Improvement
to the VA system for the Louvre was set in motion because
of an art robbery that took place during opening hours. Police
were forced to close the museum and use the VA system to ask
all visitors to leave, the intention being to either catch
the thieves at the exits or find the art-work back in one of
the exhibition areas. Due to the poor intelligibility of the
original sound system a panic broke out leading to several
people being injured.
After this incident, the Louvre started its search for a sound
system that would be able to cope with the highly reverberant
environment. After testing a wide range of systems the louvre
asked Duran audio to set up a demo of their Intellivox system.
Hans Nijssen of Duran Audio and Acoustic Consultant Cees Mulder
carried out the tests. It was immediately clear to Mr. Puibarreau,
head of the technical department of the Louvre, that these
loudspeakers were completely different from all equipment that
had been tested before. In this first session the correct positioning
of the columns for the central area was determined. Four options
were discussed, two were tested:
1) four columns around the central pillar of the Pyramid
2) one column on either side of the escalators opposite to
the information desk
3) a column on two of the four giant pillars opposite from
the information desk
4) two columns on one of the four pillars
 Option
one and two were rejected by the Louvre for aesthetical reasons.
After a quick comparison between a one column and a two columns
setup several conclusions could be drawn:
• Although the coverage was wider with two columns active, intelligibility
within the covered area was better when shooting from only one position.
• Testing with only one Intellivox 2c, intelligibility was perceived
as ‘good’ up to a distance of approx. 30m and deteriorated slowly
after that.
• The ceiling under the upper entrance (Pic.1) had
a dampening effect on the reverberation in the area below it and thus intelligibility
increased in this area.
• Even behind the main escalators, intelligibility was sufficient
although the column was not visible from that position. This was probably because
of a strong reflection on the hard stone wall behind the stairs (‘lucky
bowling effect’).
• The corridors towards Sully and Carrousel could not be covered
from the central area.
After testing the area under the pyra-mid, a quick setup was
done with only one 2c (now know as the DC 280) in the central
area and the other one lying on the floor (the museum was closed)
in the corridor towards Carrousel. The Intellivox delay option
was used to time align the reproduced signal and it was established
that a smooth transition from the main area into the corridor
was possible using a horizontally installed column. Reverberation (5.6
sec @ 1 kHz near the information desk) and STI measurements (0.52 < STI < 0.66
from the 2c’s towards information desk) were made
in several series using MLLSA.
Ambient noise levels were measured both on opening hours (Leq
of 68.9 dBA) and during closing time (Leq of 63 dBA).
 Second demo
The first demo convinced the Louvre that this was the technique
to solve the problem. A second test however was considered
necessary, involving all Louvre personnel. The general director
of the Louvre, the head of security, the technical depa tment,
the fire brigade, PR staff, information desk employees and
custodians were to judge the system during opening hours
of the museum. For the second demo the Intellivox columns
were mounted almost exactly in the same way as they would
be in the final installation, in order to bring the test
conditions as close to the normal operating conditions as
possible. The test was held on April 21, 1999.
Based on the measurements and the experience
of the first demo, two columns with greater acoustical length
the Intellivox-4c (DC 430) were temporary installed on one
pillar in the central area and two Intellivox-2b (DC 180) were
mounted on the back of that same pillar to cover the mezzanine (Pic.
2). For both
the concourse towards Carrousel and towards Sully a symmetrical
column type was used to prevent side lobes from reflecting
on the entrance constructions of the shops lying along the
concourse. After extensive testing with both live and recorded
spoken word, it was finally decided that the results were excellent
and that this was definitely the next sound system to be installed
in the Louvre.
The long and winding road
Even after a successful demo it may still be a long process
to a final install. Because of the fact that the sound system
is part of the fire alarm system, interfacing had to be designed
carefully. Since every loudspeaker in the Intellivox series
is network capable and can provide all relevant status and
control information over the net, it was decided that a network
server had to be included in the system design.
A dedicated software package called AXYS Audionet Navigator
(Pic. 3) was designed to run on the server
for permanent surveillance of DSP status, amplifier status,
ambient temperature, amplifier temperature, power supply and
ambient noise microphone. Status information is displayed on
a monitor and all relevant events are stored in a logfile.
Files can be printed or emailed if needed. To provide proper
inter facing with the existing (automatic) fire detection system
an I/O interface is integrated with lines that enable loudspeakers
in a specific zone where the fire detection is triggered. Voice
Alarm is then given by the Philips SSR-2 (solid state reproducer)
an automatic announcement system. Manual override can be per
formed from call stations connected to a Philips SM-30 system.
The SM-30 serves  as
a pre-amplifier, is handling priority routing and interfaces
with the I/O board of the Audio-net Server to activate the
loudspeakers in specific zones. In order to facilitate usage
on special occasions, a wireless handheld microphone was also
included in the design. In this way the system can also be
used for intelligible official speeches etc.
Obstacles
Another hurdle that had to be taken was civil engineering.
French installer GTIE had to drill a large hole for the cabling
through one of the massive pillars. Marble tiles had to be
removed and for a second hole through a huge wall a passage
of more then 1.5 m deep had to be drilled. All this had to
be approved by the architect, which also took quite some
time. The mountingof the columns with standard hinges was
not acceptable, and the architect came up with a metal cover
to keep the hinges out of sight. Also the color of the columns
 was carefully matched according to their mounting positions
in the building. The installation point at the start of the
Sully corridor which was initially chosen for obvious acoustical
reasons - was rejected for aesthetical reasons, therefore
the Intellivox 5sym was eventually installed at the end of
the more then 60m long corridor facing towards the central
area. As it turned out during the commissioning, careful
tuning of the throw by adapting the volume made a smooth
transition possible from the corridor into the central area.
Finalization
The Intellivox loudspeakers were shipped August 2000, 15 months
after the second demo. Still it took another six months before
the systems could shine (pic. 4). Final commissioning was
on February 19-21st 2001. All the waiting turned out to be
worth while. Results were measured by Cees Mulder again and
they were even better then expected. Nothing could be more
rewarding then the expression on the face of Mr. Puibarreau
of the Louvre using the wireless to speak for the first time
under ‘his pyramid’ over the new VA system, discovering
that every single word was easily understood in every corner
of the area.
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