like any other IT issue instead of fielding a phone call.

LED Wall: A large display built from LED panels tiled edge to edge into one video surface, with no bezel lines between panels. You will see them behind stages, in lobbies and on broadcast sets.
Line Array: A loudspeaker system built from several speaker elements stacked in a vertical column, usually flown (hung) above the audience. The shape keeps the sound level more even from the front rows to the back of a large room.

Multicast: A way of sending one stream to many receivers at once, with the network copying it only to the devices that asked for it. Unmanaged, multicast floods every port it can reach, which is why a network has to be set up for AV before AV goes on it.

Projection Mapping: Projecting video onto shaped surfaces, such as set pieces, walls or the front of a building, instead of onto a flat screen. Software warps and blends the image so it fits the surface it lands on.

Q-SYS: A software-based platform that runs a room's audio, video and control as one system on the network, instead of as separate boxes wired together. We standardize on Q-SYS, so a huddle room and a boardroom behave, report and get supported the same way.
QoS (Quality of Service): Rules on a network that decide which traffic goes first when the network is busy. For AV, QoS keeps audio and video from stalling behind a large file transfer.

Rigging: Hanging equipment such as speakers, lights, LED panels and scenery from a building's overhead structure, using truss, chain motors and steel cable. On our shows, rigging calls belong to the Technical Director and are not subject to schedule or budget override.
RMA (Return Merchandise Authorization): A manufacturer's approval to send back a faulty part for repair or replacement, usually under warranty.
RTMP (Real-Time Messaging Protocol): A protocol for sending a live video stream from an encoder to a streaming platform. Many streaming platforms take a live feed this way.

SDVoE (Software Defined Video over Ethernet): A way of sending high-quality video across a 10 gigabit Ethernet network with very little delay, with switching and routing handled in software. The SDVoE Alliance, an industry group, backs it.
Streaming: Encoding live or recorded audio and video and sending it over the internet to people who are not in the room. For a live event that usually means switching between cameras, adding graphics and sending one feed to each platform the audience watches on.

VLAN (Virtual Local Area Network): A separate network segment created in software on shared switches, so one kind of traffic stays apart from the rest without its own cabling. Putting AV on its own VLAN keeps it apart from systems such as point of sale or guest wifi.