How will these tests influence the auditorium’s geometry?

B.M.: It will mostly involve adjusting the angles of certain reflective surfaces, like the reflector clouds or what we call the canopy, to ensure sound return for the musicians.

FACT SHEET Auditorium acoustics

The main auditorium is truly the heart of the project. It was designed to “envelop” listeners with a new, clear, full and intimate sound. Echoing the architecture, whose elements seem to float in space, a concert at the Philharmonie will invite listeners to immerse themselves in music and slip into a moment of suspended time.

A 21st century auditorium

Architecturally, the auditorium is a cross between two classic auditorium styles: the “vineyard” model and the “shoebox” model. This new concept takes the best from both models: the first favours intimacy and creates a new rapport with the stage by wrapping the audience around the musicians; the second sets spectators on several balconies, allowing a reduction in the width of the hall, and a multiplication of early lateral sound reflection, promoting sound clarity.

The result is a unique architecture, a harmonious composition of acoustics, scenography and architecture, characterised by:

a rear acoustic space, obtained by detaching the balconies from the outer walls, that promotes late sound reflections

a maximum distance between spectators and stage of 32 metres

The "Philharmonie sound" - fullness / clarity / intimacy

Clarity of sound is created by all of the reflective surfaces that are “projected” throughout the acoustic shell. The balcony fronts and “ribbon” design of the walls behind the audience, as well as the reflectors located under the ceiling, were constantly remodelled as studies progressed. The goal was to create the early sound reflections, preferably lateral, that would guarantee the best possible presence of sound sources, precise sound quality and excellent sound diffusion for each and every audience member. The end result is:

remarkable sound quality for the musicians on stage;

efficient "early sound reflections";

a homogeneous listening experience over the entire seating area

an average EDT ("Early Decay Time" = measure for perceived reverberance) of 2 seconds;

an average reverberation time ("RT" = measure linked to the hall’s physical attributes) of 2.3 seconds.

Acoustic flexibility

Stage walls with variable absorption

Sound absorbing mobile acoustic curtains

Adjustable canopy height (9 to 15 metres)

Models

Harold Marshall, the hall’s acoustician, and Yasuhisa Toyota, acoustic consultant, conducted acoustic tests on both computer-generated models and physical models:

adjustment and verification of the auditorium’s acoustic qualities by creating 3D models of the building (using Catt-Acoustic and Odeon software)

acoustic measurements and tests using the impulse response method (in which a quick sound is transmitted and the response analysed) and the optical method (geometrical verification by laser calculation) in a 1/10th scale model, hermetically sealed under nitrogen.

FACT SHEET Building acoustics

The design and construction process was driven by the determination to meet standards of acoustical excellence.

Exterior soundproofing

The background noise criteria for the main concert hall is NR10 and 15dBA; for rehearsal rooms, it is NR15 and 20 dBA.

The roof is set on anti-vibration spring mounts, which serve to block any structure-borne noise caused by activity on the walkable roof.

In terms of outside noise, the building is insulated against the area’s principle noise sources: traffic (from the ring road, boulevard Sérurier, Philharmonie parking garage, etc.); other concert halls on the site (the Zénith, Trabendo); and air traffic.

The junctions of flooring/glass façades and partitions/façades will be subject to special acoustic treatment to block the infiltration of exterior noise.

All noise-sensitive spaces (rehearsal rooms, studios, group practice rooms, etc.) that have glass façades will not open onto the outside in order to ensure maximum acoustic insulation.

Insulation between rooms

All of the elements that separate rooms (ie. workrooms for artists in residence, dressing-rooms, etc.), whether vertical or horizontal, present the following characteristics:

perfect airtightness at the junctions of walls and partitions as well as at the junctions of walls/partitions and ceiling/floor;

perfect airtightness around bulkhead connectors through careful caulking.

separation insulation between rooms

Anti-vibration insulation

The layout of the building’s various spaces and the need for acoustic insulation means that some spaces need to be structurally insulated from others. This is the case for the main concert hall and several rehearsal rooms. There are several ways to ensure insulation: either through the creation of a “box within a box” system, or through the creation of floating tiles or dry flooring, or else through the creation of structural discontinuity by using acoustic joints.

All vibrating and revolving equipment, such as the air treatment units located in plant rooms on levels -2 and +5, will also be separately insulated from the structure of the building, in order to limit the spread of structure-borne vibrations towards the building’s critical spaces.

Interior acoustic treatment

Rehearsal rooms will be treated acoustically, in particular through the use of grooved wood panels to ensure adequate reverberation.

Through the use of mobile acoustic panels and sound-absorbing curtains, acoustics will be variable according to activity - from large symphony orchestra rehearsals to chamber music recordings.

Acoustic treatment elements will be separately insulated to avoid the creation of phonic bridges: suspended ceilings on anti-vibration hangers, floating tiles, screeds and dry flooring, etc.

Date: 2015-12-24; view: 760