Ilias Liosatos - Réverbération à convolution

Création d’une base de données de ‘IR’ (Réponse Impulsionnelle) – Implication en réverbération à convolution

Travail de mémoire de fin d’études : Ce travail traite la simulation de l’acoustique de divers bâtiments d’importance architecturale et culturelle sur l’île de Céphalonie en Grèce. La création d’une base de données d’archives audio a été effectuée, au sein d’utilisation pour de 'plug-ins' de traitement des enregistrements sonores en environnement studio.

La méthode ESS (Exponential Sine Sweep) et les techniques de prise de son ‘Blumlein’ et ‘AB’ ont été utilisés pour la réalisation du projet

TECHNOLOGICAL EDUCATION INSTITUTE OF IONIAN ISLANDS
DEPARTMENT OF SOUND AND MUSICAL INSTRUMENT TECHNOLOGY

CREATION OF IMPULSE RESPONSES’ LIBRARY – IMPLEMENTATION IN CONVOLUTION REVERB

DISSERTATION REPORT
LIOSATOS ILIAS

Lixouri, Kefalonia 2013

Abstract

    This work focus in the procedure needed for the creation of an Impulse Responses’ library from specific buildings at the island of Kefalonia and its use in convolution reverb. The terms of δ-Dirac function and convolution are defined, as well as the properties of reverberation and the use of convolution reverb are described. Furthermore the theoretical background to the methods suitable for capturing IR’s is given in reference to the related bibliography.
    Such an IR’s library is based on the measurement of the impulse response of a space, which is either but the Fourier transform of the space’s frequency response to an excitation signal reproduced in it.
    The best method so far proposed by Angelo Farina in 2000 is the Exponential Sine Sweep also known as ESS, providing better dynamic range and signal to noise ratio against traditional methods such as transient method, MLS (Maximum Length Sequence) and LSS (Linear Sine Sweep). Furthermore it allows the separated measurement of harmonic distortions caused by the sound equipment.
    Despite the success of ESS method adopted for this work’s purposes, the measured IRs are not suitable for professional use in convolution reverb plug-ins, of course without of excluding the creative point of view. The facts that led to these unsuitable results are analyzed as an example to avoid in similar works and as a motivation to further researches.

Keywords: Impulse Response, convolution, deconvolution, MLS, sinesweep, LSS, ESS