Automotive audio system transducer
A signal processing method and Automotive Audio System 290 comprising a tripolar loudspeaker configuration housed in at least one automotive head-rest assembly 200 or 500 , whose radiation pattern, in conjunction with inter-element delays and other design features, is such that that passengers are afforded temporal and amplitude cues for achieving the desired soundfield appropriate for a variety of audio program material. Optionally, some or all of the headrest assembly transducers are aligned and configured with a Floating Waveguide member 470.
1. An automotive audio system electrodynamic acoustic transducer, comprising:
a pole piece having a first end terminating distally in a distal end surface;
a voice coil comprising wire windings configured to receive electrical current, the voice coil being configured to move along the first end of the pole piece;
a magnetic structure comprising parts defining an air gap in which the voice coil is disposed, the magnetic structure being configured to create a magnetic field in which the voice coil is configured to move along the first end of the pole piece;
a diaphragm comprising a central portion with an inner periphery and an outer periphery, the inner periphery of said diaphragm defining a central opening and being attached to the voice coil to move with the voice coil;
a floating or suspended bulbous waveguide member spaced from and suspended before the distal end surface of the pole piece, the waveguide member having a circumference that projects radially to a larger diameter than the pole piece to project laterally over an inner radiating area of the diaphragm;
an acoustically transparent mesh or grill structure that supports the waveguide member in an orientation which is centered along a central aiming or excursion axis of the automotive audio system electrodynamic acoustic transducer;
wherein the waveguide member has a proximal smaller diameter circular surface separated by a waveguide member axial thickness from a distal smaller diameter circular surface, with a central larger diameter central segment defining a larger diameter peripheral edge that is integrally molded with or mounted to the acoustically transparent mesh or grill structure;
wherein the waveguide member is suspended apart from the distal end surface of the pole piece to provide a gap or cavity defined by a volume of air in front of the distal end surface of the pole piece;
wherein the distal end surface of the pole piece is covered or occluded; and
wherein the automotive audio system transducer is configured such that, in operation, a substantial portion of sound within the gap or cavity is absorbed and attenuated to reduce destructive interference.
2. An automotive audio system electrodynamic acoustic transducer comprising:
a pole piece having a first end terminating distally in a distal end surface;
a voice coil comprising wire windings configured to receive electrical current, the voice coil being configured to move along the first end of the pole piece;
a magnetic structure comprising parts defining an air gap, wherein the voice coil is disposed in the air gap so that the magnetic structure is configured to create a magnetic field in which the voice coil is configured to move along the first end of the pole piece;
a diaphragm comprising a central portion with an inner periphery defining a central opening and an outer periphery, the inner periphery of the diaphragm being attached to the voice coil to move with the voice coil;
a floating or suspended bulbous waveguide member spaced from and suspended apart from the distal end surface of the pole piece, the waveguide member having a circumference that projects radially to a larger diameter than the pole piece to project laterally over an inner radiating area of the diaphragm;
a mesh or grill structure configured to cause the waveguide member to float within and be supported in an orientation which is centered along a central aiming or excursion axis of the automotive audio system electrodynamic acoustic transducer;
wherein the waveguide member has a proximal smaller diameter circular surface separated by a waveguide member axial thickness from a distal smaller diameter circular surface, with a central larger diameter central segment defining a larger diameter peripheral edge;
wherein the mesh or grill structure suspends the waveguide member apart from the distal end surface of the pole piece to provide a gap or cavity defined by a volume of air between the waveguide member and the distal end surface of the pole piece;
wherein the distal end surface of the pole piece is covered or occluded; and
wherein the automotive audio system transducer is configured such that, in operation, a substantial portion of sound within gap or cavity is absorbed and attenuated to reduce destructive interference.
3. An automotive audio system electrodynamic acoustic transducer comprising:
a pole piece having a first end terminating distally in a distal end surface;
a voice coil comprising wire windings configured to receive electrical current, the voice coil being configured to move along the first end of the pole piece;
a magnetic structure comprising parts defining an air gap, wherein the voice coil is disposed in the air gap so that the magnetic structure is configured to create a magnetic field in which the voice coil is configured to move along the first end of the pole piece;
a diaphragm comprising a central portion with an inner periphery defining a central opening and an outer periphery, the inner periphery of the diaphragm being attached to the voice coil to move with the voice coil;
a waveguide member spaced from and suspended before the distal end surface of the pole piece, said waveguide member having a circumference that projects radially to a larger diameter than the pole piece to project laterally over an inner radiating area of the diaphragm;
a mesh or grill structure configured to cause the waveguide member to float within and be supported in an orientation which is centered along a central aiming or excursion axis of the automotive audio system electrodynamic acoustic transducer;
wherein the waveguide member has a proximal smaller diameter circular surface separated by a waveguide member axial thickness from a distal smaller diameter circular surface, with a central larger diameter central segment defining a larger diameter peripheral edge;
wherein the mesh or grill structure suspends the waveguide member apart from the distal end surface of the pole piece to provide a gap or cavity defined by a volume of air between the waveguide member and the distal end surface of the pole piece;
wherein the distal end surface of the pole piece is covered or occluded; and
wherein the automotive audio system transducer is configured such that, in operation, a substantial portion of sound within gap or cavity is absorbed and attenuated to reduce destructive interference.