Astana Hz. Sultan Mosque is one of the distinguished buildings in Astana, capital of Kazakhstan. It features an incredible worship area of over 60.000m2 to allow for 10.000 people to pray at the same time. The main hall has 1 main and 8 smaller cupolas, of which the main has a diameter of 28 metres and a height of 43 metres. All floors are covered with specially woven carpets, resulting in a fair absorption on the higher end. Most surfaces expect for the floors are covered with marbles and encaustic tiles from Iznik, Turkey. This unparalleled beauty has a price to pay acoustically, making the halls extremely reverberant especially on the lower end, thus making the electroacoustical design the ultimate challenge.
Complete structure was modelled in EASE4.3 and the exhaustive design process started, adding and removing lots of speakers so as to keep the intelligibility and sound pressure levels as high as possible, taking into consideration that even the simple breathing of 10.000 people is a significant noise. Since the construction schedule was very tight, time spent for design was of a big issue. After days of around the clock recalculations, Asimetrik (Turkish integrator company) engineers came up with the final design using RCF’s TT+ Touring and Theatre series speakers, which not only solved the reverberation issues but also the abundant amplifier power in these small-in-size cabinets provided the power needed for the over 120.000m3 halls. The state of the art TTL11A-H and TTL11A-B arrays were placed on two sides of the altar (mihrab) to provide for the main source with 6 delay lines of TT051A speakers in the main hall and another TTL11A-H and TTL11A-B array for the extended praying area with 2 more delay lines of TT051A speakers to fill in all the corners and also to maintain an even coverage of sound pressure and a flat response for the entire praying area.
The importance of discretion of sound systems in such venues with spectacular features cannot be overstated. Thus, all these speakers were customized to fit in the colours of marbles and tiles. Following the installation and completion of the venue, measurements proved the design to be right, with remarkable coherence to the computer model.