EXPO'98, the last Universal exhibition
of the Century took place in Lisbon, Portugal. This gigantic
exhibition was entirely devoted to sea themes. One of the exhibition
goals was to make known to the world Portugal's decisive pioneering
role in the Discoveries which led to the process of European overseas
expansion in the 15th and 16th centuries. EXPO'98 opened on 22
May and closed on 30 September 1998, with the participation
of more than 140 countries and an expected number of visitors
of 8.5 million. The exhibition took place on a 60 hectare
site around Olivais dock, an huge lake where 10 football pitches
would fit.
Apart from the regular pavilion exhibits
there was a lot of animation in the exhibition sidewalks and gardens.
16 outside stages boosted music performances constantly, ranging
from classic to rock and traditional music styles. These performances
of course were the object of on-site sound reinforcement, as
well as sometimes beinge broadcasted. The need has thus, since the
exhibition was sought, arise to process stage signals so as to
allow their accurate distribution to several destinations, while
preserving their quality.
To answer those requirements, Acutron,
on the basis of requirements set up by the responsible for the
electroacoustics Mr. Daniel Léon, created the DI8-24 and
DO-1616 microprocessor-controlled signal distributors. Those were
respectively a 8 by 3 input and an 16 by 16 output distributor.
They could be controlled by soft keys or by an external computer
via an RS-485 serial interface. The input distributor took the
stage signals, amplified those by a programmable gain factor
and splitted it through 3 different outputs offering at the same
times programmable and individual output ground lifts to help
alleviating potential ground problems. It is worth to mention
that equivalent input noise level of this device was in the order
of -130dBu, just to give the reader an idea of the stringent requirements
we had to meet.
Once a set-up for a show has been made,
it could be stored into one of the 14 internal EEPROM memories,
to be recalled instantly when the show is back again to the particular
stage.
DO-1616 was an output disrtributor with a built-in monitoring system alowing the on-stage sound quality evaluation. The device was equiped with programmable ground cuts.
Big events like the EXPO'98 often require
that new developments are made in a hurry. This one was not an
exception. The development of the DI-824 and the DO-1616 was made
from scratch in less than one month, hardware and software, in
the development department of Acutron. The production started
immediately allowing the first equipment to be delivered just
before exhibition start, within a less than 2 month record time.
Meanwhile, Acutron was in parallel delivering all the cabling
necessary to set up those 16 stages, which by itself was already
quite a gigantic job. To give the reader a faint idea of the work
scale, it will be enough to say that for example about 20Km of
microphone cable were processed.
The solution found by Acutron answered
to the original EXPO'98 requirements while introducing the programmability
and the availability of scenarios stored in the equipment. It
thus adapts closely to the lively character of the performances
that took place daily at the Lisbon exhibition. About 60 DI-824
and 30 DO-1616 were in use at the EXPO'98.
We profit to express our thanks to Mr.
Daniel Léon for the cooperation showed during all phases
of this work and our deepest appreciation to be associated with
such an ambitious and challenging project as EXPO'98 was.
