Automatic Calibration and Equalization of a Line Array System

Loading...
Thumbnail Image
Journal Title
Journal ISSN
Volume Title
Sähkötekniikan korkeakoulu |
Date
2015-08-24
Department
Major/Subject
Acoustics and audio signal processing
Mcode
S-89
Degree programme
TLT - Master’s Programme in Communications Engineering (TS2005)
Language
en
Pages
69+6
Series
Abstract
This final project presents an automated Public Address processing unit, using delay and magnitude frequency response adjustment. The aim is to achieve a flat frequency response and delay adjustment between different physically-placed speakers at the measuring point, which is nowadays usually made manually by the sound technician. The adjustment is obtained using four signal processing operations to the audio signal: time delay adjustment, crossover filtering, gain adjustment, and graphic equalization. The automation is in the calculation of different parameter sets: estimation of the time delay, the selection of a suitable crossover frequency, and calculation of the gains for a third-octave graphic equalizer. These automatic methods reduce time and effort in the calibration of line-array PA systems, since only three sine sweeps must be played though the sound system. For verifying the functioning of the system, both simulated signals and measurements have been conducted. A 1:10 scale model of a line array system has been designed and constructed in an anechoic chamber to test the automatic calibration and equalization methods and the results are analyzed.
Description
Supervisor
Välimäki, Vesa
Thesis advisor
Välimäki, Vesa
Keywords
line array, public adress, crossover filtering, delay adjustment, graphic equalization, automation
Other note
Citation