Articles and whitepapers

Video and Displays for Superyachts (22/10/2003)

By Coastal Acoustics

There are a variety of source formats, distribution methods and display devices that can be used to reproduce video and TV in a home or superyacht environment. Each has a different effect on the resulting picture quality, ease of distribution, size, weight, heat output and cost. Achieving optimum results in critical viewing areas requires a careful choice of components to achieve professional colour rendition, contrast, white and black levels, and to limit interference. Non-critical areas do not duplicate the same criteria, and usually size and aesthetics are of more importance. The sections below describe in more detail the alternatives presently available for video and displays.

onboard theatre

Source Equipment

Satellite, DVD and VCRs are the main video sources used onboard most yachts. Satellite signals are usually decoded centrally and piped to all necessary areas, while DVD and VCR sources are placed locally or in a jukebox archive system. Due to their international nature, superyachts encounter a range of complications not usually associated with home video systems. Some of these issues include:

Satellite receivers
Satellite receivers must be included for all world zones in which the vessel may travel, and the control interfaces incorporated for all of these.

Different standards
Video sources employ a range of different standards around the globe, the major formats being NTSC, PAL and SECAM. These must be understood and accommodated for in every region that the vessel may travel.

DVDs (Digital Versatile Discs)
DVDs incorporate region coding which is applied to the disc during manufacture, so that movie distribution companies can control the release of new movies into different territories. DVD players must be 'chipped' to enable multi-region playback of all DVDs. The region codes are designated as shown in Table 1.

Table 1 - designated region codes

Region 1	US, Canada, US territories
Region 2	Japan, Europe, South Africa, and Middle East (including Egypt)
Region 3	Southeast Asia and East Asia (including Hong Kong)
Region 4	Australia, New Zealand, Pacific Islands, Central America, Mexico, South America, and the Caribbean
Region 5	Eastern Europe (former Soviet Union), Indian subcontinent, Africa, North Korea, and Mongolia

As always, local sources should be integrated into the room decor and not contrast with it. DVDs, VCRs, control and local receiving equipment are usually fitted into custom-made furniture, in professional sliding rack systems. These hold source gear safely in all weather conditions, and provide easy maintenance access, with all wiring professionally loomed, labelled and documented.

Video Formats

As discussed above, on an internationally-roaming vessel, careful consideration must be given to video signal formats and their transfer from central or local sources. There are a number of popular standards used for receiving and distributing video signals, for example PAL in the UK, SECAM in parts of Europe, NTSC in the US, and various derivatives elsewhere. The generic name for these format standards is 'composite video,' and for every area a superyacht intends to travel and playback local source, these should be anticipated.

Composite video (CV)
CV is widely used for transmission and distribution because it combines all the necessary components of the video source into a single signal. Piping CV around a ship is relatively simple as the connections are easily split and 'daisy-chained.' The down side is a loss in picture quality inherent in the format, which becomes more and more apparent as your screen size increases.

The other widely used video formats are RGB, component video and Y/C (commonly know as S-Video) and these can be summed up as follows:

RGB
RGB video is the format recorded onto a DVD, and it would therefore follow that applying this signal directly to your plasma or projector would offer the least signal degradation and best possible picture quality.

Component video
Component video is a mathematical derivative of RGB, offering extremely high quality in a format which is more robust and easier to transmit than the original RGB. This format is widely used with DVD players, projectors and plasma displays.

Y/C (S-Video)
Y/C is a further derivative of the component video format where the 'Y' part of the signal (black and white information), is sent separately to the 'C' part of the signal (the colour difference information). Although a derivative, the degradation caused by combining the colour information is fairly minor and on the whole, this format offers very high quality viewing.

For non-critical viewing, composite video from DVD players and satellite receivers can be modulated and combined into a single signal, similar to that received from a terrestrial television aerial. This signal would then be amplified and fed around the ship, and is sufficient for non-critical viewing or for smaller screens.

In the more critical areas using plasma/LCD screens or projection systems, it would be prudent to use either RGB or S-Video signals. As these are components of the picture signal, and also contain synchronisation information for the display, it is very important to maintain consistency between the individual signals. Although there are recommended maximums for cable lengths, other factors such as cable quality must also be considered. There are devices available which allow the distribution and amplification of both RGB and S-Video, and careful planning is required to avoid interference, noise and colour problems. Many installers do not consider these issues, and consequently viewing pleasure can be eroded by low-grade picture quality.

Display Types

CRT Televisions
Cathode ray tube TVs generate an image by bombarding phosphors with electrons from an electron gun. The excited phosphors glow and emanate red, green and blue light, which forms a picture. While CRT TVs have excellent colour accuracy, a deep black colour, and are cost effective, they suffer from a number of problems. Reflections, narrow viewing angles, and distortions nearer the edge of the picture all result from the curvature of the glass screen. However the primary disadvantage of using a conventional TV onboard a superyacht is its size and weight.

CRT television

With the recent introduction of plasma and LCD screens has come a whole new era of design possibilities. With screens measuring up to several feet across, and only a few inches thick, in addition to hanging on walls, potential now exists for elegantly concealing display devices within furniture and ceilings.

Plasma screens
Plasma displays use gas excited by an electric pulse to give off ultraviolet rays, which in turn excite red, green and blue phosphors, that light up to create an image. Screens are available in a range of sizes from about 30 to over 60 inches across, and unlike conventional CRTs, they measure only a few inches thick.

Easily mountable on hoists, drops and swivel systems, they can be discreetly hidden using a variety of techniques, or simply hung on the wall. Being perfectly flat, the screens can be viewed at nearly any forward angle, and suffer from minimal reflections. As far as quality is concerned, if you look closely at early plasma screens the image appears pixelated in a similar way to JPEG image compression on websites. The technology has improved vastly since these times, and now it is hard to tell the difference in 'crispness' between a plasma screen and a conventional CRT TV watched from a normal viewing position.

Loudspeakers and UHF tuners are rarely integrated into the units, and provision usually has to be made using external devices. This can be advantageous as enhanced stereo imaging and low-frequency reproduction can be achieved using larger remote loudspeakers, and higher quality tuners can be stowed into hidden rack space.

42-inch plasma hung on wall with loudspeakers concealed behind acoustically transparent wall covering

Used appropriately, plasma screens make exceptionally good medium-to-large scale displays, although it should be noted that luminance and quality varies greatly between manufacturers.

Projection Systems
For large-scale cinema quality playback, the only option is a projector and screen system. There are a number of projector types available, including CRT, LCD, DLP and more recently, D-ILA, all of which vary in performance in terms of quality, luminance and cost implications.

Cathode Ray Tube (CRT) Projectors
CRT projectors work in a similar way to a CRT TV, but instead of projecting the image directly onto an internal glass screen, the picture is projected through three lenses, red, green and blue, and focused onto a reflective screen. The process produces an excellent colour balance and a deep black, but the devices are generally bulky, expensive, and complex to set up.

CRT projector

Liquid Crystal Displays (LCD) Projectors
LCD projectors work in a similar manner to LCD screens. A powerful light source is placed behind a liquid crystal matrix, and electrical impulses sent to the matrix to change the crystals' opacity. This blocks out the light in varying degrees and the resultant image is projected through a single lens onto a reflective screen to form a cohesive image. Whilst small, lightweight, easy to set up and inexpensive, LCDs generally have a lower resolution and a poor contrast ratio, i.e. black appears grey because the crystals do not block out all of the light source. When viewed close-up, they also tend to exhibit a 'screen door' look, where the individual pixels and the tiny gaps in between them can be seen.

DLP projector

Digital Light Processing (DLP) Projectors
DLP projectors use a vast array of microscopic mirrors that pivot on or off to reflect red, green and blue light, dependant on the incoming video signal. Around 500,000 mirrors, each only 16 microns square and representing 1 pixel, are contained on a small DMD microchip. The 'screen door' effect is largely overcome as the mirrors make up 90% of the projected image (aperture ratio) compared with only 70% covered by LCD projectors.

The mirrors, having only a digital on/off transition, create half-tone colours by vibrating their state up to 1000 times each second, and when combined with a powerful light source and projection lens system, offer 16.7 million colours at a much higher light output than LCD or CRT designs. They are available in 1, 2 or 3 chip formats, each representing a step up in quality and corresponding price, and for medium-to-large-scale private cinemas, offer an excellent-quality solution.

D-ILA Projectors
D-ILA projectors are a reasonably new technology which use a 0.9 inch diagonally-reflective CMOS chip developed by JVC. While it is a type of LCD, the chip's architecture is more advanced, and achieves a much higher aperture ratio of over 93%, superior contrast ratios and brightness, and overall a much smoother picture.

A ceiling cavity mounted projector and mirror system designed to minimise room impact

Projector screens
Projector screens play an important part of the equation, and vary in their reflective gain, and absorptive and acoustic properties. 'Acoustically transparent' screens allow for hidden loudspeaker placement behind, providing an elegant and professional audio solution. These screens are perforated, and care should be taken to avoid moiré patterns, a distortion where the projector scan lines interfere with the screen's cross-hatching. Screens and projectors, as with other display devices, can be incorporated into furniture, retract into ceilings or floor spaces, as well as auto-mask for wide-screen or standard-ratio formats.

This article appears courtesy of Coastal Acoustics. As well as private theatres, Coastal Acoustics has specified projection systems for numerous commercial-grade installation such as Pinewood Film Studios, the Sony Music Whitfield Street Studios and the Solid State Logic Oxford demonstration room.

www.coastalacoustics.co.uk