Media, Audiovisual, Video and Audio Works and Displays

You are working on the development of a touring exhibition that involves an Audiovisual (or AV) element. It could be because this is the medium of an artwork, for example an artist’s video. You may be making a curatorial decision about content, such as whether to include an interview with a designer in their studio, or a historic film, which adds another dimension. It could be a design choice to improve the flow of the show, or appeal to a particular target audience. Or it could be a combination of any of these things. Each of the above reasons will be the start point for different practical questions, many of which need to be thought about together, many of them interlinked.

There are lots of different ways that video, audio and other electronic media can be used within exhibitions.ⁱ This chapter is a brief introduction to some of the technical considerations that you will need to make when including these types of works and displays in an exhibition. AV design and installation is a specialist area, so throughout there is a focus on how to communicate your needs to other people, including specialist consultants and gallery technicians. There will also be a specific reference to some of the ways touring a show affects the decisions you make.

Throughout the chapter AV is used as a cover-all term. There are many different types of AV and media content, for example: original video artwork, documentary or informational videos, archival film or TV footage, animation, sound installations, computer games, web-based work, electro-acoustic sound work, interactive displays, 3-D printing, touch screens, electronic objects, electro-mechanical sculptures and many others.

At this current time the screening of video is one of the most common forms of AV media experienced in exhibitions and for this reason it will form the main focus of this chapter. Nevertheless many of the same general principles, questions and thought processes apply to the display of other types of media work.

Important start points:

1. Don’t panic! Information and conversations about AV equipment often come with lots of specialist technical words, phrases and lists of numbers; some of these are important and useful technical terms and specifications, some are marketing hype by manufacturers to make their kit sound more advanced or unique than another’s, and some are unfortunately used by people who want to sound clever. All of this can be very confusing. As a general rule when you need to find something out or ask questions about AV equipment it is more important to be clear and describe the things you do know and understand rather than those you don’t. That said some of the basics, once grasped, are much simpler than they might first appear. So following this:
2. If you don’t know, ask someone who might! If you are at any stage of commissioning or designing a new touring exhibition it is a really good idea to consult an AV specialist who works in the exhibition world. They will have the experience and knowledge of the field to select and integrate the appropriate equipment and help you develop your ideas. There may be a perception that this approach will be more expensive, but it is likely that their knowledge and expertise will save you time and money in the longer term. When talking to them though:
3. Don’t pretend to know more than you do! It is much better to explain what you do know rather than what you don’t. It is much better to be specific where you can. Finally for now:
4. By the time you read this information, some of it may well be out of date! AV technology changes at a rapid rate, much the same as with computing technology Moore’s Lawⁱⁱ can be seen to apply. Manufacturers, inventors and others are continuously pushing new ideas and equipment out too. For this reason, no specific models or brands of equipment are mentioned in this chapter. Next year they might not exist.

What have I got and what do I need?

Very often decisions about AV work and equipment involve some sort of compromise. The important thing is to start with what you know, and use this to determine which of the parameters you are working with are fixed and which are more flexible. Certain of these parameters might be physical, for example the height of a gallery wall or the way a piece of technology works. Others may hold a range of options that might also weigh up against something else, for example, whether you hire or buy equipment and the relative costs involved. Knowing what you have, what the situation is and what you want will enable you to find out what the possibilities are and to get the best from the work.

Here is a simple set of questions that are a good place to start working out what you already know:

1. What is the work?
2. How do I want to display it and/or how does it need to be displayed?
3. What are the venues, what are they physically like, what are the situations in each?
4. What is my budget and how do I best spend it?
5. How do I manage the AV part of the tour?
6. Anything else special?

Throughout this chapter each of these questions will be expanded and explored.

AV in touring exhibitions
A touring exhibition will visit multiple venues, all of which can be very different both in scale and feel. Because of this planning a touring exhibition involves additional thought about the AV elements. Whilst thinking about the questions outlined above you will need to ask some of them multiple times. For example, is the equipment able to do what you want it to do in each different space? Where do you put the equipment at one gallery as opposed to another? Depending on the potential issues and your options this could involve multiple solutions for each venue or it could, for example, involve designing the exhibition around a set of mobile exhibition furniture pieces that can house the equipment. Each question needs to be considered with all the venues and situations at those venues in mind.

ⁱ Electronic media are types of media that require the use of electronics or electromagnetic energy to see, hear or otherwise experience the content.

ⁱⁱ Moore’s Law is the observation named after Gordon E. Moore, co-founder of the Intel Corporation that the number of transistors in an integrated circuit doubles roughly every two years. Originally a prediction it has proven to be accurate and is also now used as a guide for how electronics manufacturers set their targets.

In most AV work, the content and the method of display are separate things, with the content being stored on some sort of media. Until recently, video content would most likely have been held on DVD. With some works this is still the case, most commonly media content is now stored as a digital or computer file. This is not always the case. Sometimes the display and media are physically intertwined ⁱⁱⁱ. This is usually only in specific artworks, displays or inventions.

How you decide to show the work is generally led in some way (or sometimes completely) by the content, so it is important to first find out the parameters of the content.

If the work is part of a collection it will likely come with a Certificate of Authenticity. This should include information about the format and media. Additionally, there may also be a set of Conditions of Display, which will make further specifications about how the work should be shown (we’ll come back to this). You could also ask the film maker, artist or production company directly about the work.

The main questions you looking for answers to are:

1. How long is the film?
2. What is the aspect ratio? (This is the shape of the video – the ratio of the width to the height)
3. Is the audio stereo, mono, 5.1 surround, or other?
4. What is the resolution? (The pixel dimensions ? for example 1920 x 1080 pixels is Full HD)
5. What format is the video/film currently in? (For example, is it a disc or a computer file)
6. Is there anything special? (For example, is it a multi-screen synchronisation?)

Knowing the answers to the above, will enable you and your AV consultant to have a better idea about the quality of the film and help determine the best means of playback, and to help select the right equipment for the installation of the work. You might not be able to find out all of this information, but the more you do the better.

Often multiple versions of video work exist. It is usually best to either get an approved exhibition copy, or sometimes better, a copy of the master file in a high quality format in order to have an exhibition copy created.

Playback of content

At the time of writing, memory card based media players are the best solution for high quality, reliable and economical playback of video and audio. Professional media players are designed to be robust and be usable for 24/7 playback, in a way that DVD players are not; this makes them ideal for touring exhibitions. They can handle most video resolutions and frame rates, and can operate with a whole range of equipment. They are also usually small and therefore easily concealed within the exhibition.

The video content may not be formatted to work with a media player, or it may be formatted in a way that is specific to a player that is no longer available or you don’t have in your own equipment stock. To get it to work properly, the video will need to be transcoded (this is the term for this sort of format conversion). This is why you need the high quality format of the file – a good source file treated properly results in a good exhibition copy.

If the work exists as a hard copy (for example a DVD or tape format), unless it is integral to the work or the exhibition that it is shown in its original format, it is highly advisable to have a media player compatible version of the work produced. This is particularly the case with touring exhibitions, where they may be used continuously for long periods of time. Again it is best to locate the highest quality source possible. Depending on the source, this may then involve processes of tape conversion, DVD ripping or telecine conversion.

Knowing the answers to the questions about the content will help you determine what you need to do with it. And this will also help you be able to find out the costs involved.

Sometimes media players aren’t the best way to show a particular video. This is usually because of specific reasons to do with the content. Instead, it may be possible to use a computer. Small and micro-form factor computers such as the Mac mini small and the Intel NUC are particularly useful for this.

Computers can run specialist programmes directly, play films in different formats, can be integrated with other pieces of technology and often have other additional features that can be used. However it is worth noting that computers are not dedicated to playing video in the stand alone way that media players are – even when set up correctly they still behave like computers. This means they may request automated software updates or behave in other unpredictable ways. Computers need more monitoring to check they are running correctly.

Some flat panel displays and screens have internal media players. These can be very useful in an exhibition as equipment and cabling is kept to minimum. It is worth noting that only professional displays have media players that are suitable for exhibition playback. Consumer grade screens usually have a feature that makes them less suitable (often this might be a message that says something like ‘Repeating Film’ or a menu that comes up).

Some artworks and displays involve the synchronisation of multiple videos together. There are a number of ways to do this using both media players and computers; this is quite a specialist area and it will be necessary to refer to an AV consultant or someone with specific experience.

Installation of playback

Here are two key exhibition design questions about playback:

• Where do I put the playback?
• Who is going to be turning it on and off?

Both questions are interlinked and depend on the specific exhibition and venue. Ultimately, the important questions are about the simplicity and reliability of the playback.

There are arguments for and against having the playback local to each piece of equipment or in a centralised location. The amount and length of cabling can be a determining factor. It also depends if everything needs to be connected together, for example in a multi-screen synchronised work or where sound is split between different exhibits for some reason. If there are lots of pieces of equipment in a large venue it can be very time consuming to turn everything on. An extreme example of this would be the exhibition Digital Revolution organised by Barbican Touring Enterprises (launched at the Barbican Centre in 2014), which as an exhibition entirely made up of AV exhibits, takes two people an hour each day to turn everything on.

Having a completely centralised playback system can make the whole thing very complex and mean that only a specialist can solve simple problems. Unless otherwise unavoidable (for example in a show like Digital Revolution) and especially in touring exhibitions it is always a good idea to keep a setup as simple as possible. Once an exhibition is running it will be manned by invigilators and in-house staff who may have limited knowledge of AV equipment, so this needs to be taken into consideration (see section 5 of this chapter for more information).

ⁱⁱⁱ For example Cory Archangel’s HITACHI P42H01U Plasma Burn, 2007 where the label information about the artwork is ‘burned’ permanently into the plasma screen that forms the artwork. http://www.coryarcangel.com/things-i-made/2007-033-hitachi-p42h01u-plasma-burn

Understanding the format and content will help you and your consultant determine the appropriate equipment on which to display the work. But before you do that, you need to know whether this has already been decided or not.

As briefly mentioned, in section 2, about content, if the work is part of a collection it will likely have a Certificate of Authenticity. If there are any Conditions of Display (other terms may be used for this) attached to this document they might already outline what the options are. This is much like any work or object that comes with a Certificate of Authenticity of Conditions of Display, although the details will be specific to video.

In some cases the way in which the work should be shown is implicit and evident in the work. For example artist Bruce Nauman’s Violent Incident is always shown on 12 televisions stacked in a specific 4 x 3 format.^iv

Even single screen projection works can sometimes have very specific instructions about the type of equipment that can be used, any special features it must have or the way it must be installed.

The work may also come with a Technical Manual or Technical Rider. This may not be as legally onerous as the Certificate of Authenticity. Depending on the artist, studio or production house these could be rigid instructions that must be followed to the letter, or loose guidelines. If any of these documents contain reference to specific models of equipment (with model numbers etc.), or lots of equipment and details, it is worth finding out the degree of flexibility in terms of acceptable alternatives. This can have implications to both the feasibility and budget of showing a work.

The work could also be new, either independently produced or commissioned directly for the exhibition. In this case there is likely to be some discussion about the options for output.

Whether determined by a document already, or if you have free rein of choice, the basic options for the display of video work are whether to show the work on a screen or projector (or multiples of each).

Screens and flat panel displays
At the time of writing, the predominant form of screen are the various combinations and types of LCD/LED backlit monitor – from smart phones, to tablets, mid-sized TV displays and various large formats. It should be noted that although these screens contain LEDs and are sometimes marketed as LED TVs, the image is created by an LCD panel and the LEDs are used to create the backlight (previously slim-line fluorescent tubes were used to create the backlight). True LED display panels, where LEDs are used to create individual pixels, are a different type of display technology. LED panels are generally used to create much larger format screens, for example video walls, signage or very large screens such as those as concerts and other events. To make it more confusing though, there are other LED technologies, for example OLED, that are used to directly generate the image on some large TV sized screens (particularly the high-end curved type) and some smaller displays, such as those found on some phones and digital cameras. OLED is short for organic light-emitting diode; these are a different type of LED that can be used on a much smaller scale to create pixels. Currently, the LCD/LED combination remains the most available, economical and widely used screen technology.

Professional VS consumer screens?

The market for consumer branded screens is highly competitive and the number of TVs purchased by people for their homes is huge (sales of £2.8 billion were recorded for 2013 alone ^v). With the exception of high-end varieties, consumer grade screens are comparatively more affordable than the professional versions. However, they are not always the best choices for exhibitions and especially touring exhibitions.

Consumer screens often have extra logos, shiny silver edges – if that’s this year’s trend – and curvy details. They are also designed for consumer use, so the functionality will be geared more towards things like home streaming.

In general professional screens will be designed to look aesthetically neat, with slimmer frames, more discrete logos and added professional functionality in the menu. Very importantly they will be designed for long-term continuous use. This will mean they will often also come with a warranty for specific duration of use, for example 16 hours a day or even 24/7. They may also come with other features including internal media players or the ability to create a video-wall.

Technical notes about screens

Size: Screens come in a range of sizes; their measurement is given diagonally in inches. Certain sizes of screens are more common than others and for that reason tend to be more economically priced, for example 32″ or 40″ diagonal screens. It is possible to get screens over 100″ (Panasonic currently make a 152″ inch plasma screen); these can be enormously expensive though. Larger screens can be heavy and will also need additional consideration for how they are installed. You may also need to think about the logistics of transportation.

The size of a screen has a direct relationship with the viewing distance – the larger the screen the better it can be seen from further away. Visitors to exhibitions will experience far wider viewing angles than with home viewing (where there are some recommendations for angle and distance). In exhibition design there are no absolute rules for this, smaller screens can be used to draw visitors into a display area, or the size of the screen could be chosen to balance against an object or text panel.

Aspect Ratio: The aspect ratio is the shape of the screen (the ratio of the width to the height). At this current time, all TV sized LED and large format screens (and almost all smaller screens) are in the widescreen 16:9 aspect ratio format. If your work is 4:3 aspect ratio – this could be because it is archive footage or this could be an aesthetic choice – the screen will have black areas to the left and right of the image. This is called ‘pillarboxing’.

An important exception to the current trend for screens to be manufactured in the 16:9 format are iPads and some other tablets. Conversely to larger screens, these are produced in a 4:3 format. This means that if you use an iPad to play a 16:9 film in your exhibition, the screen will have black areas to the top and bottom of the image. This is called ‘letterboxing’.

Resolution: Unless the screen is particularly cheap, most screens will now be at least Full HD resolution. The resolution of a screen is its pixel dimensions, for example Full HD is standardised resolution of 1920 x 1080 pixels.

In addition to the ‘native’ resolution of a screen (this is how many pixels it actually has), different screens will also accept other different resolutions. The HD Ready certification for screens for example, is an indication that the screen will ‘accept; an HD resolution into one of its inputs. The screen itself might actually be a lower resolution.

Already Ultra-High-Definition (4 times the resolution of Full HD ^vi) resolution screens have become available in the consumer market, along with various professional versions of this group of resolutions. There are a number of different standards for UHD and 4K resolutions.

Other details: Bezel width is the size of the frame around the screen; higher end professional screens tend to have the smallest bezel. The smallest bezels are currently just a few millimetres thick (at the moment these are very expensive).

Different screens can also have either a matt or gloss finish to the glass surface. Partly this is an aesthetic choice, but it will affect how reflective the screen is.

Installing monitors/screens

Screens can be very useful within touring exhibitions. The image they produce is integral to the display unit and there is a wide range of options in the different ways that they can be installed. This can be particularly useful if it is difficult to control the light levels in the gallery. They are usually fairly simple for a gallery or museum technician to install. There are 3 basic different ways to install a screen within an exhibition:

• Using a wall bracket, they can be fixed to a gallery wall or exhibition structure. Most screens conform to standard bracket formation called a VESA mount, which are interchangeable with different screens and come in a range of sizes. Special attachments mean these brackets can be connected to ceiling drops.
• A table stand fitted directly to the screen can be used to locate them on a plinth, table or other exhibition furniture.
• Special floor stands can also be used, where the screen needs to be in the middle of a room or they need to be mobile for some reason, i.e. a temporary event, or for a particular aesthetic choice.

Commonly, a standard museum eye line (somewhere in the region of 150 – 160cm from the floor and depending on the house style of the venue) is used to determine the centre line of the screen. Screens can also be lower if they are intended to be viewed from a seat or displayed as support material to an exhibit.

Screens can be used in most of the lighting conditions found in galleries and museums. However, for brighter environments a professional high brightness screen will be needed. There are also many types of specialist screens, for example those made for outdoor use or direct sunlight. As these are produced for specialised markets these tend to be very expensive.

Video projections

Video projectors make images or video appear onto a surface; they use light from a lamp in combination with a lens and an imaging device to project the picture. There are many different models of video projector ranging from small pocket sized portable devices (costing a few hundred pounds) to very large cinema and event projectors that can be used at very large scales (these cost tens of thousands of pounds or more).

In order to find out what sort of projector you need, you will need to determine and look at what you do know about the work and the different spaces.

Projectors are amazing pieces of technology but they are not magic, whatever projector you are using there is almost always some sort of compromise. This is because projectors are completely dependent on the space and the light in that space to determine how well they work – the compromise is with your location.

Projectors use radiant light to make images and so the projected image is also affected by other sources of radiant light – a cinema space is completely blacked out because a dark room is the optimum condition for a projection.

A simple rule for projectors: in order to see the image from the projector the projected light must be brighter than any other light source in the same area.

A second rule for projectors: the sun always wins. Direct sunlight is just too bright for any projector to even attempt to compete. (If trying to produce a video image in direct sunlight you will need to look at high-brightness displays and LED walls).

A third rule for projectors: everything is a balance of factors = how much ambient light is there in the space? What is the projection surface? What else is in the same room? Are the images high, medium or low contrast? Are they colour or black and white?

Installing projectors
Here is a list of questions to ask when planning the installation of a projector:

• How big is the image you would like?
• What is the throw distance? (This is the distance between the projection surface and the lens)
• What is the room/space like?
• What are you projecting on to and is this front or rear projection?

How big is the image you would like?

There is a direct relationship between the size of the image you want and how bright the projector will need to be to make it properly visible. The brightness of projectors is given by its rating in Lumens.

When discussing the image size with an AV consultant, it is much better to be as specific as possible, even if you don’t know the exact size you want. For example saying, ‘somewhere between 3 and 4 metres wide’, is more useful than a vague statement like ‘quite large’.

As with screens, the central mid-line of a projection is often at, or near to, a standard museum eye-line height. With larger images though, the relative sizes get too great for this to be possible. The sizes of projections are also often decided based on physical dimensions on the room or space.

Throw distance: How far away you position the projector will determine how large the image can be, and conversely the size of a room or space may limit those options. Projectors output the image through a lens. Lenses have a range of zoom and of focus. Most projector lenses have a zoom ring, which can be used to vary the size of a projection although some projectors have no zoom.

With a ‘standard’ zoom projector lens, a good rule-of-thumb for a ration of throw distance to image width is around 1:2 (e.g. to achieve a 2 metre wide image you need at least 4m between the projection and the lens). A ‘standard’ lens a generic term for a lens that comes attached permanently to a projector.

Larger installation projectors will have the option to fit different lenses, these can decrease the throw distance or, if required, increase it.

Some projectors are designed to have naturally short projection throws. These are often known as Short Throw projectors, where the throw ratio can be as low as around 1:0.5. Usually these have the limitation that they have a ‘fixed’ zoom, which means that in order to make the image larger or smaller you have to physically move the projector back and forth.

What is the room/space like?

The most important aspect of this question is – how much light is there in the room? This is very rarely specifically measured, more often; a general idea is enough to make a judgment.

Understanding the number of windows in the room and if there are any other works in the space will enable an AV consultant to get a good idea. Direct sunlight is always a problem ^vii. Key questions include:

• How much can the light be controlled?
• Can black-out material or temporary exhibition walls be used to cover windows and skylights, or create a ‘light-lock’ in front of the doorway to a space? What are the walls like? Can they be used for the projection surface? Most standard matt white gallery walls create a perfectly acceptable projection surface.

What are you projecting on to? Front and rear projection.
The colour rendition and the brightness of an image are partly dependent on the surface used to display the image. All screens have different qualities in terms of gain (how much they boost or decrease the brightness), contrast of the image and viewing angle.

Front projection is a term that describes where the projection surface is opaque and the image is seen as reflected light from the surface. Most commonly in exhibitions, this will be on to a section of gallery wall or a fabric projection screen. Front projection means that the projection cone (the path of the light) will be in the same space as the viewer, meaning that it’s possible to create shadows on the image if the viewer gets in the way of the light path.

Rear projection is possible where a surface is partially translucent. It is only really effective with a dedicated surface because these are designed to pass light in the correct way (although other surfaces can be used to creative effect). Generally, rear projection means that the projector is out of the way of the viewer. However, this means that space for the projector will be needed behind the screen. Although rear projection can potentially create very high quality images, it is important to select a material and consider projector positioning in order to minimise ‘hot spotting’. This is where the focal point of the projector beam is seen by the viewer as a brighter area of glow than the rest of the image.

Physical installation of projectors

Projector axis: The axis of a projection is a notional perpendicular line at the centre of a projection screen (or other surface). Most projectors are designed to be ‘off-axis’. This means that if the projector is sitting on a table top the projector will be roughly in line with the bottom of the image. If the projector is hung from the ceiling this means it will be roughly in line with the top of the image. The amount that a projector is ‘off-axis’ from the perpendicular centre is called the ‘offset’. There are no rules for this as all projector models are slightly different! Some projectors and lenses are ‘on-axis’; these tend to be short throw lenses intended for rear projection use.

Mounting projectors: All projectors are designed so that they can be installed with the body of the projector either way up and have a function in the menu that means you can digitally flip the image horizontally. This means you can use the ‘offset’ of the projection to minimise the amount the projection cone (the path of the light) interrupts the space, thereby minimising the chance of shadows from viewers in the space.

Usually projectors are mounted so that the shadows caused by viewers interrupting the projection cone are minimised. When considering projector positions it is also worth bearing in mind any other physical objects that could interrupt the light beam – for example gallery lighting, cables for suspended artworks or other projectors. When multiple projectors are used in the same space the light beams from different projectors can cross without any problems.

Projector brackets can be used to fix the projector from a ceiling. Projectors can also be positioned on purpose built shelves. They can also be fixed on to or inside of plinths or mounted on other aspects of exhibition furniture.

All projectors require good ventilation. Projector lamps generate a lot of heat, which needs to go somewhere; almost all projectors have fans with an air intake and an air exhaust (there are a few specialist exceptions to this). A projector will need space around it to enable this air flow; they cannot be completely boxed-in. Care needs to be taken to make sure that hot air from the exhaust doesn’t recycle direct into the intake.

Projectors don’t like dust. It’s a good idea to keep projectors away from dusty areas – for example, a gallery during a wall build with sawing and sanding. See the maintenance section of the chapter for more information on this.

Lens-shift and keystone correction: If you want to position the projector outside of its axis you will need to use one of these features to make sure the image isn’t keystoned. This is where the image becomes trapezoid, like the ‘keystone’ in a brickwork arch. Generally this is not desired (although it is used on purpose and to effect in some installations); we tend to like watching videos with nice right-angled corners. To counteract the keystone effect there are two options: lens-shift and keystone correction. Not all projectors have either of these features. Lens-shift is a feature usually only found on more expensive ‘installation’ projectors. Each model of projector will be different.

Keystone correction (and also cornerstone correction) is a digital correction; the actual physical projection will still be trapezoid but the image inside will be ‘pulled’ into the correct shape. The digital black around the projection will still be somewhat visible – the black is still made from light. This depends on the ambient light, this is one instance where slightly more light in a space can sometimes be beneficial. The higher the ambient light, the less our eyes see the difference in the contrast between the image and the black around it.

One more commonly used solution to digital black image edges is to paint a dark colour around the actual image. This is usually enough to make it not noticeable. Another solution is to project on to a screen, so that only the image hits the screen. In this instance the digital black edges will be projected into the space so this only usually works if the walls and floor are dark coloured.

Lens-shift is an optical feature of a projector that enables the user to vary the amount of ‘offset’ from the axis. The lens moves up and down (and also often side to side) to a certain amount meaning that you have greater flexibility in the position of the projector whilst the projection remains a true rectangle.

16:9 and 16:10: At the time of writing, most videos are produced in the16:9 format. This is also the current format that most television is produced in for the BBC and other broadcasters. Projectors however, are not always 16:9. Some projectors, particularly all larger projectors, are 16:10 ratio. This means that in order to show 16:9 footage at the true ratio of 16:9, there will be a small line of digital black at the top and bottom of the image.

One solution to this is to allow the projector to fill the whole area and to show the video in 16:10. This involves a small amount of digital stretching, which sometimes can work, but can also be noticeable and also sometimes not acceptable as it involves a distortion of the work.

The other options are the similar to the solutions to the problem of the digital black edges around a keystone corrected projection (see above).

Some projectors also have a digital shift feature that means that the 16:9 image can be shifted digitally to the bottom or top of the 16:10 projection. This can then sometimes be ‘lost’ in the ceiling, off the edge of a screen or into dark carpet.

^iv www.tate.org.uk/art/artworks/nauman-violent-incident-t06732

^v www.mintel.com/press-centre/technology-press-centre/tv-market-back-in-growth-for-the-first-time-since-2009-and-more-than-half-of-tvs-sold-are-now-smart

^vi This depends on which type of 4K. At the time of writing, there are a number of different standards, each being applied in different situations. For example, DCI 4K is used in the movie industry, which is different to the UHDTV standard.

^vii To my knowledge at the time of writing, there is no such thing as a ‘Day Light Projector’.

Many, although not all, video works have some sort of sound. Unfortunately though, the sound part sometimes gets left as a bit of an add-on when it comes to the exhibition presentation of the work. This is sometimes true even with works that are sound alone.

The difficulties with sound are largely a result of the fact that galleries and museums themselves are often less than ideal spaces for the presentation of sound. They are generally very acoustically reflective spaces – the large flat walls, hard surfaces and sparsely filled open rooms mean that sounds travel and bounce around easily in these environments. This can often present a challenge for showing even a single work with sound (although some works specifically benefit from or are developed to make use of the reverberant qualities). A further challenge is found when showing multiple video or audio works in the same space.

In contrast to the acoustically ‘live’ gallery space, videos and sound are often edited in smaller rooms, where there is a degree of control over the sound quality (sometimes even with professional acoustic treatments) or also the sound is mixed on headphones. In these edit rooms, there is generally a great deal of control over the detail of the sound and the ‘physical’ effects are minimised.

There are two main things to consider with sound: firstly, the intelligibility of the sound when it is played in a space – essentially how well can you hear it properly. And secondly, sound bleed – this is both in terms of how much the sound from one work interferes with other works in the same space and also how it affects adjoining spaces.

Sound and acoustic design are topics that can by necessity get specialised and complicated quite quickly (and full of equations and scientific principles). This may be one of the reasons it is often passed over, or given limited consideration, in gallery and exhibition design. Fundamentally though, some of the truly effective ways to improve the sound quality of a space are also very visually imposing – by their nature in order to be effective, they can take up a lot of space. And as always budget can be an issue.

In the context of a touring exhibition, these issues are compounded. It is rarely appropriate to create the equivalent of a small cinema to show each film. There are things that can be done though. And some of them are quite straightforward. In keeping with the rest of this chapter it is assumed that the sound is coming as part of a video file.

This following statement may seem obvious, but it’s worth just making sure: In all cases involving sound, in order to hear the audio you will always need an amplifier of some sort and a loudspeaker of some sort (headphones are a type of speaker).

Mono, stereo or multi-channel sound: The terms mono and stereo will be familiar to most people. What they describe is where the sound is coming from – the directionality of a sound recording.

Mono sound: A mono recording could be said to have a single ‘channel’ of sound, this means a mono recording will appear to come from one place. If you play a mono recording through a pair of headphones it will appear in the middle of the two earpieces. A mono recording will remain mono even if played out through multiple speakers; in this situation the sound played out through each speaker will be exactly the same.

All audio amplifiers and speakers are capable of outputting mono sound. However, it is not usually a good idea to run an amplifier at volume with any of the speaker outputs unconnected to a speaker. This can actually damage the amp. Some amplifiers have a special mono or bridge mode that can be enabled to avoid this problem.

Stereo sound: A stereo recording has two ‘channels’ and will appear to come from somewhere between two places. These places are usually described as ‘left’ and ‘right’ as this relates to each of our ears and the space between is called the ‘stereo field’. Stereo is the most common format used to record sound; it enables us to replicate the experience we have of sounds coming from all around us.

A stereo recording is ideally played through two speakers in order to replicate the field that was created at the time of making. It can also be played out through a single speaker; in this case the two channels need to be mixed down to a single channel otherwise you may lose part of it.

A stereo recording can also be played out through multiple speakers, however, in this situation special care is needed to preserve the stereo field – if the left and right channels are mixed up for example, the spatial placing of the sound will be wrong. You may also get an effect called ‘phasing’ where some detail is even lost (or other curious phasing effects).

To add further options a stereo recording doesn’t have to be used as a left-right stereo field, it could also be used to create two completely independent sound channels.

Stereo amplifiers are the most common type usually available. Headphones are also almost always stereo.

Multi-channel/surround sound: Multi-channel sound is even more complex, but in its simplest form generally refers to a number of channels greater than two. The most commonly encountered forms of multi-channel sound are the various types of surround sound. This is where a number of speakers are used to create a more detailed spatialisation of sound, than with just the left and right of a stereo recording. The standard for surround sound is often referred to as the short hand 5.1 sound. These numbers describe the number of channels in relation to the field of speakers. With 5.1 sound there are generally 5 speakers placed around the listener – centre front, left and right front, left and right rear and a further single speaker dedicated to the low frequencies called either the LFE (short for Low Frequency Effects) or sub (short for sub-woofer speaker) channel. There are various versions of this sort of set-up including different 5.1 compositions, 7.1, 10.2 and many others.

With surround sound it is important that the speakers are positioned in the right places and that the listener is able to stand in the right place in relation to those speakers. The most common place you will experience surround sound is in a cinema where you sit in a seat pointing in the right direction. Much as with the seating arrangement in a cinema it is important that the listener is the right place when listening to surround sound in a gallery space.

You may also come across works with multiple channels that are not surround sound, where the channels/speakers are used discretely in some way.

In general if you have a multi-channel sound of any sort it is important to use the correct number of speakers for the correct number of channels in the correct arrangement. It can be possible to down mix a surround sound recording into stereo or mono but generally this must be done in the production phase in a studio to get the correct spatial detail and levels.

Playing sound in the gallery: why is it difficult?
To understand why sound can be difficult to control, especially in spaces like galleries, it is necessary to introduce some of the basic concepts about how sound works.

Sound at a distance – directivity: Sound radiates from its source as waves that lose their intensity the further they travel ^viii. In pure theoretical terms these waves radiate in all directions at once in a spherical pattern. In the real world though, different sound sources have different amounts of directivity and therefore have different patterns and shapes. A balloon popping, for example, does fit the spherical pattern (at least for all practical purposes). A person talking, on the other hand, exhibits a more hemispherical (half a sphere) directivity pattern centred around the mouth.

No matter how directional the original sound source might be, the sound will continue to radiate in all directions once in the open air. Sounds also travel very easily through air. This means it is very difficult to contain sound to a particular area.

To add further complexity the directivity of sounds varies over different frequencies – high frequencies are more easily controlled and directed, whereas low frequencies almost always travel in all directions outwards. As the frequency of the sound gets lower the size of the waves become physically much longer, so that they simply pass through many objects that might block higher frequencies.^ix

Generally if you want a sound to be loud in one direction, unless there is something stopping it, it will be loud in other directions too.

Sound at a distance – reverberation: What happens when one of these sound waves meets a surface? Each time one of the sound waves hits a surface, some of the sound is absorbed by the material of the surface and some of the sound is reflected. In general hard and/or very flat surfaces reflect more sound, whereas soft surfaces absorb sound.

The further away that you are from a sound source the more chance the sound has to reflect off other surfaces before it reaches you. Each of these sound reflections that are created will also radiate outward as a new point of origin and may then reach you. Only this happens at a slightly later time because the sound has to travel further from its original source.

Each of these reflections will then create further reflections each time it hits a surface, each of which then once again travel outwards in all directions. Luckily, as the length of the journey for the sound increases, its amplitude conversely decreases. Eventually they run out of energy and so we stop hearing them.

Unfortunately though, once again to make matters more complex different frequencies of sound are also affected differently by different materials. Essentially high frequencies are more easily absorbed than low frequencies. This means that the lower frequency reflections will persist in a space for longer.

The term used for the build-up and combination of these reflections is reverberation. Almost all galleries have a fair amount of reverberation. Clap your hands in a gallery space and you might well hear the reverberation continue for a second or even a few seconds until you really can’t perceive it anymore.

Reverberation actually tells us something about the space we’re in; the reverberation of a cathedral is noticeably different to that of a long corridor. At its best reverberation gives sound warmth and feeling. Most music recordings utilise real or more likely electronic reverberation effects to simulate the feeling of being in a particular type of room. At its worst reverberation affects the intelligibility of sound. And at its very worst it makes everything a wash.

Resonance and standing waves: As mentioned, sound waves have a specific length that relates to their frequency. When the length of a sound wave physically matches a dimension of a room or an object, the room or object then resonates in tandem with that frequency creating what’s known as a ‘standing wave’. That frequency becomes acoustically amplified as that frequency is bounced back
and forth.

Almost all acoustic instruments use resonance to increase volume. If you’ve ever sung in the shower, you may have noticed that some notes seem to be more powerful and resonate this is exactly what is happening, you’ve found one of the resonant frequencies of your bathroom.

All rooms resonate to some degree. Acoustically reflective spaces like galleries tend to resonate more. Rooms that are actually cubic suffer the most. Any dimension that is mirrored by another will increase the resonance at the same frequency.

If some sound frequencies (or notes, if there’s music playing) sound ‘boomy’, whilst others vanish, then it is likely the space you’re working in has a problem with resonance frequencies.

Improving the quality of sound in gallery spaces: We noted some of the properties of sound that can be problematic; now what to do about these.

A simple rule of thumb when positioning sound in a space: the closer you place the output to the listener’s ears, the more control over the sound you will have. Therefore, the very simplest solution for sound in gallery spaces is to use headphones.

Playing sound close-up: headphones: Headphones are a simple way to get the sound exactly over the listener’s ears. Headphones act to partly block other sounds out, so there are minimal interruptions and there are absolutely no reflected sounds as they contain the sound to a very local area (i.e. your head). This means they are ideal for when the intelligibility of the sound is very important. They are also ideal when it is important to reproduce a stereo field correctly. Headphones can also accurately reproduce mono sound; they can’t generally be used for multi-channel sound (with the exception of specialist surround sound headphones).

Headphones aren’t really heard unless you’re wearing them, so they are perfect for keeping the sound of a work contained so that it doesn’t disrupt other works in an exhibition. As an experience they can be immersive, but conversely sometimes isolating.

Headphones in galleries: One of the drawbacks of using headphones, is that exhibition visitors sometimes forget they’re wearing them and break them – it’s not their fault, they’re usually too engaged in the exhibition and the next thing they’re going to look at what their friend is pointing to and then they walk off’ the cable snaps, the headphones no longer work.

There are two sensible solutions to this problem: 1) in an exception to other rules, buy cheap, but buy lots of headphones so that they can be replaced easily at any time. Or 2) alternatively hire or buy much more expensive ruggedised headphones that are designed for exhibition use. These tend to have steel reinforced cables among other special features and because of this they will last a lot longer.

Speakers: Speakers are designed to project sound over a distance. The louder a speaker is, the greater likelihood of any subsequent reverb or room resonance. When using speakers here are some simple suggestions that help improve the sound quality and intelligibility:

Use mono sound: Mono sound is the easiest type of sound recording to control in a space, as there is only one sound to bounce around at any time. This is a solution often used for PA systems, particularly in reverberant spaces such as churches.

Bring the speakers closer: The closer you can get the speakers to the listener’s ear the better. The sound will have less distance to travel, so will need less amplitude to be heard and the less amplitude the reverberations will have. The idea is to make a smaller, localised area where the sound can be heard. This can work well, where a speaker is placed in a plinth or built into a bench and is particularly suited to touring exhibitions.

Use more, smaller speakers: This is similar to the suggestion to bring the speakers closer, but will create a larger area of sound, if more speakers are used. The individual speakers are still at relatively low volume, to increase the range add more speakers. This also works well in combination with a mono sound source. With stereo sound you have to be careful with the speaker placement in order to not mix the stereo field up. It gets even more complicated with even greater number of channels. Also, you need to be careful with impedance matching the amplifier to the speakers.

Equalisation: Where there are problematic resonant frequencies in a space, equalisation can be used to smooth out the sound. This is only really effective in the hands of someone with a good deal of sound experience or a sound engineer. The equaliser will need to be reset at any new venue.

Directional speakers: There are a number of different designs of directional speakers, each of which can be more or less successful and each with pros and cons. With all of these speakers the same general principle is true, as with all sound – the low frequencies are the most difficult to contain and direct. Because of this directional speakers usually cut or reduce the amount of bass frequencies in order to maintain the directionality desired. They can easily be incorporated into a touring exhibition design, but they are more expensive than standard exhibition speakers.

Parabolic dome speakers: These are usually made of a clear plastic that physically reflect the sound downwards (they are usually only used this way) and because of this they are sometimes known ‘sound showers’. They have a particular aesthetic look and are therefore not always appropriate. They work best when the floor directly underneath is more absorbent than it is reflective i.e. carpet is better than polished concrete.

Planar transducers: These have a 2 dimension diaphragm (unlike a normal dynamic loudspeaker that has a cone shape). This gives the sound they output a much flatter dispersion pattern. They are very suitable for all gallery situations as they can be made quite discrete, for example, a thin white panel that can be fixed onto a wall. They can be ‘pointed’ in in any direction, so are quite versatile; they tend to be more effective than the dome type.

The above are the most common directional speakers found in exhibitions, there are various other types used in various other situations, including line and other types of ‘arrays’, Ultrasonic Parametric Emitters and other even more esoteric inventions.

Reducing reflections the space: Where appropriate, sound absorbing panels, baffles, bass traps and other similar constructions can be used to reduce the acoustic reflections in a space. There is a general rule of thumb that in order to create an appreciable change in the room quality at least a third of the surface of the room must be changed in some way. Most of the truly effective constructions will be specific to a particular space. However, there are some more general ‘treatments’ that can be suitable for a touring exhibition.

Carpet and curtains can be used to some effect, although they tend to only affect the upper-mid and high frequencies, thereby leaving the lower-mid and low frequencies to continue to reflect. Curtains become more effective the thicker and more and wider the folds they have.

Simple sound absorbing panels can be much more effective. These can be constructed from a timber framework to make a four sided frame, acoustic grade mineral fibre should be held inside the frame and a fabric material (e.g. theatrical grade cotton or wool serge) should then be stretched over the frame. These can be hung on walls on batons or fixings. A quick internet search for ‘sound absorbing panels’ will find numerous designs for these, along with more sophisticated designs and solutions.

Isolating sounds in the space: In a touring exhibition, the same solutions that apply to reducing reflections also apply to lessening the interference of sound between different works and different spaces.

To truly isolate a loud work from others though, you will need to either select a space that is already well separated from others or construct a separate temporary space to physically contain the sound.

There are two basic principles for effective sound isolation. Separating wall should have a high mass – the greater the mass and the thicker the walls the better. And these walls should be designed to ‘decouple’ the separate spaces. As well as resonating within a room, sound resonates and is transmitted through materials (this is why you can hear your next-door neighbours). To stop the resonance something must be used to decouple or disconnect each side of the wall.

In a touring exhibition these types of constructions are rarely suitable. They are inherently more specialised and expensive to make than standard gallery walls. They will also not be cost effective to dismantle, transport and reassemble. They will also likely be specific to each venue.

It is possible to get some partial success with the use of heavy curtains, in the same way that they can be used to treat the reflections. The benefits are limited and any loud bass will certainly pass through.

It is therefore likely, that careful positioning of work and selecting an appropriate space will be the only solution for a loud piece of work in a touring show.

When thinking about isolating the sound of works the solution is only as strong as its weakest point. You can have thick stone walls, but if there’s an open door, the sound will come through.

^viii There is a rule called the Inverse Square Law that describes how waves loose power as they radiate. In very simple terms it says, that sound intensity is inversely proportional to the distance of the point of measurement from the source. Because sound radiates in a spherical pattern, the energy twice as far from the source is spread over four times the area.

^ix At the lowest end of our hearing, around 20Hz, the wavelength is almost 18m.

Signal and power cables are rarely desired as a visible part of the design of an exhibition. Although there are some notable exceptions of artists who like to have them seen as part of the work and some exhibition designs that have done the same, usually the goal is to hide them as much as possible.

It is important not to forget that they are necessary!

Analogue and Digital: There are two ways that signals are sent through cables: analogue and digital.

The cables themselves are all essentially different arrangements of copper wire, the end of the cable (or connector) will tell you what type of cable it is. At the time of writing and generally speaking, you are most likely to use digital cables for video signals (where lots of information about HD pictures needs to be transmitted). This would be HDMI, DVI and sometimes Display Port cables. Analogue cables are still generally used for sound.

In some situations, it is both desirable and sensible to have any interconnected equipment as close as possible to each other, for example a media player and a screen. This enables the cables that connect them together to be as short as possible. In other situations, it can be appropriate to have longer cable runs to a centralised control point. Both methods work, the decision to use either depends on what access you (or others) need to the equipment, the space that’s available in the gallery and the cost of cabling among other choices (see section 1 about playback for more information on the various options).

Cat 5/6 ethernet: For particularly long cable runs Cat 5 or Cat 6 extenders can be used for a more cost effective solution (particularly for very long runs that would otherwise require fibre-optic or other expensive solutions).

At the time of writing, the HDBaseT standard of receiver and transmitter can run HDMI or DVI signals up to a distance of 100m and at resolutions up to Ultra High Definition. The devices themselves are not cheap, but they can be very useful for touring exhibitions where there are either long or varying cable runs at different venues. The Cat 5 or 6 cables are relatively economical.

As with almost any situation involving money, there is always a balance between ambition and budget. When planning a touring exhibition involving AV equipment there are some specific points to consider.

Hiring or purchasing equipment

Purchasing equipment: In some situations it makes complete sense to purchase any equipment you will need; the duration of touring exhibitions often makes this a sensible choice. This will give you consistency and control in how the work is shown. However, when calculating the total budget, it is also important to factor in any ongoing costs alongside the initial outlay. These costs include ongoing maintenance (covered in more detail in the next section) and consumables such as projector bulbs.

Projector bulbs generally cost a few hundred pounds (or more) to replace, depending on the model. This will need to be done every 2,000 hours or so. For a long running touring show, durations like this and higher may easily be reached. At the time of writing, there are now a number of newer LED, LED/laser hybrid and other similar projectors on the market. In their current form, these projectors can run for 20,000 hours, or even more, before needing to be re-fitted. It’s worth noting that the initial outlay of these types of projectors is higher than those with standard bulb technology. The technology is still in its relatively early stages and in some current models the colour rendition and detail of the images isn’t quite up to the standards of the higher end UHP and Xenon lamp projectors.

If you purchase equipment you will need to consider where it is stored when it is not in use (i.e. in between venues). There may be cost attached to this.

With touring exhibitions it is not advisable to budget for any reselling value at the end of the exhibition run. Although the equipment may have some worth, second-hand AV equipment depreciates very quickly. The resale value will be further compounded by the length of the tour and the amount the equipment might get used.

Hiring equipment: There are also very good reasons why hiring equipment makes sense. Hired equipment, in most cases, comes with a greater level of service from the provider. This of course varies on the company, but could include: ongoing, maintenance and other costs, assisting with the selection of appropriate equipment for the task, telephone support in the day to day use, troubleshooting problems and fast replacement in the incidence of any equipment failures. Hiring equipment is not just about the cost of the equipment itself, it is about the total service that the hire company offers.

By its nature, a touring exhibition will visit different venues, and these may have very different physical characteristics. The same equipment is not always appropriate for all situations on a tour. This is particularly true for video projections. Hiring the equipment will enable you to tailor the exhibition and make the most of each venue.

Hiring equipment also makes good sense where the budget for an exhibition is split between multiple venues. This will enable each venue to make equipment selections in response and appropriate to their space and budget.

It is a good idea to use a hire company that specialises in the use of AV in gallery exhibitions. It is likely that their pricing will be structured to cater for the durations of gallery and museum exhibitions.

It’s worth noting that if you put the terms ‘AV’ and ‘exhibition hire’, or similar, into a search engine you will likely find AV companies that work in the commercial exhibition and trade show worlds. Although many of these companies are reputable and professional, it may be that they are not necessary familiar with the particular nuances and requirements of the gallery exhibition and museum environments.

A combination of hiring and purchasing: It is perfectly reasonable to organise a touring exhibition with a mixture of specifically purchased equipment and rented equipment, along with any suitable equipment that a venue or touring partner might already own. Sometimes specific items necessary for a particular artwork are just not available to hire and therefore must be purchased. However, there will need to be clarity over who is responsible for any fault or problems with the equipment.

Installation of the work
As recommended at the beginning of this chapter, if you have a reasonable amount of AV equipment in a touring exhibition it is highly advisable to speak to a professional AV consultant. To make the best of their assistance it is a good idea to get them involved as early as possible during the development of the project. They will be able to assist with the design of the exhibition and make specific recommendations about how you install the work. They should also consider how different venues will work and to develop solutions that will be appropriate and in keeping with the exhibition itself.

In addition to the physical differences between each space that a touring exhibition visits, you will also need to take into account the technical resources that are local to each venue, as these can vary widely. From those run by a skeleton crew with minimal technical space, otherwise reliant upon external and freelance support brought in as and when needed, to those with a large in-house number of employees, who have access to fully fledged workshops and other facilities.

There are a number of installation companies that specialise in AV production within galleries and museums; consult the Museums Association ‘Find a Supplier’ online resource for details: www.museumsassociation.org/find-a-supplier

In most cases, all AV equipment will need to be installed from scratch at each venue and then demounted, and packed at the end of the exhibition. With some exhibition designs that involves exhibition furniture designed to hold AV equipment; it can be possible to permanently fix some items and cables in place. This needs to be done with special care and consideration and is only suitable for certain items (these items will usually have fixing points in order to do this). This is never appropriate for projectors or screens.

AV rack mount trolleys can also be used, although they are only appropriate for some set-ups. These are designed to hold specific equipment that has been made to fit the standard rack mount size. They can be used whilst the equipment is in use and during transportation. However, the off-the-shelf sizes are more appropriate for audio equipment (rack mounts are used extensively in live and studio audio set-ups). They also have limited use in exhibition environments because they take up space as a thing in themselves, often more than is ideal. Discrete pieces of equipment on the other hand have greater flexibility about where they can be located.

There are a number of options when it comes to packing and transporting AV equipment. The simple and most economical way is to save the original packaging of the item and reuse it each time. In situations like live concerts this would be completely inappropriate and the equipment would probably get damaged very quickly. In gallery and museum environments though, there is a different standard of object handling and transportation. Most people involved in exhibition production and logistics should be able to handle both delicate and valuable objects. The original packaging for the AV equipment is designed and considered suitable by the manufacturer in order to protect the equipment. This only works in situations where the boxes can be maintained in good working condition.

If the equipment is to be transported by aeroplane or large transportation anywhere, or handled by a non-art/museum courier or any other unknown party at any point, then it will be necessary to fabricate some more serious protective packing. Wooden transport crates built to hold the equipment in addition to its original packaging are one option. Alternatively, bespoke flight cases can be constructed by specialist suppliers to hold most pieces of equipment in any way desired.

Whichever packing solution is used it is always worth remembering that you will need space to store empty boxes and crates. This will also be the case for hired equipment.

Daily switching on and off: However seemingly simple or complex an exhibition with AV equipment might be, during the planning stages it is important to consider who will be turning it on and off every day.

Some larger venues and museums have integrated and networked systems, that can control and monitor equipment and even centralise all playback. These set-ups require specialised and trained staff to run them. If they go wrong, they tend to need even more specialised people to fix them. In the right situation, these kinds of set-ups can be great if you have the resources and infrastructure to back them up.

A touring exhibition has a changing infrastructure, so these sort of centralised systems are rarely appropriate. It is more advisable to keep things as simple as possible. The truth is, with a number of venues in consideration, it will be very difficult to plan and account for the skill level of each individual who will have to turn the exhibition on or off. More often this routine task is the job of invigilators or security staff, but at any point it could end up being any member of an exhibitions team.

Avoiding problems before they start: A very simple suggestion – unless you have no alternative, or there is another particular reason, is to avoid buying equipment that is too cheap. This is particularly when the price difference of the product is wildly dissimilar to that of the market leading brands or professional standards. The truism ‘to good to be true’ will almost always certainly apply here.

Professional media players are a good example. Professional media players are designed for huge amount of playback, often full 24/7 running times. Cheaper consumer media players, on the other hand, are usually designed to watch movies at home on your TV.

Professional equipment is built for a greater level of use in terms of its design and fabrication; there is often a more rigorous quality control and testing over the parts that are used. It will be inherently designed to be more consistent in what they should do and to have less chance to fail or break down when doing it.

Regular maintenance

Daily/weekly maintenance: Once an exhibition is up and running, regular maintenance, at its basic level, involves routinely checking that all the equipment is running properly. This includes, for example, simply monitoring that videos are playing correctly. It also particularly important to check equipment, such as headphones, that can be easily damaged by visitors. This damage may not otherwise be picked up until a visitor informs a member of staff.

Projectors need filters to be kept clean and the area around projectors should be kept clean too. Lamp life will need to be monitored and lamps should be replaced when required. Bear in mind that every projector model has a different lamp life. Lamps should be changed before they reach the total possible hours. It is not a good idea to leave a projector to run until the lamp completely blows because occasionally the lamp can shatter. Additionally the brightness and colour will deteriorate too.

Most projectors have a warning when the lamp should be changed; with installation style projectors where there is a timer circuit on the lamp this can be taken as a true guide. In more economical models it can be possible to swap lamps without resetting the timer (either by accident or on purpose). If this happens the timer clock will be inaccurate. If this is done on purpose for some reason, or by accident and then realised, the time difference should be recorded and monitored as best as possible until the next lamp change. And ideally you should play it safe too and change the lamps early.

As LED, LED/Laser Hybrid and other types of projector become more common, filter and lamp changes will become less necessary. Until a projector is designed that doesn’t use airflow as a coolant, it will still be necessary to keep the filter areas clean (even self-cleaning models need the filter area vacuumed in locations that accumulate dust).

Touch screens will need to be cleaned in order to remove finger marks. This should be done with screen cleaning fluid and cloths. You may also find other non-touch screens accumulate finger marks as well, especially when displayed near touch screens. Visitors may experiment to find out if they do anything or not.

If any volume or other types of control are accessible by gallery visitors, these should be set back to their default position.

Maintenance in between venues: Ideally this should be done as part of the exhibition take down and packing process in order to give maximum time to investigate and remedy any problems found before the next venue.

All equipment should be visually inspected for any signs of physical damage or wear and tear – particularly trailing power leads, mains plugs, connectors and control knobs. Any damage should be further checked and repaired if necessary by an appropriate and competent person (particularly if an electrical fault is suspected, or there is any risk of fault).

All equipment that passes the above should be tested to check that it is working correctly. Projectors should be turned on and the lamp times checked and recorded. While the projector is on it is also worth making sure that the image looks right and that no visible aberrations have developed. Projector filters should be cleaned when the projector is off. If the exhibition requires each venue to start the projectors with new lamps these should also be changed. Anything abnormal should be further checked by an appropriate and competent person.

Careful packing and handling of the equipment will make sure no damage occurs in transit.

What to do when something goes wrong

Equipment spares: If you have purchased the equipment you will need to maintain a stock of consumables spares, this includes projector lamps and filters. It is always a better idea to have some in hand than to be caught short. This stock should be maintained throughout the duration of the show. If you wait to purchase replacements until you really need them you may encounter issues with stock and lead times and consequentially may end up with exhibits or displays not working for a period.

Although a good warranty should cover you for any failure (see below), if the budget allows and the amount of purchased equipment is sizeable enough, it is also a good idea to have a few spares of the actual equipment you are using. With some equipment, for example headphones, this is absolutely necessary.

If you have hired the equipment, the consumables and spares will be organised by arrangement between you and the hire company. This will vary depending on the situation, the equipment, their policies and the distance from where they are to the venue.

Equipment warranties: A good warranty is important, particularly for touring exhibitions that need to run or be available in the same form for a long period of time. You may be reliant on the warranty if something does go wrong.

When purchasing equipment, the need for a good warranty from the manufacturer is another reason it’s not necessarily a good idea to buy the apparently cheapest option. This is often one of the areas where budget brands make some of their savings, due to the additional cost of honouring (and producing equipment to the standard of) a good warranty. A small difference in price can make a much bigger difference if something goes wrong later

There are different types of warranty that manufacturers offer, each with different names that go some way to roughly explain what you will be getting.

A Return to Base warranty will mean you have to cover all the carriage costs to send it back to the manufacturer or their appointed service centre. Sometimes they won’t send a replacement unit out until the faulty one has been examined. This can take days, weeks or in the worst case longer.

A Swap Out warranty can include the fast replacement with some of the carriage costs covered, but there may be other limitations and conditions. For example some will require the faulty unit to be sent back at the same time, perhaps leaving you without a piece of work for a period of time until the re-installation can happen. In other cases the new equipment can be sent out quickly to solve the problem, with a more flexible arrangement as to when the faulty equipment is returned. Some manufacturers send out loan units to solve problems as quickly as possible but only temporarily, and this might be a different model to the actual unit you originally purchased.

Other warranties you may encounter include: Hot Swap, Prime Support, On Site, De-Install/Re-Install. It is very important to check what the actual terms of the warranty are, as singer Tom Waits says, ‘The large print giveth, and the small print taketh away’ ^x.

It is sometimes possible to arrange extended warranties through your AV supplier; this can be important where the life of a touring exhibition extends beyond 3 years (the most common length for a good standard projector warranty).

It is also possible with some AV suppliers and manufacturers to arrange special condition warranties, where the installation of piece of equipment is outside the standard terms of use. This is something that would need to be arranged through the AV specialist you purchase the equipment through.

If your tour travels internationally, you will need to consider how this relates to the conditions of your warranty. Some warranties can cover the equipment Europe-wide for example, but the terms of the warranty might change outside the UK. Very few of the large manufacturers have the infrastructure to implement true world-wide warranties.

Electrical equipment and PAT testing: The Electricity at Work Regulations 1989 requires that, ‘any electrical equipment that has the potential to cause injury is maintained in a safe condition’ ^xi. They do not state the method, frequency, who should conduct the maintenance or any other stipulation.

It is important to make sure that electrical equipment is safe to use; performing the regular formal visual checks, as recommended as part of the maintenance in between venues, is a good start. Additionally, anyone using any piece of electrical equipment, at any time, should look out for any signs of damage to that equipment. If anything is found or suspected it should be dealt with appropriately.

One way to perform a more detailed and thorough safety test is to have the equipment PAT tested. PAT testing is a redundant acronym short for Portable Appliance Testing; it is a series of electrical safety tests performed on movable equipment that is designed to run on 230volt mains power. These tests look specifically for electrical faults that could cause harm to the user or other people, or cause other sorts of damage.

At the time of writing, there is no legal requirement to perform PAT testing on equipment. Please see the Health and Safety Executive website for more information on this, and further details on your obligations under the Electricity at Work Regulations: www.hse.gov.uk/electricity/faq-portable-appliance-testing.htm

It is possible some insurance companies will insist on PAT testing and certainly some venues require all equipment to be tested as part of their house rules.

PAT testing should find some types of faults (if they’re there) that simple visual and other tests will not necessary pick up on, so it can be a good idea. Specialist companies offer the service; be aware there is usually a minimum charge up to certain number of items. PAT testing can be performed by any ‘competent person’ (see the HSE link again) with a PAT testing machine, However, unless brand new, these need to be regularly calibrated, which can in itself be expensive. It’s usually more cost effective to outsource this process.

Generally new equipment will not need to be tested, as it should have been tested as part of the manufacturing process. Again, insurance companies and venues may have different rules.

^x Tom Waits, Step Right Up,1977

^xi www.legislation.gov.uk/uksi/1989/635/contents/made

Last Updated: 23rd September 2015

Author: Alex Baker (2015)