The New Concert Hall in Stavanger
Transcription
The New Concert Hall in Stavanger
Nytt konserthus i Stavanger The New Concert Hall in Stavanger Eckhard Kahle, Kahle Acoustics, [email protected] Henrik Möller, Akukon, [email protected] Tønnes A. Ognedal, Sinus, [email protected] Noise from outdoor sources • Ships are the major noise source • Vibrations taken care of by separated strucutres • Noise reduction depening on location Requirements and Solutions • Noise limit for Fartein Valen: 15 dBA • Administratively avoid most noisy boats – Boats Lw > 110 dBA to be placed elsewhere • Accept horns (Lw = 140 -160 dBA) – used mainly outside concert hours • Double sound insulating structure: – Two concrete walls – large cavity – vibr. isol. – Heavy roof, suspended ceiling with large cavity Sound insulation between halls • Structural split between building bodies – No common fundation – Air gaps prefered – Rockwool and elastic seals allowed in places • Additional 18 dB joint around each hall – Elastic rubber/steel connectors (dybel) – Rockwool and elastic seals in joints • Technical installations crossings minimized • Specifications made for acoustic and fire sealing Acoustic separation from the bottom: Checking strutures before and after concrete is filled Testing and repairing acoustic separation Controlled hammering pluss measurements of vibrations several times during the building process. Technical installations across acoustic split Example: elastic cable tray support Before the first test concerts with both halls: Closing several doors & Sealing leaks. A rock concerts in Zetlitz is not audible in Fartein Valen! LpAF,max < 15 dB ? LpAF,max = 105 – 110 dB Noise sources in Fartein Valen • Very strict requirement set for every source. • Example test of floor diffusors: Lw,A = 5 dB corresponds to Lp,A (1m) = - 3 dBA Aspiration smoke detectors • Enclosures required Spiral stairs above ceiling stabilization required Noise towards neighbours • Double doors in facade: Foyer: Reverberation times Concert Hall Brief and main design goals: • 1500-seat classical Concert Hall • Shoebox shape • Optimized for moderate-size symphony orchestra • Large-scale symphonic works are exceptional but need to be possible with good acoustic conditions • Recitals, chamber music and chamber orchestras are an important part of the programme 2 volume change options proposed in brief: • Reverberation chambers • Movable ceiling • Movable ceiling was retained, prior to start of acoustic design, reverberation chambers excluded as being too expensive Design Concept Concert Hall Floating Side Balconies Signature of inner and outer room Design Concept – Long Section Intimacy – acoustical and visual Acoustic Measurements Opening Week (1) Opening Week (2) Opening Week (3) Multipurpose auditorium • Described in the program as: – The multipurpose auditorium shall mostly be used for performances using electro-acoustics, and shall be highly flexible. The auditorium shall have a reverberation time changeable between ca 0,8 and 1,4 sec for the midfrequencies (5001000Hz), the changes shall be performed with the use of banners or elements with one absorbing, one reflecting surface. These will give changes in reverberation for treble/mid-frequencies. To handle the need for the large changes of the reverbeation time, we must, as a compromise, include a certain amount of permanent bass absorbers» Multipurpose hall • Main configurations: – ”theatre/show” • Fixed seats, telescope • Orchestra pit lift lower to make a ”stage front” – ”music theatre” • Fixed seats, telescope • Pit open • First row of seats same height as stage – ”rock” • Flat floor • Band on raised stage in back-stage area. Multipurpose hall • Variability – Seating • Parterre seating telescopes and on lifts. Can be removed totally – Curtains in auditorium • Transverse curtains behind technical bridges. • Roller curtains on side walls • Manual curtains above the grid, on all walls – Stage curtains • Two sets, one more reflective, on absorptive • Fixed absorption – Ceiling above grid – Side and rear stage ceiling – Side and rear stage wall surfaces – Other surfaces ”optimized” for bass absorption Multipurpose hall • Acoustic criteria – Full measurements has not yet been done – Initial measurements indicate that minimum RT is around 0,8 s@mid but maximum is about 1,2 s@mid, in other words a little less than the requirements – Extra fixed absorption was added in the stage area. – Some extra curtains in the auditorium has been suggested. Part 2: Visit of the rooms We shall stop Powerpoint presentations here and now invite you for a tour of the building including both rooms and the acoustic joint. Come and join us!