Danish Parliament orates with d&b
As a model of what can be achieved with the correct proportions, the Danish Parliament with just one hundred and seventy nine Members of Parliament (including two each representing Greenland and the Faroe Islands) is superb. In terms of efficiency there is no better forum in Europe for developing, debating and enacting bills; the Danes bring a particular efficiency to the organs of Government of which even the Swiss would be proud. But like all European parliaments they are hampered by a contemporary affliction: in the age of the television interview, MPs have forgotten how to project. The demise of oratory means Parliamentary members now find they need a little assistance when it comes to addressing their fellow members in the debating chamber.
"This was strictly an audio installation," began Bjarne Rasmussen, system design specialist for Informationsteknik Scandinavia A/S. "There are some old LCD displays in the debating chamber for agenda and voting, but they're fifteen years old, some of the first ones ever to come on the market; so maybe we will be updating the displays soon." Informationsteknik is the leading conference and commercial presentation company in Denmark; they are routinely called upon to create discrete AV installation solutions for prominent clients, none more so than the seat of Government. "For audio we installed a complete microphone system," continued Rasmussen, "one at every seat; and a distributed audio system. The microphone system is in two parts; all the seats have our own brand DIS (Danish Interpretation System) microphones, and for the Speaker's position we have put DPA 4023. We believe this microphone to be one of the best for this position; it has the best off-axis response. Previously the Speaker had used a hyper-cardioid microphone, which produced significant problems for the listeners if he turned his head while talking."
Acoustically the debating chamber is not as easy as it first appears, although there is lots of wood panelling and carpet, the ceiling is very high, fourteen metres in fact, so reverberation was a problem. "Jordan Acoustic measured 3.5 seconds, so we made some consultations with the architects Henrik Levison, who were responsible for this heritage building, about applying some acoustic treatment." In the end rock-wool filled panels were applied; the architects contracting a specialist craftsmen to make the additions discrete and sympathetic to the existing interior design. "That brought reverb' down to a much more agreeable 1.4 seconds, which left us with the audio installation. This too was not as simple as it first appears; the original system installed was more for long throw, which this room isn't; it's barely twelve metres to the back of the debating chamber. Although the system has a good reputation for speech intelligibility, it is designed to operate in adverse listening environments, like railway stations, so the vocal bandwidth is quite narrow. The MPs often have to sit through quite long debates, so listening to a voice that we might characterise as sounding like a telephone, becomes tiring."
"Coverage was also very important, we needed to achieve a very uniform coverage across one hundred percent of the listening area, and that included the aisles and walkways around the chamber. Members of Parliament frequently move about during debates. We conducted many tests across a period of over one year, and we had a group of parliamentarians to give us feedback; these people are the law and they're not interested in measurements from test equipment, they gave us very direct thoughts on what was needed. To be able to hear just as clearly when moving about the chamber was one of them."
The physical shape of this semicircular debating area dictated that the 140° provided by the previous reinforcement system was not sufficient and that 180° was needed. "The design was simple enough, a centre cluster of three d&b audiotechnik Q7s provided main coverage, some E0s for the more awkward areas, and E3s for the balcony where former Members of Parliament and members of the Royal Family can watch and listen to proceedings. But again heritage considerations intervened. The architects were very sympathetic to the audio needs, but ultimately what would be the ideal position for the centre cluster was just not possible. However, the position we were given was practical; by zoning the left and right loudspeakers in one time delay, and the centre loudspeaker in another, I could get the listening correct. These loudspeakers have a good pink noise response, so it was easy to move about the room to every conceivable position and detect artefacts and correct phase overlap."
Despite the inevitable frustrations in dealing with a significant national building, and the sensitivities of conservation, there were upsides to this project, as Rasmussen revealed. "We were very lucky on the physical installation; the Danish Parliament has convenient breaks during the summer period so this was nothing like the pressured installations we normally do in the corporate sector. The results have proved to be very good, the system provides a very natural sound and everyone is pleased with the result."