AV Glossary: The Terms For Planners

For rookies and experienced planners alike, AV terminology can feel like a foreign language. For those in the industry, a lot of times we don’t think twice about throwing around acronyms and slang. Why would we? After all, it’s our “native tongue”. Unfortunately this contributes to many planners’ fears that they’re somehow being taken advantage of, or at the very least, unsure exactly what they’re paying for when the AV bill comes due. Now’s your chance to get the inside track and learn a little “conversational AV”. So sit back, relax, and let us be your guide!


To help keep things straight, we’ve split things up into a few different categories:

  • Audio Terminology
  • Video/Display Terminology
  • Other Equipment
  • Production Terminology and Slang



Audio Terminology


Center Fill

A low-profile speaker placed downstage and facing the audience. It’s used to “fill” the center audience with sound, and shouldn’t be confused with a Foldback (see below).



Sometimes incorrectly used to refer to a Confidence Monitor or DSM, a foldback is an audio speaker placed downstage, facing the presenter/entertainment. This allows the presenter to hear audience questions being asked on a microphone, or a performer to hear themselves on stage.


Lav Mic – Lavalier Microphone

A small microphone that clips onto a lapel, shirt, or suit jacket.


Line Array

A type of audio speaker where the speaker cabinets are smaller and stacked on top of one another, with each cabinet pointed at, and responsible for covering, a portion of the audience. Aiming them in this manner often causes the stack to be curved, as the lower cabinets point to the front of the audience and the higher ones point to the back. These are commonly seen in concerts and other large venues, but are being used more frequently in events of all types.


Monitors (Audio)

Audio monitors are on-stage speakers, frequently pointed back at the presenters or performers so they can hear themselves, audience members, or other audio (see also: Foldback).


Ringing Out the Room

The process of determining the natural “sound” of the room, specifically which frequencies are most likely to cause feedback. By listening carefully to the sound of the room (that’s what the sound person’s doing when they are saying, “Two hey.. Hey hey… one two… hey HEY…” for what seems like an eternity), they can use an equalizer to reduce those specific frequencies in the audio setup. This reduces the likelihood of painful feedback from microphones.


Video/Display Terminology:


Aspect Ratio

When talking about video or projection screens, the aspect ratio is the ratio of the width to the height of a video screen. This should not be confused with the actual dimensions of the screen, but refers more to the “shape” of the screen. The most popular aspect ratio for modern displays is 16:9, also known as “widescreen”. The older, more “squarish” screens most often have an aspect ratio of 4:3, and are known as “traditional” or “full-screen” displays. For bonus points, you should say “Sixteen TO Nine” instead of “Sixteen BY Nine”, but the latter is just fine in most circles.


Confidence Monitor

A type of downstage video monitor (see also: DSM). A confidence monitor doubles what’s being displayed to the audience on the main projection screens or displays, so named because it gives the presenter the “confidence” not to turn around and look at the screens to make sure they’re on the correct slide. Depending on the size of the stage there can be more than one, and it should not be confused with a teleprompter. It does not show notes or scripting, just what’s on the main screens.


DA Distribution Amplifier

A device that splits and amplifies video signals. This allows video from a single source to be displayed on multiple screens. Keep in mind it’s not a switcher, just a way of splitting the signal.



AV slang for downstage monitors (see below), but most often used when the DSMs are covered or hidden from the audience via a little “house” made of fabric or hard panels.


Double-Stacked Projectors – AKA “Running Spares”

When two video projectors are focused onto a single screen, displaying the same image, and mounted directly on top of each other. Doing so combines the brightness of the two projectors, making a brighter image and serving as a backup in case one of the projectors goes down. The resulting brightness is not twice as bright, but closer to 1.5x as bright. The second projector serves as backup for the other. The projectors are most commonly “stacked” on top of each other.


Downstage Monitor (DSM)

A monitor placed downstage (either on it or just below in front of it) that can be seen by the presenter, but not the audience. DSMs can display presentation notes, scripting, or what’s being displayed on the audience monitors (see also: Confidence Monitor).


Four K/4K

A widescreen video display resolution roughly four times the resolution of HD. There’s a lot more to it than that, but that’s the easy way to remember it. Depending on the equipment, that’s usually a horizontal resolution of 3840 or 4,096 pixels.


High Definition/HD

A widescreen, 16:9 video display resolution of either 1280×720 or 1920×1080 pixels.


IMAG – Image Magnification

The display of live camera video on projection screens or other displays of the action taking place on a stage, allowing a large audience to see what’s going on more clearly.



The measure of brightness for projectors and lights. Projectors are often referred to by their ANSI (American National Standards Institute) rating, with a “2k projector” being rated at 2,000 ANSI lumens, a “4k projector” being 4,000, a “10k projector” at 10,000, and so forth. Not to be confused with a “4k display” which refers to the resolution of the display (see above), not the brightness.


Monitors (Video)

Video monitors (besides confidence monitors) are displays designed specifically for reference by technicians, crew, or performers.


PIP –  Picture in Picture

The ability to layer video or presentation materials. Most often seen in the context of panoramic (or ultra-wide) screens, where the IMAG is being layered over branded imagery or presentations, rather than filling the entire screen.


Presidential Teleprompter

A specific type of teleprompter commonly used by politicians and other celebrities at major speeches. The script is reflected onto plates of glass in front of the presenter, so they can appear to be looking directly at the audience. See also: Teleprompter.


Running Spares

Running two or more projectors simultaneously, showing the same image, in the same location, at the same time. If one of the projectors fails, the image is still visible due to the other(s) still projecting, just at a lower brightness. See also: Double Stacked Projectors.


Shadow Boxes

A covered or shielded confidence monitor in the form of a little “house” made of fabric or hard panels. See also: Doghouse, Confidence Monitor, Downstage Monitor (DSM).


Rear Projection

When video or slides are projected from behind the screen, in which case the projector(s) are usually backstage, out of view of the audience (and the image is electronically reversed).



A camera mounted video monitor that displays script and or notes, visible to the speaker or performer, operated by a person at a computer who moves the script, following the speaker.


Other Equipment:


ARS/ART/APT – Audience Response System/Technology or Audience Participation Technology

Generic terminology for audience polling, Q&A, and other real-time data-gathering technologies. While originally consisting of hardware keypads with buttons used for responding to simple polls, audience members can now use websites, mobile apps, or software embedded in their event app to respond to polls, ask questions, brainstorm, fill out surveys and more. Most ARS can display results almost immediately after input by the attendees.



The equipment used to hang truss, lighting, and power cables from a roof or ceiling. Not the truss itself, but the chains or motors used to suspend it.



Metal (usually aluminum) gridwork, often suspended above the stage or audience, from which lights, sound, or other equipment is hung. Sometimes can be used for screen surrounds, or used vertically with heavy bases to create “truss towers”, again for the purpose of mounting equipment to them.


Tech Riser

Technical Riser. A platform, usually located at the back of the audience area, where the technical crew and equipment that operate the show are located.


Production Terminology and Slang:


Bio Break/Going Bio – A “Biological Break”

AV slang for a bathroom break, usually on headset. You might hear the show caller say, “Take a bio, everyone” or your audio person say, “Going off headset for a bio.”


Call Time

The arrival time for technical staff. Make sure to set the call time early enough for your AV staff to be set and ready before your event. Just watch out for “turnaround time”, covered below!



The area of the stage closest to the audience in a traditional stage setup. Remember, these types of stage references go back hundreds of years and are always based on the point of view of the “actor”.


Front of House/FOH

Traditionally everything on the audience side of a theatre proscenium (the wall between the audience and “backstage” where the curtain usually falls). In most meetings and events, there isn’t a proscenium unless you’re using a venue with built-in stage, so the front of house covers everything on the audience side of the stage, projection screens, or pipe and drape.


Green Room

A backstage area for presenters, performers, hosts, etc. to relax in or prepare for their performance. Frequently the green room will include couches, chairs, lamps, and video/audio monitors so the guest can see and hear what’s happening on the stage.



Technically refers to the entire venue of the event (“Check with the House and see when those chairs are being dropped,”), but is often used as slang for Front of House (“Go out in the house and see if you can find the catering manager”).



In a theater, the proscenium is the opening in the wall at the front of the stage, usually where the main curtain is hung.


Run of Show – AKA Show Flow, Show Call

The document used primarily by the show caller (sometimes referred to as Stage Manager) to keep track of audio, video, lighting, and other cues contained within a meeting, event, or production. Often distributed to the rest of the crew to follow along.


Site Visit/Site Survey

While planning an event the producer, client, and representatives from the venue meet at the venue to discuss layout and logistics. Sometimes called a walkthrough.


Stage Left and Right

The left and right sides of the stage, from the performer’s perspective, facing the audience.


Turnaround Time

A US union restriction (though not exclusively) that requires technical staff to have a certain amount of time off between when they leave at night and when they have to arrive at the venue in the morning. Requiring staff to stay extremely late and return early in the morning may cause the entire next day to be paid overtime, so be sure to ask about turnaround time when setting the schedule for your even setup, rehearsals, and show.



The area of the stage furthest from the audience in a traditional theater setup. Another one of the stage definitions that have been around for hundreds of years, and is always from the viewpoint of an actor facing the audience.


In Conclusion

So what did we miss? We tried to hit the most common, and often least understood, terms. Do you have a story about not understanding something your AV crew was talking about? Share below!



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