Publications associées à Experimental assessment of low-frequency electroacoustic absorbers for room modal equalization in actual listening rooms

PID-like active impedance control for electroacoustic resonators to design tunable single-degree-of-freedom sound absorbers

Sound absorption at low frequencies still remains a challenge in both scientific research and engineering practice. Natural porous materials are ineffective in this frequency range, as well as acoustic resonators which present too narrow bandwidth of absor ...

2022

Sound Field Reconstruction in a room through Sparse Recovery and its application in Room Modal Equalization

Vu Thach Pham

The acoustics of a room often refer to the quality of the room in terms of sound recording as well as sound reproduction. At low frequencies, where the wavelengths are of the same order of magnitude with the dimensions of the room, due to the standing wave ...

EPFL2021

Numerical investigation of optimal divertor gas baffle closure on TCV

Holger Reimerdes, Stefano Coda, Benoît Labit, Christian Gabriel Theiler, Mirko Wensing, Davide Galassi

A first set of divertor gas baffles has recently been installed in the TCV tokamak. In order to explore the physics determining the benefits and limitations of divertor baffling and to guide the design of a possible second generation of baffles, the effect ...

2020

Duct modes damping through an adjustable electroacoustic liner under grazing incidence

Hervé Lissek, Romain Boulandet, Gaël Matten

This paper deals with active sound attenuation in lined ducts with flow and its application to duct modes damping in aircraft engine nacelles. It presents an active lining concept based on an arrangement of electroacoustic absorbers flush mounted in the du ...

2018

On the Optimisation of Multi-Degree-of-Freedom Acoustic Impedances of Low-Frequency Electroacoustic Absorbers for Room Modal Equalisation

Hervé Lissek, Etienne Thierry Jean-Luc Rivet, Sami Driss Karkar

Low-frequency electroacoustic absorbers have recently been developed as a solution for the modal equalisation. Firstly investigated in waveguides, the technique consists in matching the acoustic impedance at a closed-box loudspeaker diaphragm to the charac ...

2017

Sensorless Electroacoustic Absorbers Through Synthesized Impedance Control for Damping Low-Frequency Modes in Cavities

Hervé Lissek, Romain Boulandet, Etienne Thierry Jean-Luc Rivet

This paper presents a concept of sensorless electroacoustic absorber for damping the low-frequency modes in a cavity such as a duct or a room. Taking advantage of the reciprocity of the voice coil transducer, it is shown that a synthetic electrical admitta ...

S Hirzel Verlag2016

Through the Hourglass: A Faithful Audiovisual Reconstruction of the Old Montreux Casino

Martin Vetterli

In architecture, space is traditionally understood as a cumulus of forms, colors and textures that form a conceived area, or-in other words-architectural space design is mainly achieved by following visual concepts. The human experience of space, however, ...

Springer2015

Analysis and Design of Mobile Device Antenna-Speaker Integration for Optimum Over-the-Air Performance

Juan Ramon Mosig, Nicolas Chavannes

In this paper, the mutual coupling between a mobile device antenna and a closely integrated miniature moving-coil speaker is investigated. The analysis focuses on the speaker radio-frequency harmonic resonance characteristics and the antenna radiation effi ...

Institute of Electrical and Electronics Engineers2015

Development of electroacoustic absorbers as soundproofing solutions for industrial ventilation systems

Victor Desarnaulds, Hervé Lissek, Etienne Thierry Jean-Luc Rivet

In many industrial environments, room and cavity modes may severely strengthen the annoyance of low frequency noises, such as in ventilation equipments. Moreover, there is an obvious technological gap in the state-of-the-art relative to low-frequency sound ...

2013

Assessment of active electroacoustic absorbers as low-frequency modal dampers in rooms

Hervé Lissek, Romain Boulandet, Iris Rigas, Etienne Thierry Jean-Luc Rivet

In small to medium size rooms, natural room modes may severely strengthen the annoyance of low frequency noises, such as traffic or equipment noise. Moreover, there is an actual technological gap in the state-of-the-art concerning low-frequency treatments, ...

2012

Modal numerical-experimental identification method for characterising the elastic and damping properties in sandwich structures with a relatively stiff core

Thomas Gmür, Jeannot Frieden, Michaël Schwaar

In this paper, a mixed numerical-experimental identification procedure for characterising the storage and loss properties in sandwich structures with a relatively stiff core is developed. At the computational level, the proposed method is based upon an ori ...

2012

Study on room modal equalization at low frequencies with electroacoustic absorbers

Hervé Lissek, Romain Boulandet, Iris Rigas, Etienne Thierry Jean-Luc Rivet

Nowadays, requirements for acoustic treatments in rooms are ever more demanding in terms of performance and compactness. A recurring issue in closed spaces is the occurrence of standing waves and acoustic interferences at low frequencies. These unwanted ph ...

2012

Advanced control for modifying the acoustic impedance at the diaphragm of a loudspeaker

Hervé Lissek, Romain Boulandet, Etienne Thierry Jean-Luc Rivet

The control of low-frequency sound fields can be addressed efficiently through acoustic impedance matching. Basically, the diaphragm of electroacoustic transducers are used as refracting surface that controls the reaction of the boundaries in any surroundi ...

2012

Spatial Acoustic Signal Processing

Mihailo Kolundzija

A sound field on a line or in a plane has an effectively limited spatial bandwidth determined by the temporal frequency. Similar can be said for sound fields from far-field sources when analyzed on circular and spherical apertures. Namely, for a given freq ...

EPFL2012

Acoustic impedance synthesis at the diaphragm of moving coil loudspeakers using output feedback control

Hervé Lissek, Romain Boulandet

This paper discusses a time-domain technique for synthesizing acoustic impedance at the diaphragm of a loudspeaker using a proportional-plus-derivative output feedback. The dynamics of electroacoustic transducers such as moving-coil loudspeakers can be rea ...

2011

Dynamic Measurement of Room Impulse Responses using a Moving Microphone

Martin Vetterli, Luciano Sbaiz, Thibaut Ajdler

A novel technique for the recording of large sets of room impulse responses or head-related transfer functions is presented. The technique uses a microphone or a loudspeaker moving with constant speed. Given a setup (e.g. length of the room impulse respons ...

2007

Spatio-temporal analysis of spontaneous speech with microphone arrays

Guillaume Lathoud

Accurate detection, localization and tracking of multiple moving speakers permits a wide spectrum of applications. Techniques are required that are versatile, robust to environmental variations, and not constraining for non-technical end-users. Based on di ...

EPFL2007