Sound reproduction device with active noise compensation

US5809156A · kind A · utility

Assignee

• Sennheiser electronic GmbH & Co. KG · DE

Inventors

• Volker Bartels · Düsseldorf, DE
• Burkhard Markmann · Großburgwedel, DE

Key dates

• Filing date: Nov 20, 1995
• Grant date: Sep 15, 1998
• Expiry date: Nov 20, 2015

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04R3/00
• WIPO field: Audio-visual technology
• WIPO sector: Electrical engineering

Abstract

A sound reproduction device such as a headphone with active noise compensation has a housing and a transducer for converting electrical signals to sound waves is disposed within the housing. The transducer has a diaphragm for separating the volume (V.sub.2) in front of the diaphragm from the volume (V.sub.1) to the rear of the diaphragm. The transducer diaphragm and rear volume (V.sub.1) have a determined compliance. The sound reproduction device includes active noise compensation components for reducing unwanted noise at the output of the transducer. The diaphragm has a compliance (N.sub.M) which is less than the compliance (N.sub.1) of the rear volume (V.sub.1). The diaphragm is preferably constructed from a plurality of layers. In a further preferred arrangement, a damping element is disposed very close to the rear side of the diaphragm. A preferred construction for optimizing the voice coil is described. In an active noise compensation construction employing a microphone having a central axis for picking up noise, a preferred arrangement orients the central microphone axis at an angle of about 45.degree. relative to the central axis of the transducer.