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Brüel Acoustics
Applied Acoustics
Prof. Mattia G. Mario


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Consulting Services: First in Sound and Vibration

Specialist in ACOUSTICS:

To Advance Techniques in Acoustics and Noise Abatement Services

Sound, Noise, Vibrations, Ergonomics,
Training, Research & Development in Acoustics

Sound Correctors (Absorbers-diffusers) - Instrument Services

Brüel Acoustics is a new Company with a long experience: founded by Prof. Mario Mattia and Prof. Per V. Brüel, famous scientist expert in acoustics and pioneer in Acoustics, confered with honors and many honory degrees from all over the world for the important contribution provided in the field of scientific instrumentation to measure and analyse sound and vibration, after he sold to the German AGIV the Brüel & Kjær shares.
Our office is in Roma EUR, a modern area, where we have a show room to present our products and where customers are welcome.

ROMA OFFICE (pdf 212 Kb)

President of the Brüel Acoustics is Prof. G. Mario Mattia, coming from 25 years of experience in B&K, with Prof. Per Brüel.

The managers are people with a great technical acoustical knowledge plus experience in electronic and physics science, they manage the activity with full freedom helping each other across the border lines to solve technical and commercial problems.

We are an Organisation, which on a solid physical basis and long axperience can help to solve acoustical problems (noise and vibration), give better communication possibilities and a better working climate.
Our best selling tool is our experience and knowledge in the acoustical field.
As specialist in many field of acoustics we can solve even difficult problems for the customer.
We can make all necessary measurements e. g. noise levels, noise analysis, noise distributions, sound insulation, reverberation times, sound absorption, intelligibility STI, vibration analysis.
We are also selling products and hardware for helping the customers to have their problems solved.
Noise barriers! (Not in sales!)
We have our own ideas, e. g.: the Speech Transmission Index (STI) is more important than Reverberation time.
As a consequence we have developed a new instrument for intelligibility (STI) Type 44BA, which is unique.
It is light and easy to transport; the transmitter has the shape of a human torso with an head like a sphere.
In this way the directivity pattern will automatically be correct and the head is a perfect monopole.
Besides we believe that acoustic instruments, which simulate human beings, should be formed as spheres.
In this way the instruments could be lighter, stronger and more correct and cheaper than using rectangular boxes.
Human Head and Body Directivity Speaking Head 45BB
We also felt there was a need for a combined absorber and distributor, optimising the room ergonomy and the speech intelligibility, which is easy to install and which could be send to the clienteles as a flat package.
For the time being we are producing and selling absorbers-diffusers AcoustiCone® type 61BA and AcoustiCassini® type 61BB were the absorption and distribution properties could be adjusted to the customer's need.
Some variants are absorbing without using mineral fibres and others are completely hermetic enclosed for use in hospitals and in the food and drug industry.
To be able to deliver an absorber with a specific absorption as function of frequency we have built two new Standing Wave Tubes (SWTs) Type 40BA and 40BB; the 40BA SWT cover the frequency range from 90 Hz to 6000 Hz with two tube diameters.
The instrument can also check intensity probe according to IEC new standard for I-probes.
The Low Frequency SWT Type 40BB cover frequency from 40 Hz to 400 Hz for a 40x40 cm2 sample.
With an intensity probe it is possible to measure reflections up to around 10 KHz.
This Low Frequency SWT is made mainly because Brüel Acoustics have constructed two different Anecho Chambers Type 62BA and 62BB which are built in a modular form so that the customer can order any length, width and height.
The 62BA has a 40 cm module and is built of 10 mm Al tubes, whereas the 62BB has a 60 cm module and uses 15 mm Al tubes.
Both rooms are made as the Cremer type and can be installed by the user himself.
The test-rooms are especially good for higher frequency and are therefore ideal for testing Sound Level Meters (SLM) and telephones, all kinds of microphones, electric motors, loudspeakers, household equipment etc.
Both types can be delivered with either absorbing or reflecting floor as is required in many standards.
A special feature is that the absorbing floor easily can be removed, so that the room can be transferred from reflecting to absorbing floor in few minutes.
The removable floor can also be placed on a flat roof where two small towers support the transmitter and receiver respectively.
The absorbing floor absorb the sound which would reflect from the floor between transmitter and receiver.
In this way an extreme large test-room is built, which can be used when the weather permits it.
For increasing privacy in banks, hospitals, doctors and lawyers waiting rooms we have developed the AntiTell Type 45BA.
This small generator is a sphere of 11 cm secure for IM radiation.
The generator has a noise spectrum just equal to the most important speech spectrum, so that only the intelligibility is reduced without producing unnecessary noise.
The volume is regulated for a "noise perfume" until the RASTI figure is below 40%.
Brüel Acoustics are participating in several research projects.
Larger projects of a more general character are carried out together with universities and supported financially by EU.
We have recently finished a project on energy flow in structures together with Florence University.
We are working on a project on absorption as function of angle of incidence.
We hope to start a large project concerning an acoustic warning system for landing aircraft.
Brüel Acoustics can help clienteles with technical advices and makes measurements for them within the following areas:
Acoustical measurements:
SPL's level, LAeq, Lpeak, frequency analysis, spectrum, reverberation time, reports for noise limits in working and life environments, etc.
Intelligibility with STI for schools, theatres, auditories, airterminals, etc.
Acoustical absorption for many kinds of material can be measured using the SWT Type 40BA and 40BB covering a frequency range from 40 Hz to 9 KHz.
We can convert the results for perpendicular incidence to diffuse field which is important for Ray Tracing.
Measuring noise from smaller aircraft for certification purpose. We do the same for cars, trucks, etc.
We have facilities for testing intensity probe in a reverberant field on ± 12 dB in accordance with IEC standard.
We have developed a special test chamber for determining the amount of shedded mineralfibers from sound absorption materials.
In Italy we make also acoustical measurements to prepare the reports to fulfil the national legislation D. Lgs. 277/91, DPCM 01/03/91, D.Lgs. 626/94, Legge n. 447/95, etc..; we can do the same on human vibration, structural vibration, modal analysis; we make NDT (Non Destructive Test) using advanced techniques in acoustic and vibration; we can support, as consulting, researches involving AE (Acoustic Emission).

Prof. G. Mario Mattia is one of the leaders in a medical researc project on TINNITUS as a no profit organization in Rome.

(Not in sales!)

It is well known that we like rooms not too noisy and with a reverberation time not too long: we need the right sound absorption and diffusion with the highest intelligibility of speech and music for a "good acoustics".
Usually we find environments with surfaces, walls, ceiling, floor very "hard" and with high sound reflection: the acoustical ergonomics is very poor, the speech communication very difficult and the quality of the musical sound is poor and unpleasant.
We have serious acoustical problems in offices, class rooms, restaurants, refectories, canteens, gymnasiums, swimming-pools, cinemas, dance-hall, concert-hall, theatres, pubs, etc. etc., where the sound waves can oscillate back and fort with low attenuation and generate "flutter echoes, standing and travelling waves".
The AcoustiCone® is an unique apparatus for the correction of the environmental acoustics.

Il risultato oltre che esteticamente valido è stato veramente sorprendente sotto l'aspetto sonoro.
Invito tutti gli appassionati di Hi-end a riflettere sull'importanza che assume l'acustica ambientale sul risultato finale della riproduzione musicale.
Ci si incaponisce a sostituire cavi ultra costosi e altri componenti quando con una frazione della spesa di questi si può provvedere ad un trattamento dell'ambiente con dei benefici nettamente superiori in termini di timbrica, di dinamica, di palcoscenico sonoro e di assenza di risonanze.
Un cordiale ringraziamento. Piero Barra


AcoustiCone ®: The acoustical perfect equilibrium.


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