Congress Centre with acoustics unique in Poland
In cooperation with experts from England, Krakow architects have designed special armchairs to offer comfort when listening to music.
This is to be a great attraction for music lovers. The architects designing the Congress Centre argue that the acoustics in its halls will be of top world quality. Finishing work is now going on.
‘In acoustic terms, solutions are being introduced which are not present in any facility in Poland. We will not find another hall of”vineyard” type in Poland with such a big capacity, adapted for both concerts and congresses,’ says the Krakow architect Krzysztof Ingarden who, together with Jacek Ewy, has designed the Congress Centre.
Consultations with British experts
The acoustic concepts in the Centre have been designed in cooperation with British specialists from Arup Acoustic Company. They are consulting, on an ongoing basis, the work on the Centre’s acoustics. Raf Orlowski, who has authored the acoustic design, comes to Krakow from Cambridge during the process of construction to control the completion of the acoustic elements of the interiors. When all the work has been finished, he will do the measurements in the hall and finalise its acoustic tuning.
In 2008, Arup Acoustic representatives measured the acoustic background at the location intended for the Centre. The results were used as input data to design a structure which would not transfer ambient sounds and vibrations into the inside of the halls.
Acoustic screens and an acoustic reflector
Work is now being done to install elements of relevance to the acoustics in the large auditorium hall with 1800 – 1950 seats (depending on the size of the stage) and the smaller hall for 600 people. Modern solutions are intended primarily to ensure full comfort while listening to symphonic concerts with large orchestras. In the main hall, the reverberation during concerts is to be 2.0 – 2.2 seconds. During conferences, such long reverberation would be uncomfortable. In some sectors of the hall, acoustic screens will therefore be installed which may be raised and lowered. Absorbing the sound, the screens shorten the time of reverberation. With their use, it can be reduced to about 1.5 – 1.8 seconds.
For the orchestra to hear themselves well, an acoustic reflector will be installed in the main hall – at the height of about 10 – 12 meters above the stage.
‘The big auditorium hall is about 20 meters high. An acoustic reflector reflects sounds just above the stage and directs them downwards and, to some extent, towards the audience. Consequently, early sound reverberations get back to the musicians for them to hear themselves better, and to the audience at the front of the stage,’ explains Krzysztof Ingarden.
Testing the armchairs
Acoustic tests are planned at the end of this month on the prototypes of armchairs which have been tailor-made for the concert hall of the Congress Centre by the Ingarden & Ewy design studio. The tests will be done in an acoustic laboratory in Italy, under the supervision of the author of the acoustic design, Raf Orlowski. The armchairs have been manufactured by the recognised Italian company Poltrona Frau, which equips the most excellent halls worldwide, such as the Oslo Opera or the Walt Disney Concert Hall.
‘The idea is to create the best conditions for the listener to listen to music. The armchairs must have perfect ergonomics, resistance, and acoustic characteristics as they contribute to the hall’s acoustic quality. They themselves are not clearly a source of sounds, but should not resound under the influence of vibrations,’ explains K. Ingarden.
It is not the shape of the armchairs itself that determines the acoustic characteristics but the type and quality of the materials (wood and upholstery) and their choice in the right proportions. ‘Hard and heavy materials reflect whilst soft ones absorb the sound. An acoustic engineer must balance everything and select the right type of chair to match the characteristics of the specific hall,’ emphasises the designing architect.
Centre for PLN 355 million
The Congress Centre’s opening is scheduled for October this year. ‘The work is being done in line with the timetable. Most construction work has been completed. We are at the initial stage of finishing the facility’ says Janina Pokrywa, Head of the Capital Projects Department, Krakow City Hall.
The project will cost approximately PLN 355 million. The Centre will have an auditorium hall (1950 seats), a theatre (600 seats), a smaller room (300 seats), a complex of conference rooms (300 seats), 32 meeting rooms (6–30 people), and 4,500 sq.m. of exhibition and banquet space.
Author: Piotr Tymczak, source: Dziennik Polski daily