Details

Autor(en) / Beteiligte

• Lissek, Hervé
• Boulandet, Romain
• Fleury, Romain

Titel

Electroacoustic absorbers: Bridging the gap between shunt loudspeakers and active sound absorption

Ist Teil von

• The Journal of the Acoustical Society of America, 2011-05, Vol.129 (5), p.2968-2978

Ort / Verlag

Melville, NY: Acoustical Society of America

Erscheinungsjahr

2011

Link zum Volltext

Quelle

AIP Journals

Beschreibungen/Notizen

• The acoustic impedance at the diaphragm of an electroacoustic transducer can be varied using a range of basic electrical control strategies, amongst which are electrical shunt circuits. These passive shunt techniques are compared to active acoustic feedback techniques for controlling the acoustic impedance of an electroacoustic transducer. The formulation of feedback-based acoustic impedance control reveals formal analogies with shunt strategies, and highlights an original method for synthesizing electric networks ("shunts") with positive or negative components, bridging the gap between passive and active acoustic impedance control. This paper describes the theory unifying all these passive and active acoustic impedance control strategies, introducing the concept of electroacoustic absorbers. The equivalence between shunts and active control is first formalized through the introduction of a one-degree-of-freedom acoustic resonator accounting for both electric shunts and acoustic feedbacks. Conversely, electric networks mimicking the performances of active feedback techniques are introduced, identifying shunts with active impedance control. Simulated acoustic performances are presented, with an emphasis on formal analogies between the different control techniques. Examples of electric shunts are proposed for active sound absorption. Experimental assessments are then presented, and the paper concludes with a general discussion on the concept and potential improvements.