It is described the integration of user tracking data into a WFS system and the use of such data to simulate directive focused and distant sources in combination with a room simulation based on measured room impulse responses. Section 2 reviews the derivation of the operator used to calculate the loudspeaker signals. In section 3 the single-useropt...
The installation and optimization of acoustic enhancement systems requires a large amount of experience. The verification in terms of measurement is most of the time done using conventional reverberation and acoustic parameter measurements according to ISO 3382. This is a good solution for diffuse sound analysis and general examination of early ref...
Audio reproduction in small enclosures holds a couple of differences in comparison to conventional room acoustics. Today's car audio systems meet sophisticated expectations but still the automotive listening environment delivers critical acoustic properties. During the design of such an audio system it is helpful to gain insight into the temporal a...
Die vollständige Beschreibung eines Schallfeldes ist ganz allgemein über die Darstellung des Schalldrucks p in Abhängigkeit vom Ort (x,y,z) gegeben. Die Ermittlung dieser Schalldruckverteilung kann prinzipiell über entsprechende akustische Simulationsprogramme oder durch den Einsatz von Messtechnik zur Erfassung realer Schallfelddaten erfolgen. Die...
Current Wave Field Synthesis (WFS) rendering realizations consist of large structures of audio signal processing components (filters, delays, amplitude weighting) that are controlled by complex algorithms based on the virtual source's properties. It is proposed a set of tools that is used to analyze the underlying WFS coefficient calculation algori...
Zur Erzeugung virtueller akustischer Realitäten sind verschiedenste Wiedergabetechniken in Gebrauch. Jedes Verfahren bedingt eine bestimmte Anordnung und Ansteuerung der Schallwandler. Beispielsweise lassen sich durch Zusammenfassen von mehreren Lautsprechern zu Gruppenstrahlern (Array) und entsprechender Wahl der Ansteuerung solcher Arrays spezifi...
Spatial audio reproduction used to concentrate on systems with a low number of loudspeakers arranged in the horizontal plane. Wave Field Synthesis (WFS) and NHK's 22.2 two systems promise better localisation and envelopment. Comparisons of 22.2 with 5.1 concerning spatial attributes on one hand, and evaluation of spatial properties of WFS on the ot...
The usage of advanced audio processing algorithms in products has always been limited by the available processing power. For powerful concepts like the wave field synthesis (WFS) the performance is limited by the execution speed. In the past it was possible to increase the performance of digital signal processors by increasing the clock rate. The n...
An ultrasonic apparatus based on a mode conversion technique is described. It involves the measurement of the velocity of both compressional and shear waves in prism shaped specimens with only one transducer. The shear waves are generated through mode conversion at the interface between water and the specimen under test. The optimum coupling of the...
Am Fraunhofer Institut für zerstörungsfreie Prüfverfahren (IZFP) wurden bereits mehrere unterschiedliche Array-Systeme entwickelt und erprobt. Mit dem aktuellen, dieser Arbeit zugrunde liegenden Prüfkopf wurde ein 256-elementiges Matrix-Array realisiert. Ebenfalls wurde eine Sendeelektronik entwickelt, um die vollelektronische dreidimensionale Scha...
