With a capacity of up to 15,000, the Sulim Kadyrov Mosque opened in the Chechen Republic village of Oyskhara with a compliment of 70-plus RCF loudspeakers carried out by Master Sound with the assistance of the Moscow-based RCF distributor, Aris.
The mosque’s grand opening took place to coincide on the 69th anniversary of the birth of the first President of the Chechen Republic, Akhmat-Khadzhi Kadyrov, with the head of the Chechen Republic, Ramzan Kadyrov, attending.
The sound system covers the entire extent of the prayer halls – the main prayer hall and two halls on the basement level – providing optimal intelligibility.
Taking into account the lower and upper balconies, volume of the hall is about 14,000m3, surface area totalling 6,360m2. The requirements for the installation were determined using AFMG Ease computer modelling software. As there are no Russian intelligibility, Aris engineers turned to scientific publications and the Research Institute of Building Physics laboratory (RAASN) for reference.
According to these studies, taking into account the volume of the main prayer hall, the optimum reverberation time for RT60 in the 500Hz-1kHz frequency range should be from 1.9s to 2.2s.
‘Taking into account the extremely high resonance of prayer halls and the lack of a meaningful reduction using acoustic absorbers, we focused on intelligibility parameters,’ says Aris Head of Sales, Alexandr Shamray. ‘To achieve good intelligibility, the Speech Transmission Index (STI) must be around 0.60 or more. Relying solely on controlled directivity and quality of the sound system we worked on reaching 0.50-0.55 (or higher).
‘Focusing on the 250Hz, 500Hz and 1kHz frequency bands, we simulate the results using RCF digitally steerable columns – VSA 1250 II and RCF VSA 2050 II – placing the loudspeakers, where possible, with maximum coverage of 10m. The peculiarity of the proposed sound columns is the possibility of adjusting vertical angle and aperture, taking into account the placement of the listeners and the height of the placement of the speakers themselves while maintaining their vertical position.
‘In addition, these columns have a fairly narrow vertical radiation pattern, which increases the beam of direct sound into the area and reduces the amount of unwanted reflections. This approach is extremely important for increasing speech intelligibility in rooms with high reverberation.’
Four RCF VSA 1250 II speakers are suspended on the front wall near the mihrab and under the gallery at a height of 2m. Two further VSA 2050 II speakers are suspended on a pair of supporting columns of the dome closest to the mihrab, also at a height of 2m. An additional pair of VSA 1250 II suspended on supporting columns farthest from the mihrab provide delays. Ten L 2406T sound columns are used as sound systems for the balcony, placed on the front wall and on the column of the balcony, with 44 PL 8X ceiling loudspeakers on both prayer halls the basement level.
The tradition of inviting people to pray at the mosque has existed among Muslims for 14 centuries. Latterly is has become necessary to amplify the voice of the muezzin can overcome the noise of a modern city. To this end, each minaret is equipped with four weatherproof RCF HD 410T and HD 6045EN horn-type speakers. They are directed to all cardinal directions and used for the daily calls to prayer (adhān and ṣalāt). The HD range speakers are designed for long-throw vocal applications without loss of intelligibility and with low distortion.
More: www.rcf.it
