Acoustic Acoustic Control Systems BV Acoustic Acoustic Control - PowerPoint PPT Presentation

Acoustic Acoustic Control Systems BV Acoustic Acoustic Control Systems BV Control Systems BV Control Systems BV GARDEREN GARDEREN THE NETHERLANDS THE NETHERLANDS THE NETHERLANDS THE NETHERLANDS www.acs.eu www.acs.eu

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ACOUSTICAL ENHANCEMENT and THEATER and MULTI-PURPOSE hall design presentation for the Concert Hall Research Group Monday July 26. 2010 The Lensic, Santa Fe, NM Arthur van Maurik & Keith Vanderkley

Todays Live Music Program • 1. Music at 1.8 seconds RT60 • 2. Music System off (short) y ( ) • 3. Stepping through the settings (short piece) • 4. Sound Source demo,trompet player walks , p p y around system while switching on/off • 5. Invitation to walk around and experience p the homogene spread of sound. Come on stage as well, but do not touch the musicians.

Different kinds of sound require different types Different kinds of sound require different types of acoustics of acoustics f f ti ti Speech: Besides strong direct B id t di t sound speech requires support form early reflections and minor reverberation. reverberation Reverberation time 0.7-1.1 seconds Symphonic music: Symphonic music: Symphonic music sounds best in an environment with both Organ music: supporting early reflections For organ music long g g and significant reverberation. and significant reverberation. reverberation times (2-5 seconds) Reverberation time are required to produce the 1.7-2.3 seconds. characteristic sound.

Acoustic Control Systems (ACS) A ti C t l S t (ACS) • A system to create variable acoustics in multi- y functional halls • Idea: simulate an acoustically ‘ideal’ room in y the existing space • Concept: (a spatially under sampled variant of) Wave Field Synthesis (WFS), paying much attention to spatial naturality • Technology: - Past: analog (shift register principle) - Present: digital delay matrix

The ‘ideal’ hall V Variables: shape, volume, absorption coefficients i bl h l b ti ffi i t

The ideal hall simulated in the real hall

For each microphone: a ‘vector’ of delays Δ t 1 1 Δ Δ t N Δ t 1 Δ t 2 2 Δ Δ t 2 - - - - - - - - etc Δ t N

The Huygens principle

Wave Field Synthesis • It was introduced, as a concept for spatial sound reproduction without sweet spot d d ti ith t t t limitations, by Guus Berkhout (TU Delft) in the 1980s and further developed by the TU Delft 1980s and further developed by the TU Delft group and, later, also by others (NB EU “Carrouso” project) p j ) • WFS is based on Huygens’s principle and the yg p p Rayleigh representation theorems

Sound you hear in an indoor environment can b be divided in three different time windows di id d i th diff t ti i d 1. direct sound and very early reflections 2. early reflections: Sound that arrives from 20 to 80-100ms after the direct sound 3. late reflections or reverberation: Sound that arrives after 80-100 ms. Each of the different time windows influences specific attributes of our perception of sound

Typical features of ACS Typical features of ACS ACS offers acoustical solutions for different situations and places for – Listener • Reverberation in Hall R b ti i H ll • Early reflections in Hall – Musicians • Foldback to stage • Orchestra Shell on stage

Changing acoustics with ACS Changing acoustics with ACS The Acoustic Control System is an electro-acoustic system that produces the desired reflection pattern without changing the physical attributes of the hall • ACS increases freedom for both the acoustician and the architect • Compared with the costs of architectural changes to the building, ACS offers a very high value for money ff hi h l f • By changing the architecture of the building alone it is impossible to reach the same flexibility as with ACS the same flexibility as with ACS • ACS can be installed in a building without (severe) changes to its architecture architecture • ACS is a specially developed for change of acoustics in halls, it honours the generic properties of sound that are defined by the theory of physical g p p y y p y acoustics

Changing acoustics with mechanical devices Changing acoustics with mechanical devices

an ACS system is an investment Design the Hall volume for speech and already save millions in architectural costs. ACS provides the user with additional means to enhance the income of the hall once a system is installed.

An ACS-system can be changed and An ACS system can be changed and adapted to new architectural circumstances instantly and forever. circumstances instantly and forever. In some cases systems moved with the owner to newly build or In some cases systems moved with the owner to newly build or rebuild halls, making an ACS system a good investment.

ACS has specific solutions for Early Reflections and Reverberation on stage and g for the audience in the hall • Separate multi-channel matrices (again typically 18 to 24 S t lti h l t i ( i t i ll 18 t 24 channels)for early reflections and reverberation allow for very accurate control for merging the architectural parameters and electro acoustic enhancement electro acoustic enhancement • The ability to control the energy fed into almost individually loudspeaker allows for a close approximation of the way sound l d k ll f l i ti f th d waves propagate naturally

ACS provides very homogene energy around the whole hall. Almost d th h l h ll Al t everybody gets the same music for the ti k t th ticket they buy. b During the demo we will invite you to walk around and experience this. p

The ACS system advantages in random order • It does not limit the dynamics. (Compressing / Companding always means coloration) • It is extremely silent, no audible noise and distortion • ACS offers the best top end audio/acoustical treatment available to create the desired acoustics, to create variable acoustics and/or ti t t i bl ti d/ repair the existing acoustics.

While creating acoustical enhancement, ACS will in no way touch the direct y sound

The ACS-system is multi-channel (typically 18 to 24 input channels ) (typically 18 to 24 input channels ) • The multi-channel solution secures accurate positioning of p g the sound sources • It avoids localisation of the loudspeakers used. • Even in very complex orchestral settings it assures that the sound from a single instrument is perceived as coming form the exact position on stage. (sound source definition) form the exact position on stage. (sound source definition) • While improving the way sound propagates trough the hall, it makes sure that the sound source stays confined to the place it originates, ensuring the sound source doesn’t th l it i i t i th d d ’t grow bigger than it should be. (spatial properties)

ACS produces the correct atmosphere for the musicians on stage for the musicians on stage • The ACS orchestra shell extension will improve the ensemble playing conditions on i th bl l i diti stage and can even be used to enhance natural shells natural shells • The foldback extension renders reverberation back to stage, giving the musicians information of how the hall is responding to their play. The acoustics of the hall will become a part of their play allowing them to become a part of their play allowing them to play ‘lighter’

1 on 1 with the consultants ACS believes in close co-operation with consultants and architects leads to the best solution.

Microphone Pick-Up Microphone Pick Up The ACS system is typically configured to pick up The ACS system is typically configured to pick up in the direct sound field but it can, if desired pick-up sound anywhere in the hall, even in the reverberation tail or a mixture of all before If you believe that will bring the desired solution.

ACS’s tuning process is balanced such g p that including fine tuning it typically takes no more than 2-3 days to get it y g 100%right.

Some ACS parameters Some ACS parameters dB dB 2 2 1 1 1 1 ER ER ER ER 0 0 -1 -1 sec sec Early and Later energy Early and Later energy

Tuning of an ACS system. Tuning of an ACS system.

ACS provides a system that continues to work for many, many years. It hardly y, y y y requires maintenance

Wrapping Wrapping- -Up, Typical features of ACS Up, Typical features of ACS • ACS uses multiple microphones recording the direct sound field • ACS uses multiple microphones recording the direct sound field of the performers with a high spatial resolution. It enables the generation of reflections with a natural spatial distribution for all source positions source positions • ACS is a multi-channel system that means that every channel can be fed with signals with the correct timing and volume, where every b f d ith i l ith th t ti i d l h microphone is fed to all channels