Optimized geometric and electronic wavefront shaping with line source arrays for large-scale sound reinforcement
Year: 2019
Type: dissertation
Abstract: Line Source Arrays (LSAs) are used for large-scale sound reinforcement aiming at the synthesis of homogeneous wavefronts 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 reflective ceilings, sidewalls or residential areas. In this thesis, different frequency domain optimization schemes for the geometric and electronic wavefront 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 purely numerical frequency domain approaches without additional frequency-connecting constraints. 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.
Source: DepositOnce
Author: Straube, Florian
Language: English
Topic: Speech and Audio Processing
Subfield: Signal Processing
Field: Computer Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2962971569