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2016 Risku Acoustics
2016 Risku Acoustics
2016 Risku Acoustics
Architectural acoustics
Room acoustics Juhani Risku, architect, acoustician 2016
NTNU SW Innovation Labs
Boston Symphony hall, 1900, Architects McKim, Mead and White, acoustician Wallace Clement Sabine
2016 Risku Acoustics
Studio Auditorium Concert hall Church
Room acoustics – meta-architectural approach Material, structure and formgiving in one package
2016 Risku Acoustics
Archaeoacoustics – history and archaeology Aeroacoustics – sound and air movement Acoustic signal processing – electronic signals Architectural acoustics – acoustics of buildings Bioacoustics – hearing, ear, the living nature and human Electroacoustics – recording, manipulation, reproduction Environmental noise – noise control & planning Experiemental acoustics and soundscapes – create Musical acoustics – instruments, perception & production Processes – ensure and manage good acoustics Psychoacoustics – humans respond to sounds Speech – production, processing and perception Structures and materials – engineering with sound Ultrasonics – high frequencies in use, radars Underwater acoustics – submarines, fish, water and marine Vibration and dynamics – mechanical systems vibrating
Fields of acoustics – physics, technology and the human Profession, innovation and creation
…………………………… Norway
…………………….……….…………………………………… Sony
……….……………………………… Art & Creation
……….…………..…………………… Science & Slow tourism
..….……………………… Innovation & Industry
……….…………..…….……………… Vitruvian approach
…………..…………………… NTNU architects
2016 Risku Acoustics
Richard-Wagner Festspielhaus, Bayreuth Architect Gottfried Semper, 1876
2016 Risku Acoustics
Architectural acoustics
Sound Basics
2016 Risku Acoustics
Sound basics – no decimals Doubling sound pressure makes difference
27…30…33…36…39…42…45…48…51…54…57…60…63…66…69...72…75…77…80…83…85…88…91…94…97…100…103…106…109…112…115 dB
60,1 or 66,4 dB … do not exist in measured real life
Doubling and halfing sound pressure = +/- 3 db
2016 Risku Acoustics
Sound and human being Ear, ears, natural sounds, artificial sound, noise
Sou
nd
pre
ssu
re,
inte
nsi
ty (
dB
)
Equal Frequency (Hz)
Equal loudness (phons)
Binaural hearing – space Soundscape in a room Open air sound Ear
2016 Risku Acoustics
Speech – female and male voice sehsehha
2016 Risku Acoustics
Haas effect – 3D sound, binaural hearing (stereo) Direct sound, early reflections and reverberation without echo – first 50 ms
Haas effect – precedence/direction effect, two equal signlas to ears within 35 ms, binaural effect
85
Headphones – the concert hall turns with your head
dB
1
88
96
Traffic noise over communication – the child doesn´t hear
2016 Risku Acoustics
Sound and noise Sound becomes noise – unwanted sound = noise
Sound levels and maximum exposure time
Noise isolating ear muffs Noise cancelling headphones In-ear earplugs Barrier & shelter
2016 Risku Acoustics
Sound basics – sound travel Different ways and channels
2016 Risku Acoustics
Flanking – noise control – weakest factor matters Start always from the source, reasons and magnitude
http://www.acousticalsurfaces.com/soundproofing_tips/html/Noise_Transmission.htm
Sound will find the weakest link(s) – sound passes around
• Ceilings – Above and Through the Ceiling Space • Floors – Through Floor and Floor Joist Space • Through Windows • Fixtures & Outlets – Light Switches, Telephone Outlets, and Recessed Lighting Fixtures • Shared Structural Building Components – Floor Boards, Floor Joists, Continuous Drywall Partitions,
Continuous Concrete Floors, and Cement Block Walls • Structural Joints – Perimeter Joints at Wall & Floor, Through Wall & Ceiling Junctures • Plumbing Chases – Junctures Between the Walls & Floor Slab Above or at the Exterior Wall Juncture • Around the End of the Partition Through the Adjacent Wall
transmission
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Sound in space Direct sound, reflection, absorption, diffusion
reflection absorption diffusion
2016 Risku Acoustics
Bending sound and acoustic layers Row boat, lake, mach drag, wave drag and bulletproof vests
Sound barriers
Mach drag, wave drag Bulletproof vest
Acoustic layers
Warm air
Reflecting cold water
Acoustic sandwich - No background noise - All senses open
Acoustic half-pipe - Cool air
2016 Risku Acoustics
Architectural acoustics
Features of structures and material
2016 Risku Acoustics
Acoustic form-giving – basic setups 1 Forms and their fit to acoustics
2016 Risku Acoustics
Acoustical structures – basics Typical structures
Floating floor
Hanging ceiling
Floating floor
Structure, material and joint details
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Weight kg/m2
Ave
rage
so
un
d r
ed
uct
ion
in
dex
(d
B)
Structural basics – light vs. heavy vs. multi-layer Light, double panel and heavy structures
Sound insulation performance of building materials by mass law
2016 Risku Acoustics
Response of different absorbers Porous, panel and cavity absorbers
Porous absorbers
Panel absorbers
Cavity absorbers A
bso
rpti
on
co
effi
cie
nt
Frequency
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Absorption Coefficients Material, structure and thickness
.......
050.0
44332211
AaAaAaAa
VTR
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Wood panels Warmth with wood
Music hall = rectangular forms and hard materials =
2016 Risku Acoustics
Dynamically adjustable acoustics Multi-purpose spaces, from speech to music to speech
Speech Singing Band and orchestra
Adjusting between speech and music, soft and hard
2016 Risku Acoustics
Acoustic form-giving – basic setups 1 Room in room - Noisebox Studio, Karachaliou & Kostopoulos
http://www.achilleasxydis.com/filter/architecture/Noisebox-Studio
2016 Risku Acoustics
Acoustic form-giving – basic setups 2 Jon Burton's Laundry Rooms studio
2016 Risku Acoustics
Acoustic form-giving – basic setups 3 Room in room
2016 Risku Acoustics
Architectural acoustics
Criteria Music halls
2016 Risku Acoustics
Acoustical Criteria • Liveness or Reverberance • Clarity vs. Fullness • Loudness • Intimacy • Warmth vs. Brilliance • Uniformity and Diffusion • Texture or Smoothness • Envelopment • Balance or Blend • Sense of Ensemble or Performer Satisfaction
Descriptive acoustical criteria Dry – dead, clarity, intimacy, brilliance…
http://www.phy.davidson.edu/FacHome/dmb/py115/RoomAcoustics.html
“blend”: all seats hear all instruments
“ensemble”: musicians can hear themselves
2016 Risku Acoustics
Descriptive acoustical criteria explained Dry – dead, clarity, intimacy, brilliance…
Liveness or Reverberance: Characterized by the reverberation time of primarily the high and medium frequency ranges. Determined by volume of room and effective surface area. Can be altered by changing area and nature of absorbing materials. Suitability depends on nature of sound or music. A room with too short a reverb time for a particular type of music may classified as "dry" or "dead" while one that is too alive or has too long a reverb time may be called "muddy" or "watery".
Clarity vs. Fullness: Measure of intensity of the direct sound relative to the reverberant or reflected sound. The greater the reflected intensity, the more "full" the room is perceived and the less clear the spoken word or fast or highly articulated sections of music are perceived. Clarity is sacrificed in a "muddy" room but a lesser degree of clarity enhances slow passages of music from the romantic era. To achieve greater clarity or "definition" the entire audience should be close to the stage and have an unobstructed view. This can be accomplished by placing performers on a raised stage and perhaps a raked stage, and by placing the audience on a sloped floor or in balconies.
Loudness: A longer reverb time contributes to the "loudness" of the hall since loudness is a measure of the average power detected by a listener. The relative intensities of ambient and external noise levels are also a factor and should be minimized.
Intimacy: Connected to clarity. The time between the arrival of the direct sound and the first reflection determines the listener's perceived proximity to the performers. An intimate feeling occurs when the initial time delay is between 8 and 20 ms. The more popular halls have a smaller seating capacity because they are generally louder and more intimate.
Warmth vs. Brilliance: This character is determined by the reverb time of the low frequencies relative to the medium and high frequency ranges. In general, the reverb time is a little longer for frequencies below 500Hz than those above. For a nearly constant reverb time as a function of frequency, the room may be classified as "bright" or "brilliant". The longer the lower frequency reverb time is the warmer the room. Yet too long and the room sounds muddy. Most highly regarded concert halls are classified as warm.
Uniformity and Diffusion: Uniform spatial distribution of both direct and reflected sounds throughout the audience. Uniformity in the direct sound can be achieved by minimizing the distance between first and last rows, e.g., a shallow hall with several balconies. Hot spots, caused by the focusing effect of curved walls or domed ceilings, reduce uniformity as well as do dead spots or "shadows" caused by physical obstructions or balcony openings. Objects that diffuse sounds of all wavelengths are necessary for good uniformity.
Texture or Smoothness: For a smooth room there should be no more than 20-30 ms between successive reflections reaching a point in the audience and the intensity of the reflections should smoothly die away in time. Loud echoes can be avoided by not using large flat highly reflecting surfaces and by using sound diffusers of different sizes.
Envelopment: Early reflections, those arriving in the first 100 ms, should arrive from all directions in order to give the listener a sense of envelopment. Recent designs have given more attention to the importance of lateral reflections. Organ music requires an extreme sense of envelopment. Pipes may be placed above, behind, or to the side of the audience to mask the origin of the sound source. For other types of music, too much envelopment can blur the aural image of the stage.
Balance or Blend: Sound coming from different locations on the stage should have balanced intensities. Somewhat related to uniformity. This is generally a problem for seats close to a wide stage. This situation can be balanced with a low, irregularly shaped ceiling and appropriate onstage reflecting surfaces.
Sense of Ensemble or Performer Satisfaction: The performers must be able to hear themselves and the other performers. There should be many reflections strong enough to be heard by the performers but the reflections should decay uniformly and in a time shorter than the shortest time between notes. Flutter echoes reflecting from parallel side walls must be avoided. Acoustic shells increase the sense of ensemble and helps to project more of the sound toward the audience. Ensembles in which members are separated by more than approximately 5 meters easily lose synchronicity and need a conductor to give visual cues.
http://www.phy.davidson.edu/FacHome/dmb/py115/RoomAcoustics.html
2016 Risku Acoustics
Reverberation time Time taken for a sound to decay by 60 dB from its original level
Studios Auditoriums Concert halls Churches
direct sound
reflected sounds
http://www.mcsquared.com/problems.htm http://www.mcsquared.com/reverb.htm http://www.mcsquared.com/music.htm
http://abmp3.me/xqnpjrhw/reverberation-reverberation-mp3-download.html
0,2…0,4 s 0,5…1,0 s 1,5…2,5 s 1,2…1,5 s 3…5…8 s
2016 Risku Acoustics
Reverberation time comparison – concert halls Measured reverberation times of best European concert halls; Lorenz-Kierakiewitz,Vercammen
2016 Risku Acoustics
Early reflections – sound field formation Direct sound, early reflections and reverberation without echo – first 50 ms (1/20)
2016 Risku Acoustics
Reflection from room surfaces Straight, corner, convex, concave
2016 Risku Acoustics
Sound travel – basics Direct sound and reflections
2016 Risku Acoustics
Architectural acoustics
best ones... Music halls
Some of the
2016 Risku Acoustics
Musikvereinsaal, Wien, 1870 Boston Philharmony, 1900
Best music halls 1 Musikvereinsaal vs. Boston Philharmony
2631 seats T500-1000 = 1.8 s
2158 seats T500-1000 = 2.05 s
2016 Risku Acoustics
Staatsoper, Wien 1869 (1955) 1658 seats
T500-1000 = 1.3 s
Best opera houses Teatro Alla Scala vs. Staatsoper
Teatro Alla Scala, Milano 1778 2289 seats
T500-1000 = 1.2 s
2016 Risku Acoustics
Philharmonic Hall, Liverpool 1939 Concert Hall, Turku 1952
Best music halls 2 Liverpool Philharmonic Hall vs. Turku Concert Hall
1002 seats T500-1000 = 1.6 s
1955 seats T500-1000 = 1.5 s
2016 Risku Acoustics
Cultural House, Helsinki 1955 Radiohuset, Copenhagen 1945
Best music halls 3 Aalto’s Cultural House vs. Lauritzen’s Radiohuset
1093 seats T500-1000 = 1.5 s
1500 seats T500-1000 = 1.05 s
2016 Risku Acoustics
Chamber Music Hall, densifying sound field Concept created at IRCAM studios 1990, proposal to Besançon, France 2013
Juhani Risku, architect SAFA, acoustician
2016 Risku Acoustics
Over the audience and over the stage, ceiling clouds and panels produce balanced and
blended sounds for a variety of venues, resulting in a rich, directed sound that the
discriminating audiences have come to expect.
Acoustical ceiling panels – problem solving Lack of reflections from the ceiling
2016 Risku Acoustics
Architectural acoustics
DIY people... ... or professional architects?
2016 Risku Acoustics
Structural basics – DIY people Do-It-Yourself and construction physics in conflict
2016 Risku Acoustics
Structural basics – DIY people can do Do-It-Yourself and construction physics in harmony
High frequences - Carpets, drapes, gobelins, curtains - Max. at ¼-wavelength distances
Low frequences - Bass traps (studios) - Fixed furniture - Max. at ¼-wavelength distances
Balance between absorbants by frequency
Combinations - Bookshelves, boxes, drawers - Sofas, armchairs - Garderobe
Absorption only
Medium frequences - Panel structures (walls, floor, ceiling) - Furniture - Asymmetric placement
2016 Risku Acoustics
Forget about…
… Aalto and Rietveld…
… and egg cartons…
2016 Risku Acoustics
Acoustic design – the architect Architectural and conceptual planning & design in detail
Sketching Concepting Design Build Architectural solution Planning Details On-site crafting
Gantt
Decisions of architectural quality – the power of a pencil
Decisions of material investements – the power resourcing
Uncertainty of quality – the power the unknown
2016 Risku Acoustics
Professional inability Architects don’t care or can’t do
Forms which does not fit to acoustics - Form-giving, function - Quality
Details – wrong use of material and its location Education – lack of architectonic fundamentals Consultant effect – outsiders are involved - acoustic engineers dictate - communication fails - architect a bad customer
Target setting – multipurpose vs. quality
Acoustical design problems Function, need and quality – Architects don´t care
Functionional conflicts Acoustics does not meet needs
Extreme values of reverberation time Echoes Room resonances Focusing of sound or hot spots Balcony and column shadows Bad handicraft and detailing External noise Precedence effect – priority conflicts
2016 Risku Acoustics
Exam: For what do you need lights in a music hall ?
– For notes, and notes only. Thank you.
2016 Risku Acoustics
2016 Risku Acoustics
2016 Risku Acoustics
2016 Risku Acoustics
https://www.youtube.com/watch?v=GkNJvZINSEY Science - Transmission of Sound
http://www.acoustic-glossary.co.uk/definitions-a.htm Acoustic glossary
http://piisami.net/tieto/akustiikka.htm Akustiikan perusteita
https://www.youtube.com/watch?v=qgdqp-oPb1Q Erar, hearing
https://www.youtube.com/watch?v=JPYt10zrclQ How Sound Works (In Rooms)
http://www.armstrong.com/reverb/main.jsp Reverberation time, examples
http://threedb.com/rt.php?lang=en http://www.bobgolds.com/RT60/rt60.htm Rough, but best for now: http://www.amfgrafenau.de/index.php?l=2&mode=shownews&artid=534&groupid=155&subcatid=361&maincatid=155& - http://trikustik.at/rak-rechner/ - http://www.acoustic.ua/forms/Reverberation-RT60.html
Reverberation time, calculation
2016 Risku Acoustics
Architectural process – Agile and lean waterfall The architect should be planning and designing from the beginning to the finalisation