[ 19. November 2018 ]

DEGEM News – BERLIN – Forschungskolloquium über Line Source Arrays

Von: Steffens, Jochen via ak discourse
Datum: Sat, 17 Nov 2018
Betreff: [ak-discourse] Forschungskolloquium über Line Source Arrays

Liebe Kollegen und Studierende, liebe Interessenten an Veranstaltungen am Fachgebiet Audiokommunikation,

das Forschungskolloquium am kommenden Dienstag, 20.11., um 16.15Uhr widmet mit sich dem Thema Line-Array-Lautsprecher. Konkret wird Florian Straube einen Probevortrag der Disputation seiner Dissertation mit dem Thema Optimized Geometric and Electronic Wavefront Shaping with Line Source Arrays for Large-Scale Sound Reinforcement halten. Eine Kurzzusammenfassung über den Vortrag finden Sie, wie immer, am Ende dieser E-Mail.

Bitte bedenken Sie, dass das Kolloquium diesmal ausnahmsweise im Hybrid Lab stattfindet.

Herzliche Grüße und Ihnen allen ein schönes Restwochenende
Jochen Steffens


PD Dr. Jochen Steffens

Wissenschaftlicher Mitarbeiter

Fachgebiet Audiokommunikation (Sekr. EN-8)

Technische Universität Berlin

Einsteinufer 17c

10587 Berlin

Büro: +49 30 314 29161

Line Source Arrays (LSAs) are used for large-scale sound reinforcement aiming at the synthesis of homogeneous wave fronts for the whole audio bandwidth. The deployed loudspeaker cabinets are rigged with different tilt angles and/or are electronically controlled in order to provide the intended coverage of the audience zones and to avoid radiation towards the ceiling, reflective walls or residential areas. In this thesis, different frequency domain optimization schemes for the geometric and electronic wave front shaping with LSAs are revisited, compared and enhanced. For that purpose, an analytical approach for finding appropriate tilt angles of the LSA cabinets, denoted as polygonal audience line curving (PALC), and a mixed analytical-numerical approach for optimizing the individual loudspeakers’ driving functions, referred to as line source array venue slice drive optimization (LAVDO), are introduced. LAVDO is meant to overcome the non-smooth frequency responses resulting from pure numerical frequency domain approaches. A mathematically explicitly formulated framework serves as basis for all calculations. This incorporates a modified complex-directivity point source (CDPS) model for ideal as well as measured loudspeaker data providing realistic sound pressure levels, an enclosed geometric model in order to exactly specify the source and receiver positions of the LSA configurations and the consideration of practical loudspeaker multiway designs with respect to the frequency crossover filters. Both straight and curved LSA configurations are analyzed for exemplary sound reinforcement venues. The results are evaluated with the help of a comprehensive set of graphical representations and technical quality measures for sound field as well as source-related characteristics. Finally, the conversion from optimized driving functions to practical finite impulse response (FIR) filters is considered.