Agostino Troll, Balaz Bauphysik, Germany

Balaz Bauphysik and Qsources met at the DAGA conference in Germany where Agostino Troll – acoustician at Balaz Bauphysik – was immediately impressed by the excellent sound power to weight ratio of the 3.1 kg Qohm omni-directional sound source. Both companies kept in touch which resulted in the purchase of the Qohm – sound source and the Qam – amplifier by Balaz Bauphysik.

Balaz Bauphysik has been using the Qsources equipment for doing different types of measurements. The sound source and amplifier combination was used in the reverberation room at the Fraunhofer Institute for Building Physics (Stuttgart) as well as on different construction sites. Agostino commented: “Qsources Qohm sound source is great for measurement of transmission losses in buildings in a wide frequency range. Light weight combined with a fantastic sound power output. Great job by the Qsources team!”. Agostino further added “We had a minor issue with the remote control of the Qam amplifier which Qsources resolved very quickly; good customer service.”

Attila Balazs Nagy ,Reziduum Ltd., Hungary

“The high accuracy of the Qohm2 speaker gives me confidence in my measurement results, whereas its elegant and professional appearance alone astonishes and satisfies the clients: a good start for all consultancy projects.
Next to this, the Qohm2 speaker and Qca amplifier are small and lightweight, which facilitates the usage of trolleys and saves me both time and energy in setting up and transferring the system from room to room.”

Dr. Thomas Delaunay, University of Montpellier, France

We use Qsources Qohm & Qam for practical work and workshops in the University, especially for students who are in a professional acoustic curriculum. Students for example use the source for qualification rooms projects they have to realize for various sites, such as meeting rooms, operas or theaters.

We perform acoustic tests at various sites so we need high power to cover large sizes and advanced insulations. Directivity is also crucial and we have to deal with an omnidirectional sources to test acoustic room parameters (direct sound / reverberation ratio, intelligibility, etc.) avoiding directivity compensation computation.

Ten years ago our students have built an omnidirectional source based on a very well wood factory 35cm diameter sphere composed by 12 high powerful 5” speakers. Compared to this sound source we were very impressed with the weight of Qohm. The high reliability of Qsources Qohm and its very low weight and power provide no restriction for student to deal with various size or insulated sites. Furthermore, our testing and measurement materials are usually transported by trolley or bus which is now also much easier.

In addition with Qsources Qohm, the Qam is a convenient amplifier due to presence of both with and pink noise as well as with presence of an input and output signal. It’s a crucial way to combine Qsources devices with acquisition and computation set to get impulse response or to perform tests with personalized signals.”
  Dr. Ir Pieter Schevenels, PS-Acoustics BVBA , Zonhoven Belgium  
  “We use the Qohm omni-directional sound source together with the Qam amplifier for all our building acoustics measurement for our acoustical consulting office, including measurements of airborne sound insulation (ISO 140-4), façade sound insulation (ISO 140-5) reverberation (ISO 3382-2 and as correction for insulation measurements in the ISO 140 series) and acoustical parameters in landscape offices according to ISO 3382-3. The light weight makes it comfortable to change positions within a room and to travel from room to room, which consumes often a large time of a measurement campaign, since the measurements themselves only take a couple of minutes. The maximum power is overwhelmingly loud and sufficient for measurement of very well insulated partitions.”  
  Mr. Michel Karroum, TOEC Ltd Turin Italy  
  “We have been using the small Qsources source to perform testing at various larger and smaller sites for building qualification tests. The source and amplifier have shown to be reliable and I use them at my mayor client sites like Generali assicurazioni, UBI Leasing, Unicredit, etc.
Now, it is difficult to imagine going back to using my other heavy sound source again. In using the Qsources set we have gained both in efficiency and flexibility”  
  Prof. Wieslav Woszczyk, McGill Recording Studios, Schulich school of Music:  
  “To explain how excellent these dodec speakers are. We measure large recording and performace site acoustics, and the Qsources dodec speakers are sufficiently powerful to fill with sound energy, even at some of the largest rooms we have measured. Their output is also well balanced across frequencies so it makes it easier to see all the needed parameters. Great job designing these little monsters. The enclosed photo is from recent measurements made at a relatively short distance (as it shows better on the picture).”  
  Prof. Dr. Gerrit Vermeir, Catholic University Leuven Belgium  
“The Qsources set has been used for room-acoustic measurements and isolation measurements in our laboratory. The experiences have been very positive; small size, easy handling weight, high sound power, high stability of the power during prolonged use, maximum achievable omni-directionality,… Additional advantages were the step-wise fixed levels on the amplifier unit. And, due to the compactness of the source we could use a good microphone stand instead of the large and heavy tripod we previously had to use with dodecahedron sources.”