LANFRANCHI Ingénierie Acoustique

Chemin de Corjon 2
CH-1042 Assens
Switzerland

Tél. +41 21 881 32 88

www.lanfranchi.info
e-mail : info@lanfranchi.info

Founded : 1992
Objectives : Services, studies and experimentation, thanks to our autonomous laboratory.
Contributions to metrology : Researches to fill gaps in metrology. Development of a sophisticated computerized equipment allowing measurements of very small surfaces, both in the laboratory and in situ, in order to obtain the best results with certainty.
Contributions to new notions:
 Our scope of expertise has been improved by the introduction of new notions in acoustics such as self-shielding, isotropic reverberation, and accumulation.
Special
researches :
 Discovery and development of absorbing resonators based on the Kirchhoff black body principle.
Quality Control: For the Gustav Mahler Hall, as for other successes, we evaluated the acoustical parameters thanks to a very-high-fidelity quadraphonic reproducing equipment, allowing the definition of what type of sound and how much should come from each direction.
Sphere of application : Every new building and renovation. Every project where site protection is important.

We consider that good acoustics belong to the quality of life and encourage creativity. With this in mind, we have no " small " projects. In every realisation we respect the end user, especially the performers and the public. We treat not only polyvalent halls, concert halls, operas, and churches, but also offices, cinemas, and schools.

Our strength is in having questioned the totality of acoustical theories with the aim of extracting the best and eliminating what had no basis. We have established a link between the discoveries of psychoacoustics and accepted elements of classical acoustics. We have extracted fundamental choice criteria. Several details have been clarified and the Gustav Mahler Hall in Toblach (I) is a brilliant example thereof. It is compared to the world's best realisations.

The acoustical renovation of the Jesuit church in Lucerne (CH), used in particular for the International Festival, is our most recent success. Applying our research results has literally transformed the acoustics of this impressive volume of more than 18'000 m³.

" The methods proposed by some acousticians of renown, based on their measurements and according to their expert knowledge, did not lead to any satisfactory results. Maurice Lanfranchi's solution based on his own resonators has two advantages. On the one hand the method is effective. On the other, these resonators are invisible from the nave and the aesthetics of the church is entirely preserved " (Eric Singer, Director of the Lucerne Festival, Press release, 21.3.2003)

The acoustics have been balanced thanks to ad hoc absorbing elements.150 m² of wall have been fitted with them. The improvement in the acoustics is striking (Peter A. Mayer, Luzerner Woche, 28.3.2003).

Our director Maurice Lanfranchi has solved apparently insoluble problems. To succeed he has specifically developed very effective methods of in situ measurements. His excellent knowledge of information technology allows him to perfect his programs using powerful algorithms, liable to bring to light details unknown till now.


Some significant references

Gustav Mahler Concert Hall, Toblach. 1000 resonators installed in the ceiling and walls provide an ideal reverberation and complete the studies performed by Prof Dr D Baumann of the University of Zurich on the shape of the hall.

Bolzano Opera. We have checked the work of Müller-BBM, the world's largest acoustic firm. Our measurement technology acts as a reference.

Archaeological Museum of Bolzano. The acoustics of the hall hosting the famous Oetzi mummy discovered in a glacier. Ideal treatment of a semicircular hall.

Audition Hall of the Musicology Seminar of the University of Zurich. Development of resonators with an exceptional efficiency, with as = 1.7 at 250 Hz !

The Semblanet Mill Cellar in Martigny. Development of specific resonators hidden by photographs.

Social School of Music in Lausanne. Movable resonators which equalise the reverberation time, fully respecting the timbre of the instruments, voice included.

Polyvalent Hall in Châble. Transformation of the hall into a true concert hall thanks to an electroacoustic system which increases the reverberation time from 1.3 to 2 seconds, whatever the crowd.