FEATURE
QUESTIONS AND ANSWERS
Q. How can I get stereo sound from my TV?
A. You can’t unless it’s a stereo, model
fitted with a NICAM decoder, but that doesn’t mean you have to rush out and buy
a new television. A lot of VCRs have stereo sound decoders these days, which
will enable you to watch and record stereo TV programmes, and if you’ve got a
stereo satellite receiver, you can record satellite channels in stereo as well.
Q. NICAM, what’s that?
NICAM or Near Instantaneously Companded Audio
Multiplexing is a digital stereo transmission system developed in the 1980’s
and used by the BBC and ITV, it’s now available to around 95% of the UK
population. Sound quality is very good, almost as good as CD, and most TV programmes
have stereo soundtracks these days; even the one’s that don’t sound better in
NICAM. The satellite channels use a different stereo system, called Wegner
Panda 1, it’s not quite as pin-sharp as NICAM but it still sounds a whole lot
better than boring old mono.
Q. But how do I hear stereo sound, do stereo
VCRs come with speakers?
A.
No, they have stereo outputs and quite a few of them have headphone sockets as
well, which would be the simplest and cheapest way to hear the stereo sound,
but that’s not much use for family viewing. There are two alternatives, most
people connect the stereo output from their VCR to their stereo system. If you
haven’t got a hi-fi, or it’s not convenient you could get a pair of ‘active’ loudspeakers
which have their own internal
amplifiers, these cost around £50.
Q. What do I need to connect a stereo VCR to
my hi-fi?
A. Normally all you need is a stereo
phono-to-phono lead -- they only cost a couple of pounds -- it links the stereo line output sockets on
the back of the VCR to the ‘aux’ input on the hi-fi’s stereo amplifier. You
will also need to move the loudspeakers, so they’re either side of the TV
screen, otherwise the sound will appear displaced. Not all stereo VCRs have
line outputs though, in which case you will need a SCART to-phono lead, they’re
available from most audio and video dealers for around £10.
Q. Which is best, a stereo TV or connecting a
stereo VCR to my hi-fi?
A. NICAM TVs are definitely the easiest way
to get stereo television sound but the sound quality, especially on the cheaper
set’s, or those with smaller screens (21-inches or less) isn’t always very good. There are two problems;
firstly most TVs have quite small speakers, and set designers don’t like large
grilles on the front, so more often than not the sound is heard through narrow
slits down the edges of the screen. Stereo TVs with speakers on the side,
preferably in detachable pods, sound a little better and a few have extra
low-frequency speakers of ‘sub-woofers’ built into the back but they’re still
no substitute for separate speakers. In general you will get much a better
sound, with a more realistic stereo image using hi-fi speakers, moreover,
having the NICAM decoder inside the VCR means you can easily record programmes
in stereo. It is possible to record stereo programmes from some NICAM TVs, but
there’s little point in that, unless you’re stuck with an older pre-NICAM
stereo VCR.
Q. How about surround sound, is that possible
on a stereo TV or VCR?
A. There’s two types of surround sound at the
moment. Some stereo TVs have a facility to create a spatial effect, usually
called ‘pseudo surround’ from any source, however, this is most often used to
liven up mono material. Proper surround sound, though, uses the Dolby Stereo
system, this was originally designed as a multi-channel surround system for cinemas
in the mid 1970’s, with extra sound channels hidden away inside movie stereo
soundtracks. The surround sound signals are carried over when the film is
transferred to tape or laserdisc, or shown on TV (terrestrial and satellite)
channels with stereo sound. More recently a number of TV programmes have been
made with Dolby Surround soundtracks. The signals can be unscrambled using a Dolby
decoder, nowadays most are ‘Pro-Logic’ types which provide right and left stereo
channels, a centre-front channels for dialogue, and a rear effects channel, (normally
heard through a pair of speakers placed behind the viewing position).
Q. How do I go about getting a Dolby Surround
decoder?
Dolby Pro-Logic decoders can be brought separately
and integrated in with a stereo VCR and hi-fi system, prices start at around
£150; you will usually require an extra set of speakers, two for the rear
channels and one for the centre channel, so reckon on spending at other £100 or
so. Alternatively you could get one of the latest Surround Sound TVs. These
have built-in Pro-Logic decoders and they come with all the necessary speakers
and cables; the cheapest ones cost around £650. However, the best solution is
to upgrade your present hi-fi with an Pro-Logic AV amplifier, (£250 plus) or
start from scratch with a complete AV system, designed from the ground up for
home cinema use. These cost from around £750 and in general provide the best
sound; most of them come with a full surround sound speaker package as well.
Moreover they’re fully integrated and everything can be controlled form just
one remote handset.
Q. I’ve also heard about something called
THX, what’s that?
A. TXH is Dolby Surround with knobs on! It’s
actually a very precise specification drawn up by Lucasfilm, that dictates
precisely how the speakers, amplifiers and decoder work and are configured,
giving a far more accurate representation of the original cinema sound.
Needless to say it’s also very expensive, several thousand pounds for a basic
system, but it’s getting cheaper. However, for the moment at least normal Dolby
Surround is more than adequate for most people and it can add a exciting new
dimension to almost any movie, especially action blockbusters!
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Ó R. Maybury 1994 1810
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