Equipping For Stereo
“Although we launched stereo formally only a short time ago, we have been
doing stereo programmes here for quite a long time. We have been broadcasting
in stereo regularly since 1986, but not with an announced service, and all that
time we have been building up techniques and putting equipment in place. By
the time we announced a formal service last year we were in a position to say
right from the start that all your favourite programmes are in stereo. We were
saying 60% of the programming was in stereo, and in the evening hours it was
more than that. At Christmas time and some weekends we were getting up to 100%.
Because we didn’t want to say 'Look how nice this is’, and then
have people search the Radio Times to find the odd programme, we said right
from the start that we would do everything in stereo that we possibly can. And
when people say, 'What does this particular programme gain from being in
stereo and why are you doing it?’, we just say 'Well why not?’.
It’s like colour, we just do everything. If it doesn’t gain then it
doesn’t lose either. On some programmes surprisingly you do gain quite
a lot. One instance is the talking head type of show. If there’s a little
bit of air around the presenters and guests, a little bit of displacement from
side to side, it does help to pick up who’s speaking next. The obvious
shows of course are the music programmes which benefit enormously.
“We have been re-equipping and experimenting with microphones and other
equipment. In particular, like a lot of other people, we have been chasing manufacturers
to make single bodied MS stereo microphones. MS microphones generally work better
for us because they have got a single forward facing microphone so you are guaranteed
to get a mono compatible signal – the front of one microphone capsule is incomparably
better than the sides of two. We did a lot of playing around with the MS stereo
microphones that there were. None of them was particularly suitable for boom
work in the studio until our old friends at AKG came up with an MS version of
a microphone they already had. AKG in the UK are a very forward thinking organisation.
They could quite easily see that there was business to be done so they got Vienna
to make up an MS version of the C522 for us which they did very well. The good
thing about them is that they match our standard mono cardioid, the C460, very
well so we can mix them in combinations with no joins showing at all. We have
just bought our first ten or twelve and we are buying some more. At the same
time we have been re-equipping our booms with stereo cables. It’s these
kinds of things you tend to forget, but rigging two cables on a boom is a real
pain so we had to look for a stereo cable The Japanese Canare company make a
double quad cable and we are installing it on all our booms.
“All of this takes money and time. We have had to develop new specifications
for things like consoles with stereo channels, and we will pay more attention
to stereo imaging when we are doing our acoustics in future. We have also had
some interesting times with the distribution circuits. Dual channel Sound in
Syncs has given us some fun, the earliest versions of which were not at all
fun when there were vision disturbances. But we cracked the problems and now
the dual channel Sound in Syncs is now more robust than the old mono one and
even quite iffy vision links will carry it successfully.
“NICAM is brilliant. It produces a quality you couldn’t manage by
anything other than a digital system and you have to be listening under severe
test conditions to hear any kind of impairment at all to the signal, compared
with say a 16 bit linear system. Curiously now, because the developments in
digital technology have been so fast in the last few years, it looks rather
wasteful, there are much more efficient ways of compressing digital audio signals
which make much bigger bit rate reductions, albeit with more obvious artifacts.
There are virtually no audio signals that show up NICAM badly but most of the
others have a bete noir somewhere and something will show them up”.