AV Terminology: An Event Planners Guide

AV Terminology: An Event Planners Guide

Every industry comes complete with its own set of secret codes and distinctive terms. From acronyms and abbreviations to common words that take on their own specific meaning – cross industry communication can often prove difficult when you’re effectively speaking a different language.

The world of event production and AV is no exception. As much as we try and communicate clearly with all our clients, we can all be guilty at times of assuming understanding. So we’ve decided to put together a series of posts that explain the most commonly used terms in the world of event AV. In this first instalment, we take a look at three terms we use time and time again, offering our definition of each and, most importantly, explaining why a level of understanding is key to ensuring event success.

Aspect Ratio

When we talk about aspect ratio, we refer to the proportional relationship between the width and height of a screen or image. The two main aspect ratios found today are the once standard 4:3 and the now more commonly used widescreen 16:9. The first figure relates to the screen or image width, with the latter referring to its height.

Why it matters

If you’ve ever seen a 4:3 presentation on a 16:9 screen or vice versa, you’ll understand why ensuring you work to the correct aspect ratio is important. The term ‘letter box’ or ‘pillar box’ refers to an image that does not fit the screen correctly and as such is enclosed by black lines either side. For a 4:3 image on a 16:9 screen, these lines appear vertically. For 16:9 on 4:3, horizontally. Either way, these black lines prevent maximum screen use and pose a distraction for your audience.

Your other options are to crop or zoom, in which case you may lose valuable content, or to stretch, which results in distortion and poor image quality. So make sure you know the aspect ratio of the screens in use and that everyone involved in the preparation of presentations and visual aids is on the same page.

Front and Rear Projection

The main difference between front and rear projection is self-explanatory – with the former, images are displayed via a projector placed in-front of the screen, whereas with the latter, the projector is situated behind the screen. Whilst this may seem like a choice that bears little consequence for your event as a whole, there are some important points to consider.

Why it matters

Your choice of either front or rear projection will impact both the aesthetics of your event and the useable room space within your chosen venue.

Opting for rear projection allows for a cleaner look, with the projector itself being concealed behind the screen, and also allows for presenters to move freely across the stage without fear of blocking the image source. It will however mean that your staging area will need to be set at a distance from the wall of the room. How far into the room your staging sits will be dependent on the size of your screen and the appropriate distance needed for optimum projection – the further in your stage, the less usable space you have to accommodate your audience.

Front projection allows for the screen to be flat against the wall, offering optimum audience space but presenting the downsides of possible noise pollution from the projector itself and the risk of interference between the screen and image source.


Successful events are increasingly reliant on efficient use of digital technologies, so a basic understanding of bandwidth is highly beneficial. Commonly measured in Megabits per second (Mbps), bandwidth refers to the amount of data that can be received (downloaded) or sent (uploaded) in the given time frame. In most cases, the download bandwidth available will be greater than the upload, as most user activity involves the downloading of data.

Why it matters

The experience your event attendees have will be hugely reliant on the bandwidth available. On a basic, personal level, they will expect to be able to access the internet with ease and relative speed. In an age where almost all of us carry more than one digital device, our bandwidth demands are increasing – the higher your attendee figures, the more devices on site and the greater your bandwidth needs.

And that’s before we even take into consideration the event program itself. Live streaming, online registration, social media, event apps, webcasting, live polling; there are an increasing number of activities that are reliant on sufficient bandwidth. If you’re hosting a hybrid event that connects multiple sites through a hub location, ensuring all venues have the right capabilities is crucial. Your AV or event tech provider should offer advice in this area but arming yourself with an understanding of your requirements is a hugely useful step towards ensuring you select the appropriate venue for your event.

Keep your eyes peeled for part two in this series, where we’ll be explaining some of the key AV techniques implemented today and how they can be used to enhance your event.

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