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Cité de l'Espace planetarium


Toulouse (31)


Bespoke architectural acoustic treatments, Bespoke sound system


Toulouse City Hall


280 pl.

Amount of work

€1,900,000 (excl. VAT)


Delivered in 2017

The Cité de l'Espace planetarium was renovated in 2017 to become one of the most efficient in the world. It hosted the World Planetarium Congress in 2019.


Tisseyre + Associés has 40 years of experience in room acoustics. 30 years ago, anticipating the shift to digital and 3D visualization, we developed tools and methods to optimize room acoustic solutions. Starting from the observation that the acoustics of a planetarium is particularly structuring for its architecture, we have developed a joint working methodology with the architect so that the acoustic solutions are integrated.


Bespoke architectural acoustic treatments

All the technical support necessary for the operation of planetariums (such as thermal equipment as well as projection and lighting equipment) must not produce a sound level curve exceeding 35 dB(A) or NR 27 to ensure sound quality. listening in the room. This is why we have implemented various acoustic treatments:

  • An acoustic absorber in the volume behind the screen: in spatial and basic sound system on all the walls in addition.
  • Treatment of armchairs using the acoustic quality of the fabric and its padding
  • Poorly absorbent floor covering.
  • Walls diffusing acoustics in the lower part of the crown and the rear wall to homogenize the acoustic field.

Tailor-made sound system

Thanks to our model center we visualize and control the sound image received by the listener. Thus, we are able to model in 3D the performance of sound systems in order to fully integrate them into the project architecture. The purpose of sound reinforcement for planetariums is twofold. On the one hand, the Lev acoustic envelope of each listener must be completely satisfied in order to match sound and visual image (at 180°) and to ensure optimal listening comfort. On the other hand, each listener must have a wide auditory sensation of the source in order to accentuate the impression of spatial grandeur (ASW). For this we have:

  • Equipped the sound perception zones with 4'' loudspeakers assembled in line array. This principle makes it possible, on the one hand, to avoid the loss of spatiality by the listener and, on the other hand, to homogenize the broadcast for each listener.
  • Procedure for adjustments to the directivity openings of the loudspeakers making it possible to increase the effective surface of diffusion and the envelopment (Lev).