Demonstrating vibro-acoustic reciprocity with a vacuum cleaner!

Our smart vacuum cleaner is just one of the lightweight mechatronic devices buzzing, humming, groaning and scraping around us.

Demonstrating the principles of vibro-acoustic reciprocity on this will not directly improve its sound. However accurate measurement data of vibro-acoustics will improve both numerical models and the understanding of the operational loads on the device.

Vibro-acoustic reciprocity between 300 to 7000 Hz, captured with just a tiny accelerometer, microphone, very small shaker, volume acceleration point source and, not to forget, our vacuum cleaner, is a way to show Qsources has accurate small scale excitation covered !

We had fun putting this demo and video together and, as a bonus, now have a far better understanding of our vacuum cleaner ! It hopefully provides you with an idea on the wide range of potential applications of our products aimed at making the world a more quiet place.

 
 

Sound source suitability for in-situ noise barrier measurements

KU Leuven (Belgium) & Qsources analysed sound source suitability for in situ noise barrier measurements according to EN 1793-5:2016.

This method aims at optimizing the reliability of field measurements of reflection and scattering on barrier surfaces. Measurements took place at the Laboratory of Acoustics at the Department of Physics and Astronomy of KU Leuven.
Qoms2 (monopole omni-directional source) as well as Qohm (lightweight high output dodecahedron) were measured in comparison with a conventional sound source. During this study the direct sound arrival was analyzed using a microphone grid placed in a large reverberant room. Impulse responses where measured using different settings of the DSP controlled Qam measurement amplifier.

A preliminary analysis showed significant differences between the sound field characteristics of the Qsources devices and the ones of the conventional sound source, indicating a potential advantage of the Qoms2 source.

Other interesting tests such as measurements against surfaces with different absorption characteristics are planned in the near future.

Qsources would like to thank KU Leuven and Prof. Dr. Christ Glorieux for the cooperation.

 
 

Determining sound power of fixed machinery

This article investigates how to measure sound emission in an acoustically complex environment by using a reference sound power source.

The reference source method provides fast and low complexity measurements of sound power on-site in arbitrary acoustic environments.
Qsources Qref , a small and lightweight sound power reference source, was used to improve the accuracy of the sound power reference method.

This blogpost was based on an application note and can be read in full below.

How to measure sound emission in an acoustically complex environment by using a reference sound power source

Whilst small and infrastructure independent machinery can be brought into specialized measurements chambers to measure their sound power emission, for larger machines or fixed infrastructure dependent machines this is not possible. A “machine” could also be a pump, an invertor, a cleaning robot, a ventilation, production machine, etc.

In many cases, on-site measurements in their natural conditions is required in which case the measurement conditions can become acoustically complex.

Efficient sound power determination

The reference sound power method is interesting for on-site determination, because it is fast, has low complexity and does not require elaborate equipment.

There is a clear ISO standard 3747 to guide the measurement and processing and provides estimates of worst case accuracy.

The alternative methods include detailed sound intensity scanning and/or inverse techniques. These also allow measurement of the sound power emission. These methods however require a significant time investment and complexity.

The reference power method

The reference source method provides fast and low complexity measurements of sound power on-site in arbitrary acoustic environments.

The reference based procedure includes following steps:

  • Run the “machine” or product in its natural condition and measure the sound pressure spectra at minimum 5 locations.

  • If possible it would be advised to stop the “machine”

  • Place the Qsources reference source against the machine surface, activate, and measure the sound pressure at the same locations

  • Place the reference source against various surfaces of the “machine” if desired to increase accuracy

Calculate the sound power level from the averaged measured sound pressure level differences between machine and reference source

Ideally the measurement surface is as indicated in the illustration, following ISO 7473.  Often this is not possible because the microphones have to be closer; in which case, it is advised to repeat the procedure with another combination of reference source and microphone locations to determine the stability of the sound power.

After defining the reference and measuring surface, the microphone can be placed in position. there will be a total of 5 measurement positions. The details of the various positions is described in the application note which can be downloaded at the end of this page. The Reference sound source is placed in position on the upper surface of the machine and/ or under certain conditions against the sides of the machine.

If desired, the accuracy of the method can be improved beyond the ISO 3747 standard by:

  • Increasing the number of reference source locations on the faces of the machinery, and the number of microphone positions

Placing reflecting panels on around the machinery on the low refection sides

Qref Sound Power Reference Source

Another way of improving the accuracy of the Sound power reference method is by using the Qsources Qref: a small and extreme lightweight sound power reference source.

  • Qref is a well defined monopole source with a high acoustic impedance

  • driver and integrated sensor technology allowing the application of different signals (e.g. equalized white/pink noise, chirps, sine sweeps, MLS)

  • exceeds the ISO 6926 requirements in the 50-8000 Hz bands

  • incomparably lighter and smaller than any other sound power reference of similar output level on the market

  • electronic control is sensing, correcting, steering the driver, and steering the real time power proportional sound power signal

Qref allows a very controlled sound power emission, and even a spherical wave up to 3.6 kHz
The more traditional ventilator based solutions do not have the flexibility of placement agains any “machine” surface, have stronger directionality and can cause can an interference pattern, all increasing meausrement uncertainty.

The Qsources Qref set includes a dedicated Infra-Qsources QamR amplifier and is delivered with an individual certification according to ISO 6926

Unique to Qref compared to currently marketed sound power reference sources is that it can be placed in various positions on the test object, allowing precision and improving the measurement results compared to the Juxtaposition method.


Next to the substitution method or the improved juxtaposition method, Qref also allows measurements in direction of the inversion techniques.

Qref is also extremely suitable in high background noise environments or when the machinery cannot be stopped, the Qref can be used with special signals to obtain stable reference sound power data.

Next to the sound power identification on-site of for example installed machinery or larger installations, Qref can be used for:

  • Regular verification of acoustic rooms for product testing, machinery testing, anechoic rooms, reverberant rooms, including free field decay measurements.

  • Statistical Energy Analysis (SEA) type of measurements of rooms, halls, other acoustically coupled systems and other airborne excitation applications.

The reference method was applied in practice, using an early Qref prototype, on an electric saw. This study describes the complete procedure including required infrastructure and test set-up such as:

  • Different microphone positions

  • Reference Sound Source positions

  • Testing procedure including background reducing FRFs

  • Sound power calculation in 1/3 octaves

Credits

Marius Morariu – Morariu Consultancy Limited
Peter J. G. van der Linden – Qsources bvba

Frequency Response Function (FRF) testing

Watch the recent Simcenter on-demand webinar about boosting digitalization in noise and vibration (NVH) product development and see our Simcenter-products being set-up and used.

Simcenter-Qsources Q-MED Low Frequency Monopole source was used for excitation in vibra-acoustic transfer function measurements.

Q-HSH High frequency shaker was used for modal analysis of CAE correlation. This shaker ensures excitation without damaging the surface with low hardness and changing dynamic stiffness of the structure.

Acoustic transfer function measurement executed in this webinar included Q-MHF Mid High Frequency Volume Source. This source was used to artificially generate noise from outside the vehicle.

In this webinar, you will learn how hybrid modeling uses test and CAE data, how FRF test data can help improve CAE models & how acoustic FRFs support vehicle package NVH design.

Acoustic comfort in atria and large halls

This article discusses acoustic comfort in atria and large halls & the effects of transparent foil roofs. This study was presented by researchers of the Slovak University of Technology in Bratislava in cooperation with KU Leuven faculty of architecture.

The low frequency measurements conducted inside the building of the Berufsbildende Schule in Oldenburg, Germany included In-situ reverberation measurements, Sound pressure level decay and Numerical analysis using room acoustic software.

Thanks to Monika Rychtarikova, Daniel Urbán, Carl Maywald, Lukáš Zelem, Magdaléna Kaššáková and Christ Glorieux and the team of KU Leuven and STU Bratislava for supporting the use of the article.

Measuring low frequency effects of transparent foil roof in an atrium

A recent study conducted by researchers of the Slovak University of Technology in Bratislava in cooperation with KU Leuven faculty of architecture have investigated the acoustic comfort of foil structures used in buildings. These “novel structural skins’” in building design are becoming popular alternative to traditional material such as glass and can contribute to improvement of indoor comfort, reduction of environmental impact and even budget reduction.

Case study

The atrium at the secondary school “Berufsbildende Schule” in Oldenburg was chosen as a case study. This atrium is covered by a transparent 3-layer Texlon® ETFE (ethylene-tetra-fluoroethylene) cushion system. The outer layer is printed for shading purposes. The two air chambers between the three ETFE foil layers of the Texlon® cushion system are stabilize by low inner air pressure.

In situ reverberation measurements & sound pressure level decay

The presented results are based on impulse response measurements in situ, for determination of room acoustic parameters such as reverberation time, early decay time, clarity of sound and speech intelligibility and sound pressure level measurements followed by statistical noise analysis.

The sound excitation equipment for above measurements were performed using Qsources Qohm omni-directional speaker and Qam measurement amplifier.

Qohm, lightweight omni-directional dodecahedron sound source

Extreme light weight of 3.1 kg, and small dimensions allow fast and efficient work.

Omni-directionallity in accordance with ISO 16283
122 dB Lw pink noise level at the full frequency range 50 to 16000 Hz.

The high output from 50 Hz upwards, 97 db Lw at 50 Hz, is even sufficient for larger spaces.

Qam: sound generating measurement amplifier

Qam is fully DSP controlled sound power amplifier for noise and vibration measurements with a very high power/weight ratio for maximum portability. Internally generated white/pink noise signals are available as well as acceptance of any external signal generator.

Qam allows spectral equalization for the coupled sound source. Especially for measurement in difficult small spaces, a low frequency third octave band equalizer allows adaption to the measurement space.

Room impulse response measurements were performed according to ISO 3382 and ISO 18233 using sweep signals generated by the Qam amplifier and Qohm omnidirectional sound source. Measurements were performed for 2 positions of loudspeaker and 34 microphone positions.

Numerical analysis

In the modelling part of the project, nine different alternative materials and measurement situations were simulated using Odeon room acoustic software in order to get insight in the influence of the roofing system on the acoustic comfort in an atrium. A numerical simulation was performed in which noise that is typically present in atria was emitted in the virtual atrium.

The results show that differences between the alternatives should be audible in the low and middle frequencies. This is logical, as for high frequencies the sound absorption coefficient of the three different materials (foil, glass and concrete) are very similar.

At low frequencies, clear differences are present between the alternatives with foil ceiling and the other alternatives. In the most reverberant situation (with highly reflecting concrete walls and floor), the glass ceiling performs better than the concrete celling. In this case, the foil ceiling helps to reduce the sound level with more than 8 dB at a distance of 10metres from the source. In the middle frequencies these improvements are less significant since the porosity of the foil cushions, and glass is as low as the one of concrete. Only in the most reverberant situation, a ceiling based on ETFE slightly (2dB) helps more to reduce the sound pressure level, in comparison with class or concrete ceiling.

Statistical noise analysis was performed for two different sounds (restaurant sound and music), simulated binaurally in each of the nine alternatives. For both types of sound, there are significant differences between the different wall treatment cases. This confirmed expectations, since the distance between the walls is smaller than the distance between the ceiling and the floor, and since the surface of the walls is larger than the one of the ceiling. As expected, the effect of ETFE ceiling is most significant in the reverberant situation.

Results of the study

The study compares acoustic conditions in an atrium covered by foil-based structures, with situations in which the roof is realized by other type of materials, such as glass.
The reverberation time in an atrium with dimensions of approximately 16,5m x 14,6m x 27m and with total area of interior surfaces of about 4570 m2 is significantly influenced by the ceiling material. A clear reduction is achieved in the middle and low frequencies in cases with foil ceiling systems in the ceiling compared to glass or a hard surface such as concrete. The difference in decay of sound pressure level with distance is more significant in low frequencies than in middle and high frequencies.

The effect of ETFE ceiling was most significant in the reverberant situation. At larger distances from noise sources, application of a foil cushion system in very reverberant situations can help to reduce sound with 8-10 dB.

Statistical noise analysis applied on auralized sounds shows clear differences between the three wall material conditions. Noticeable differences in background noise created by the two sound signals (restaurant noise and music) are found between an atrium covered by foil and by the two other roof materials.

To conclude, successfully realized projects with modern foil-based roof structures show the positive impact on acoustic comfort, which can play an important role for the decision of the design of large shopping malls, restaurants or shops.

Credits

This blogpost is based on the research article ‘Advantages of ETFE in terms of acoustic comfort in atria and large halls‘.
Qsources would like to thank the authors and team of KU Leuven and STU Bratislava for supporting the use of the article:
Monika Rychtáriková, Daniel Urbán, Carl Maywald, Lukáš Zelem, Magdaléna Kaššáková and Christ Glorieux.

For further information, please contact: KU Leuven, Faculty of Architecture, Research Department of Architecture: monika.rychtarikova@kuleuven.be

Challenges of acoustic measurements in performance sites….

In measurement situations where control of sound quality and intelligibility are crucial factors, there can be certain challenges to be taken into account. These type of room acoustic measurements include:

  • Room Impulse Responses

  • Reverberation Time

  • Speech Transfer Measurements

Learn why a monopole sound source outperforms dodecahedron speakers.

Why a monopole sound source outperforms dodecahedron loudspeakers

A monopole omni-directional sound source will provide the most accurate room acoustic measurements. These can be applied to any type of closed or semi-closed space (e.g. office spaces, apartment buildings but above all, this level of accuracy is most interesting for measurements in theaters, churches, opera houses and concert halls. When conducting measurements in performance sites, monopole sound sources outperform dodecahedron loudspeakers.

Its a real challenge to take measurements inside performance sites where control of sound quality and intelligibility are crucial factors.

These type of room acoustic measurements include:

  • Room Impulse Responses

  • Reverberation Time

  • Speech Transfer Measurements

Qsources Qohm: a high power dodecahedron for a broad range of measurement applications

The Qsources Qohm lightweight omni-directional sound source is also perfectly suitable to take measurements in musical performance sites. The highly uniform sound radiation from the Qohm source allows controlled excitation of the acoustics of small and large sites. The maximum sound power level of 122 dB Lw and a high output at 50 Hz, 97 db Lw makes the Qohm utmost suitable for a broad area of applications such as airborne isolation testing and reverberation testing.

Possible issues using an omni-directional dodecahedron

Studies show that in the frequency bands ranging from 125Hz. to 1kHz. octaves, all types of omni-directional sound sources can be used. However, above 1kHz. measurements might be afflicted by using for instance a 12-speaker dodecahedron sound source*.

The solution: Qoms2 Monopole speaker

Qsources Qoms2 is monopole omni-directional source which include 2 unique Qsources QP4 drivers.
This small & lightweight source is powerful enough for measurements in any type of performance site. In addition, it’s suitable for broadband measurements in wide frequency range (1/3 octaves: 50-16000 kHz.). Next to the output benefits, the light weight (1.25 kg) and the small dimensions (10.6cm) diameter allow this sound source and its measurement amplifier (Qam or Qca) to be taken on site and set up in a stress free and fast manner.

The Qoms2 speaker is designed to conform to amongst other ISO 140, ISO 3382, ISO 16283 and 14275.

The below directivity plots show that Qoms2 provides a smoother output than our high power, dodecahedron speaker Qohm.

 
 

The below images also show why the measurements of Qoms2 are more precise than standard omni-directional speakers or dodecahedrons on the market.

When measured in tangential direction, the radial pattern showcases nearly perfect omni-directionality.

In axial position, the directivity is nearly perfect up to 4 kHz. & remains smooth, spherical and balanced in the highest octave bands up to 16 kHz.

Conclusion

In summary, the above directivity results would be impossible to achieve using a standard omni-directional loudspeaker given these will show aspherical patterns above the frequency level of 1kHz. For certain type of measurements where intelligibility and sound control are very important, such as measurements of musical performance sites, the Qsources Qoms2 monopole sound source outperforms dodecahedron loudspeakers.

 
 

Qsources developed a custom miniature Wind tunnel reference sound source for TU Delft Aeroacoustics & Wind Energy Research Group

QindW is a custom miniature sound source with very low diffraction and excellent omni-directionality. A narrow and long design allows minimal impact on the flow and minimal feedback from the flow on the source output.

This Low Turbulence Tunnel experiment was part of the NWO-TTW THAMES project: Towards High-Reynolds Airfoil self-noise MEasurementS. The goal was to understand how to improve noise measurements in closed wind tunnels, with particular application to wind turbine blade noise studies.

Learn more about QindW and the experiment below.

Qsources QindW is a Wind tunnel reference sound source. A custom miniature sound source part of Infra-Qsources built for TU Delft Aeroacoustics & Wind Energy Research Group.

QindW is a custom miniature sound source with very low diffraction and excellent omni-directionality. A narrow and long design allows minimal impact on the flow and minimal feedback from the flow on the source output.

With a diameter of 22 mm and a length of 120 mm the disturbance is minimal and much smaller than any other sound source. The frequency range with a long-time stable relation between drive voltage and emitted sound power is 500 – 6300 Hz. The set includes a powering cable with source protection electronics. The sound source can be driven with any signal from random noise to sine sweeps to music signals and can be calibrated for the sound power under different signal settings in an anechoic chamber.

Product Characteristics

  • Frequency range: 500-6300Hz.

  • Length: 120mm.

  • Diameter: 22mm.

  • Sound pressure level: 65dB at 1meter in free field (white noise, 500-6300Hz.)

  • Sound power level: 76dB Lw (white noise, 500-6300kHz.)

  • Amplifier requirement: 100 Watt RMS to 4 Ohm or more

 

Low Turbulence Tunnel experiment

The experiment using QindW took place in the Low Turbulence Tunnel (LTT) at TU Delft. The wind tunnel campaign was part of the NWO-TTW THAMES project (grant 15215): Towards High-Reynolds Airfoil self-noise MEasurementS.

The goal of the project is to understand how to improve noise measurements in closed wind tunnels, with particular application to wind turbine blade noise studies. The test section used in the closed wind tunnel has been modified for better aeroacoustic measurements. In order to improve noise measurements inside the test section, lining materials have been applied at the wall.

The goal of the wind tunnel campaign was to study how the different lining materials improve the noise measurements: by reducing sound reflections inside the test section, and by reducing reverberation inside the tunnel circuit.

The lining materials included:

  • wedged melamine side panels, covered by Kevlar

  • flat melamine foam panels on the floor and ceiling

The microphone array was mounted behind a Kevlar panel, so that it records less noise from the boundary layer of the tunnel (i.e. noise originated from pressure fluctuations in the flow).

Improved aeroacoustic measurements

The test has lead to significant improvements of noise measurements in closed wind tunnels using Qsources’ QindW source to generate noise in-situ, placing it in the center of the test section to study the effect of reflections. The Sound source incorporates two long stroke electrodynamic actuators. The test set-up included flow-off and flow-on measurements.

QindW is a customized product part of the Infra-Qsources range of high quality sound sources. The Infra-Qsources range includes solutions for efficient on-site acoustic testing in buildings, rooms and infrastructure.

Where the QindW is a custom product built by Qsources for TU Delft, another miniature sound source named Q-IND, is available under the Simcenter Qsources range. Specific for the Simcenter Qsources Q-IND are the sensors for a real-time volume displacement signal up to 2000Hz. This is the source strength descriptor which is practically independent from the acoustic environment, providing a basis for reciprocity and modal analysis testing.

The Simcenter Qsources Miniature Volume Source can be used for Airborne Source Quantification (ASQ), Transfer Path Analysis (TPA) as well as Vibro-Acoustic Modal Analysis (EMA). Its miniature size allows accurate acoustic transfer function measurements around intake and exhaust nozzles for airborne source quantification techniques. The FRFs are acquired without the influence of the volume of a large low mid frequency source. Its size makes it ideal to excite structures from inside, like white goods and consumer electronics.

Besides ASQ, the source can be used for scaled modal analysis using the internal volume displacement sensor as reference.”

Credits

The campaign took place thanks to two PhD candidates: Mr. Hugo Bento and Mr. Colin VanDercreek and was supervised by Prof. Dr. Mirjam Snellen, Dr. Daniele Ragni and Dr. Francesco Avallone.

For further inquiries related to this aeroacoustics project. Please contact:

Hugo Bento
Aeroacoustics/Wind Energy Research Group
Building 62 – Room 6.08
Delft University of Technology
H.F.MouraoBento@tudelft.nl

Low Frequency Sound Source Q-MED

Q-MED is a low frequency monopole source designed to measure vibro-acoustic transfer functions in and around vehicles.

The negligible diffraction makes it an accurate omnidirectional sound source up to 2,000 Hz. allowing typical vibroacoustic body noise transfer functions measurements including frequency response functions (FRFs).

A recent Siemens Simcenter blogpost provides a step by step approach to obtaining the most accurate results using corrected values for analysis and comparison to avoid influence of the source on the measured FRF.
This article explains how to use the data from the Q-MED calibration report as well as post processing calculations to account for variations of source sensitivity and applying corrections in amplitude.

ISO9001:2015 Certification

Following the audit of SGS, a leading company in inspection, verification, testing and certification, Qsources has successfully gained certification to ISO 9001:2015. The main feature of the ISO 9001 Quality Management system is offering a customer central approach including overall performance improvements and risk-based thinking. We at Qsources are proud to have gained this acknowledgement.

Simcenter Qsources Q-ISH used in modal analysis

A recent Siemens Simcenter blogpost discuses test-calibration of mode shapes. The test set-up includes Qsources Q-ISH integral shaker on the SimRod, a full electric sportscar at Siemens Simcenter. Control of the mode shapes allows modifications to increasing the range of a vehicle and optimizing the drivetrain.

Next to CAE based modal analysis the actual testing supports a balanced development.  However, testing can become expensive. The example of the Simcenter Qsources Q-ISH integral shaker shows that excitation and calculation can be performed in an easy and fast manner. The compact shaker can be attached and positioned easily under any inclination and has a patent protected self-aligning stinger-suspension system. This way the shaker can be mounted directly on the relevant excitation location.

McGill university in Montreal Canada installed a large set of Qohm sources with dedicated equalization equipment

In the recording research centre at McGill, the very light weight omni-directional sources are used in experiments to influence musicians during their performance recording using replay. And, a set of two of the same Qohm sources are also used when going over the world to investigate the acoustics of large performance sites with exceptional acoustic properties. See the 16 sources suspended over the recording area at McGill in the shown photo.

Qsources and Sage Technologies are pleased to start a new cooperation. Sage Technologies will distribute Qsources’ Infra-Qsources product range in the United States of America

Sage Technologies is a manufacturer’s representative company specializing in sound and vibration testing. Sage Technologies was founded in 1989 and is headquartered in Manhattan Beach, California.

Peter van der Linden – Qsources – stated: “Bringing a new solution to the market, worldwide, is not obvious. Experts and consultants have to be able to find our sound excitation solutions and understand the potential for their work. We are excited to have Sage Technologies on board. Sage Technologies is already representing main manufacturers in the sound and vibration domain and is providing valuable training and support. This is the kind of partner we need in the USA to bring Infra-Qsources to the noise and vibration community.

Evro T Wee Sit – Sage Technologies – added: “Infra-Qsources products are a perfect fit within our overall portfolio of products and Qsources will help us to further support and service our customers in the field of building acoustics and industrial applications”

Information on Sage Technologies can be found under: https://www.sagetechnologies.com/

 
 

Further expansion of the Qsources worldwide distribution network: Marubun Corporation becomes authorized partner in Japan for Infra-Qsources products

Qsources is pleased to announce a new partnership for the Japanese market with Marubun Corporation. Marubun Corporation, with headquarters in Tokyo, is a major trading company focused on the industry and R&D field based on electronics technology, providing the best products.

Peter van der Linden, managing director of Qsources, stated: “The Marubun Corporation positively surprised Qsources by their very thorough analysis of the products and preparation of the cooperation. Marubun Cooperation is a significant player on the Japanese market with a broad portfolio. We are even more convinced that the level of information and service that Marubun can provide to its customers is of significant value. It will allow he customers effective use of the Qsources sound sources and other products. We are very pleased to work with Maribun Coorporation and look forward to strong business within this important market”. 

Information on Marubun Corporation can be found under: https://www.marubun.co.jp/

Qsources is expanding its presence in the Polish market thanks to a distribution partnership with EC Test Systems

Qsources is pleased to announce a strong partnership for the Polish market. EC Test Systems Poland is a specialist in vibro-acoustic test and measurement equipment. 

As a highly specialised company, Qsources is constantly looking for opportunities of cooperation in the acoustics, noise and vibration field worldwide. We are very pleased to work together with EC Test Systems. As specialist in acoustic excitation products, the Infra-Qsources range will fit perfectly in their portfolio of strong brands.

more information about EC Test Systems can be found here: http://www.ects.pl/

FAMTECH becomes distribution partner for South-Korea

Qsources, leading in sound and vibration excitation technology, has signed a distribution agreement for the Infra-Qsources brand with Famtech for South Korea. Qsources continues to focus on expanding the Infra-Qsources range in more industries and markets though distribution with world-class companies.

Famtech is a leading company in Test and Analysis service and equipment founded in 1996. The Infra-Qsources range is a perfect fit in their portfolio of diverse measurement equipment.

“We are convinced that our state-of-the art sound sources, amplifiers and other excitation devices will be well accepted in the Korean market due to the customer’s demand for premium products in combination with service, support and education that Famtech offers.” Says Mr. van der Linden, Managing Director of Qsources.

more information about Famtech can be found here: https://www.famtech.co.kr/

Video: Qohm – lightweight omni-directional sound source

A demonstration of Airborne Sound Insulation Measurement using Qsources: Qohm – extreme lightweight omnidirectional sound source – and Qam measurement amplifier.

The test is performed in cooperation with PS-acoustics Belgium.

The consultant is using a previous version of the Qohm dodecahedron.

The newer version includes upgrades however the product specifications are identical.