Masjid Misr

ProjectMasjid MisrLocationCairo, EgyptArchitectMT ArchitectsInstallerAudio TechnologySubmitted byHOLOPLOT

The brief for Misr Mosque was to deliver clear, natural sound with the highest possible level of audio intelligibility in an extremely reverberant space – while preserving and respecting the architectural integrity of the 10, 000sq m mosque.

The mosque presents a uniquely challenging acoustic environment. The main worship hall covers an impressive area with most of the surfaces exposed to sound made from highly reverberant marble. The building’s central dome is 60m high, and the interior worship space is broken up by a number of pillars, also made from marble. The mosque is currently the largest in Africa, able to hold over 12,000 worshipers.

The HOLOPLOT X1 Matrix Array achieved unmatched spoken word intelligibility throughout the mosque, with dramatically reduced hardware installation requirements compared to other suggested solutions.

By combining two landmark innovations in audio-line arrays and electronic beam steering – X1 offers full control of sound in both horizontal and vertical axes through a matrix of loudspeaker drivers. This allows for sound control with ultra-high precision over large distances in a way that optimises the listening experience for every member of the congregation while eliminating spillovers and unwanted reflections.

HOLOPLOT’s X1 Matrix Array introduces several brand-new concepts not typically attainable from any other audio technology. 3D Audio-Beamforming allows the creation of ‘sound corridors’, extending to 100m in length with minimal energy spillage, thanks to the combined horizontal and vertical control ability of the X1 arrays. To optimise intelligibility further, all areas not regarded as listening areas or areas that could cause reflections are designated as avoidance zones within the HOLOPLOT design software.

The system consists of two four by two X1 arrays situated on the far left and right-hand side of the building, creating coverage corridors that deliver clear audio without a drop in level for an area that’s 93m long and 18m wide respectively.

The frontal system consists of X1 arrays in three-by-one and two-by-one configurations, positioned on either side of the entrance, with the minbar (prayer pulpit) to the left. This part of the system covers the frontal congregation space. Tailored beams avoid the mihrab (a niche in the wall that indicates the direction of Mecca) and minbar providing high gain before feedback. The first wavefront always draws localization to the front wall, avoiding feedback and interference echoes.

Two X1 arrays in a two by two configuration fixed at the dome base target the audience area below. Despite exceptionally high mounting positions of 23m, the arrays are still able to achieve a high direct-reverberant ratio and speech intelligibility.

Combined with the targeted outputs of the other modules, 98% of all standing and kneeling positions in the mosque fell within STI of 0.5 and 0.72.

Despite this impressive coverage, The HOLOPLOT system consists of only nine arrays – with six arrays positioned on the front wall, two on the dome base and one concealed in the ceiling to cover the rear. This is a 70% reduction in speaker positions, compared to conventional (line array) sound system solutions.

In order to physically conceal the X1 modules, specially crafted metal screens and painted cloth were used that were acoustically transparent while ensuring the speakers are invisible to worshipers.

Central to HOLOPLOT’s unique approach is the ability to perfectly control and shape sound in acoustically complex environments, manoeuvring highly reflective spaces with unprecedented accuracy. In this instance, X1 handled an existing reverberation time of 6s, caused by both the marble interior and 60m high dome, managing to not excite the reverberant field – directing energy away from reflective surfaces and preventing the need for large amounts of acoustic treatment.

To maximise intelligibility, HOLOPLOT’s approach to this project was to divide the areas of the mosque into targeted and avoided areas for sound – with each targeted area being served by at least one speaker module. These targeted areas are the corridors, the front, the centre, and the back of the room.

All areas not regarded as listening areas or areas that could cause reflections are designated as avoidance zones within HOLOPLOT design software. Thanks to its sound control capabilities in both the horizontal as well as vertical axis, X1 has the unmatched ability to actively prevent undesired energy spillage onto any room boundary, including the side walls and pillars.

HOLOPLOT 3D Audio-Beamforming technology enables the precise steering of sound, allowing for sound to be contained within defined zones. This combination of target and avoidance zones inside the system design approach significantly improves speech intelligibility without the need to acoustically treat the space.

For example, for the corridors section, a couple of four-by-two X1 arrays were situated on the far left and right-hand side of the building to create coverage corridors, delivering clear audio without a drop in level for an area 93m long and 18m wide respectively.

This landmark project not only met but exceeded targets. It set a new standard for how sound systems in houses of worship will be in the future. HOLOPLOT technology was the key element that ensured the worship experience inside the mosque is as intended by the architect, by the acoustic consultant and other project stakeholders, delivering a beautiful worship experience without distractions.

HOLOPLOT’s 3D Audio-Beamsteering capabilities allow you to control sound in the vertical and the horizontal axes for unseen-before precision, making it a game-changing advancement in audio. It allows sound designers and acousticians to navigate challenging acoustic environments like never before. HOLOPLOT will continue to bring this paradigm shift in sound control to other installation market segments.

Emad Shenouda, Projects Director at Integrator Audio Technology: “I’m pleased to say that together with HOLOPLOT, we met the client’s brief of creating a fully integrated system that satisfies all stakeholders. The project was full of challenges, starting from the size of the mosque, the room acoustics and of course project deadlines. Thanks to X1’s ability to not only control sound in the vertical but also horizontal it achieves unbelievable intelligibility, thought impossible in a space clad in marble and featuring a huge dome at its centre. HOLOPLOT exceeded our expectations in both the quality of sound and in hiding the equipment in such a way that it blends in seamlessly with the interior.”