HOME ENTERTAINMENT 94

 BootLog.co.uk

HomeSoftwareArchiveTop TipsGlossaryOther Stuff

FEATURE

HINTS AND TIPS SPECIAL -- PART 1

GETTING STARTED

 

Dolby Pro Logic, SR-D, THX, digital surround ... It’s easy to get embroiled with home cinema technology, but back in the real world stereo TV sound will be most people’s first encounter with the audio-visual revolution. Television sound in the UK remained stubbornly monophonic up until five years ago. Before that the only stereo AV sound sources were pre-recorded video tapes and laser discs. Then in 1989 the BBC and ITV began broadcasting in stereo, they’ve since been joined by a clutch of stereo satellite channels. Stereo TVs and VCRs have become much more affordable, but there’s still a lot of confusion surrounding the subject, and far too much misleading hype.

 

Don’t be put off, the whole business is lot simpler that it appears, if it’s broken down into bite-sized chunks. For example, there are only four stereo AV sources to worry about: terrestrial TV, satellite TV, video tape and laser disc, (five if you count video games, but that’s another story...), and only two ways of listening to them: through a stereo TV or through a hi-fi, connected to a stereo VCR.

 

But where do you begin, once you’ve decided to go stereo? The logical starting point is terrestrial TV, after that everything else clicks into place. Both the BBC and ITV use a system called NICAM, where the stereo sound signal is transmitted on a slightly different frequency to the vision and mono sound signals, this reduces the chance of interference, and ensures compatibility with existing, mono equipment. NICAM decoders are built into stereo TVs and stereo VCRs, there used to be a few stand-alone NICAM tuner on the market but they’ve mostly disappeared now.

 

NICAM TV’s are the way to go if you want to keep things simple, there’s nothing more to buy, just plug it in and providing you’re not one of the unfortunate 5% who cannot receive stereo broadcasts -- check first! -- you’re in business. If you’ve got a stereo satellite receiver you can connect that to the TV’s audio input, so you can hear satellite channels in stereo as well.

 

There’s a couple of points to bear in mind with stereo TVs, though; the most obvious one is you cannot record TV programmes in stereo, unless of course you have a stereo VCR -- we’ll come to that in a moment . Secondly, some stereo TVs are not all they’re cracked up to be. Most of them have squitty little speakers stuck behind narrow slits down the sides of the screen. Not to put too fine a point on it, many stereo sets -- especially the cheaper ones -- sound pretty mediocre, it’s difficult to tell whether you’re listening to a stereo programme or not on some of them! A handful of sets, in particular those with side-mounted speakers, or in detachable pods, sound a little better, and a few -- very few -- have carefully designed speakers and extra low-frequency ‘sub-woofers’ drivers. They sound great, but in the main it’s fair to say that the sound quality on stereo TVs comes a poor second place to the cosmetics.

 

That brings us to stereo VCRs. Since the late 1980’s pretty well all VCRs with stereo hi-fi sound systems have had built-in NICAM decoders, which is the best place for them when you think about it. It means that you won’t have to buy a new TV if your present one still has some life left in it; in any case stereo VCRs are usually a lot cheaper than stereo TVs. You’ll be able to record TV programmes in stereo, and that includes the satellite channels; and don’t forget most pre-recorded movies on tape have stereo soundtracks. However, the best part is that  you will hear the stereo sound to its best advantage, by piping it through your stereo hi-fi system -- assuming you’ve got one of course... It doesn’t even have to be a top-notch system, even budget hi-fis will often do quite a good job  However, all that is easier said than done. In most homes the video and the hi-fi are rarely next to one another, or even in the same room, so this approach to stereo TV sound often entails a fair amount of upheaval, but it’s well worth the effort.

 

So how does it all work? A minimum system will normally comprise a TV, probably mono, preferably one with a largish screen (25-inches or above), a NICAM stereo VCR, the hi-fi system and speakers, and possibly a stereo satellite tuner. The first step is to get them all together in one place, including the speakers which should be placed either side of the TV screen. Most of the existing connections remain as they were; the feed from the TV aerial goes into the back of the video recorder, and the aerial lead from the VCR goes to the back of the TV. If there’s a satellite tuner in the system this can be ‘daisy-chained’ between the aerial downlead and the VCR.

 

Most VCRs have only one SCART socket, this should be used to connect it to the TV, for the best off-tape and off-air picture quality. This may mean you won’t be able to record satellite TV programmes in stereo, though if the VCR has a separate audio line-input -- and quite a few do -- you can connect it to the stereo output sockets on the satellite tuner, with a stereo phono-to-phono lead. The VCR’s stereo line-out sockets are connected to the auxiliary (aux.) input on the stereo amplifier. If the VCR doesn’t have a line input the stereo output from the satellite tuner should also be connected to the stereo amp, using a spare ‘tape’ or ‘CD’ input via a stereo phono-to-phono cable. Incidentally, you can use the same basic technique to improve the sound quality of a stereo TV; most of them have line-audio outputs which can be hooked up to the hi-fi system’s aux. input, just mute the TV sound and listen to it through the hi-fi speakers.

 

AV leads are not terribly expensive, a decent SCART-to-SCART cable costs about £8. There’s a few points to watch out for; make sure you get a ‘Type C’ (aka 9-pin) or ‘Type U’ (aka 21-pin) lead, which are configured for video and audio signals; (a Type U lead is necessary if you’re using a Super VHS video recorder with a TV that has an S-Video configured SCART). SCART leads are very widely available from most video and audio dealers, electrical shops and high-street chains. Most of them are 1.5 metres long, which is fine for most installations but if you need a longer one you will have to go to a specialist dealer. A growing number of SCART connectors have gold-plated contacts, they’re worth having because they won’t corrode and should maintain good electrical contact longer. Take all the nonsense about improving picture and or sound quality with a large pinch of salt, and don’t be fooled into paying a lot more for them. There are several good ones around for £10 or less. Stereo phono-to-phono leads are, or should be quite cheap, in fact one or two freebie leads are usually supplied with AV products. They cost a pound or two to buy, and again beware of overpriced gold-plated leads.

 

To sum up, unless you’re prepared to shell out on a top-end NICAM TV, (and you’ll still need a NICAM stereo VCR if you want to record TV programmes in stereo), the best course is to get a stereo VCR and connect it up to your hi-fi system. This is the most flexible approach, it’s cheaper -- NICAM VCRs start at under £300 -- it’s the first rung on the home cinema ladder and will give you the best sound.

 

BOXOUT 1

LIVING WITH STEREO SOUND

There’s more to stereo television sound than just having the sound coming from two speakers, instead of one. To get the full spatial effect it’s important to have a well-focused stereo image, and that may mean re-positioning the TV in the room, so that the speakers can be placed a foot or two either side of the screen. Don’t be afraid to experiment with various speaker locations, but don’t move them too far apart as the sound can become detached from the screen, which can be quite disconcerting. Some stereo amplifiers have switchable outputs for a second set of speakers, use them if you don’t want to devote the main stereo speakers to AV operations.

 

It may be necessary to move the furniture around, so that the ideal seating position is a comfortable distance from the screen and in the centre of the stereo sound-stage. Make sure other items of furniture don’t create unwanted reflections or absorb sound from one of the speakers.

 

Connecting the TV, VCR and hi-fi together means they will all have to be physically close together, it might be worth investing in a purpose-designed AV racking system, or ‘home entertainment’ console  -- available from your local furniture superstore --  to house all of the components, simplify wiring and reduce clutter. It will also make life easier when it comes to controlling the system. Multi-function remote controls can be a godsend, reducing the number of handsets to manageable proportions; several models on the market can control up to half a dozen different devices.

 

 

BOXOUT 2

WALK-THROUGH CAPTIONS

 

* The lead from the TV aerial goes to the aerial input or ‘RF in’ socket on the back of the VCR. Connect the aerial output from the VCR to the TVs aerial socket, using the lead supplied.

 

* For best picture quality the VCR should be connected to the TV via their respective SCART sockets, though this will not give you stereo sound, unless  you have a pre-NICAM stereo TV. Retain the aerial lead connection between the TV and VCR, this will enable you to use the TV as normal, it may also be necessary to use the TV’s own channels in order to receive teletext information as the data can be corrupted or stripped out when the signal passes through a VCR.

 

* The stereo line-audio output sockets on the back of the VCR are connected to the auxiliary input on the back of the hi-fi amplifier, using a stereo phono-to-phono lead. If the amplifier doesn’t have a spare ‘aux.’ input you could use either of the ones marked ‘tape’ or ‘CD’, but do not use the ‘phono’ input as this is configured for a completely different type of signal, and you could end up damaging the amplifier’s input circuitry.

 

* Most stereo satellite receivers have line-audio outputs as well, and these should be connected to the VCR’s line input, if it has one, or the amplifier in the same way as the VCR, though you may have to sacrifice one or more audio components. Alternatively, you could use a stereo audio switch box, they’re widely available for between £16 to £20 from most video and audio dealers. If the VCR has twin SCARTs, one of those could be used to connect it to the satellite box, this will also enable stereo recordings to be made from the satellite channels.

 

BOXOUT 3

A BRIEF HISTORY OF NICAM

NICAM evolved out of a digital audio transmission system -- called sound-in-synch or SIS -- developed by the BBC during the early 1970s, to distribute TV sound around the network. By the mid 1980’s BBC engineers had begun work on a digital stereo broadcasting system, based on sound-in-synch technology; tests carried out in 1986 proved the system worked and didn’t interfere with existing TV sets. In 1987 the specs were frozen, NICAM was born, and decoder chips were developed by Ferguson and Texas Instruments; test broadcasts began in earnest from the Crystal Palace transmitter in South London and Wenvoe in Wales, the latter was chosen for the surrounding rough terrain, which tested the signals durability.

 

Due to a lack of stereo material the public launch was a low key affair. Funding problems at the BBC prevented them from being first,  it was left to ITV companies in London and Yorkshire, and Channel 4 to officially begin NICAM transmissions in September 1989, initially with just an hour or two of programming each day. Today around half of all TV programmes have stereo soundtracks, and the service reaches around 95% of the population, the remaining 5% -- mostly in isolated rural areas served by small relay transmitters -- may have to wait until the turn of the century to get NICAM.

 

 

BOXOUT 4

GLOSSARY

 

AV

Audio-visual or Audio and Video; term used to describe items of home entertainment equipment or systems that operate with, integrate or process both picture and sound signals.

 

CO-AXIAL

Type of screened cable and connector used to carry very high or ultra high frequency (VHF/UHF) signals from an aerial to a TV, VCR or FM radio. Aka ‘Belling’ and RF connectors.

 

COMPOSITE VIDEO

Video signal containing brightness (luminance), colour (chrominance) and picture synchronisation information; see also S-Video.

 

 

HI-FI STEREO

Recording system used on stereo VHS video recorders. Aka DFM or depth frequency multiplexing.

 

NICAM

Near-Instantaneously Companded Audio Multiplexing; high quality digital sound transmission system developed by the BBC and used by the BBC and ITV companies to broadcast stereo TV sound in the UK. Also used in Scandinavia and New Zealand.

 

PAL

Phase Alternate Line; 625-line colour TV system used in the UK, throughout much of Europe, parts of Africa and the middle East, Australia and New Zealand.

 

PHONO

Simple screened push-fit connector system for carrying audio and video signals. Aka RCA and Cinch

 

SCART

Syndicat  des  Constructeurs  d'Appareils  Radio  Recepteurs et Televiseurs. 21-pin connector system used to convey video, audio control and data signals between AV components, widely used throughout EU. Aka Euroconnector and Peritel.

 

SR-D

Dolby Surround -- the next generation, providing up to six digitally encoded surround sound channels

 

S-VHS

Super VHS; sub-format of VHS, using the same style of cassette but capable of much improved picture quality.

 

S-VIDEO

Video signal broken down into its component parts -- to prevent interaction -- with the brightness and chrominance components carried separately. Used to convey signals between S-VHS (and Hi8) equipment

 

THX

Tomlinson Holman eXperiment -- surround sound system specification devised by Lucasfilm, and licensed to home cinema equipment manufacturers.

 

WEGNER PANDA 1

Stereo sound transmission and noise reduction system used on the majority of satellite TV channels

 

---end---

1994 1910

 

[Home][Software][Archive][Top Tips][Glossary][Other Stuff]


Copyright (c) 2005 Rick Maybury Ltd.

admin@rickmaybury.com