A plurality of nodes of split vibration of a diaphragm are driven by a plurality of voice coils to prevent split vibration of the diaphragm. The voice coils are inserted between three or more layers of magnetic poles respectively and driven by a magnetic circuit including a plurality of magnets magnetized in the same direction as the vibration of the voice coils.
A system for providing the effect of an extended soundstage comprises a pair of stereophonic loudspeakers, each having a movable or vibrational element driven by a pair of voice coils including a principal or main voice coil and an auxiliary or enhancement voice coil. The principal voice coil of each speaker is driven in a customary manner from one channel of a stereophonic amplifier, while the enhancement voice coil is driven in a reversed phase sense from the output of the opposite channel, and sound is effectively provided over an extended apparent source having dimensions beyond the spacing between the loudspeakers.
Loudspeaker improvements are disclosed to add versatility and economy, particularly for multimedia applications. These improvements include: (1) the printing of voice coil conductors, (2) adding conductive elements to the sound driver surface, (3) using multiple coil paths around a single voice coil former to drive the overall sound driver surface, (4) creating a simple digital loudspeaker with multiple coil paths, (5) implementing multiple functions in the multiple coil loudspeaker/transducer, (6) creating integrated systems with a series of multiple function, multiple coil loudspeakers/transducers and (7) providing a novel subwoofer loudspeaker housed in a cylinder.
A speaker unit having a pair of voice coils each wound around a common coil bobbin and a first magnet for driving one coil of the pair of voice coils. A second magnet is provided for suppressing flux leakage of the first magnet and driving one coil of the pair of voice coils.
A loudspeaker is provided including a diaphragm having a lower end formed with an inner surface mounted to the voice coil former, an outer surface spaced from the inner surface and a number of circumferentially-spaced vent bores formed between the inner and outer surfaces which vent a dust cap cavity. Alternatively, the lower end of the diaphragm is mounted to the outer surface of the voice coil in position so that a deflector formed in such lower end is located in the path of a flow of air entering and leaving the dust cap cavity through vent bores formed in the voice coil former to direct such air flow over the wire winding of the voice coil and obtain at least some cooling thereof in addition to venting the dust cap cavity.
A loudspeaker is disclosed having a pole piece formed with at least one axial bore, and at least one vent bore extending between the outer surface of the pole piece and intersecting the axial bore at a location where the voice coil of the loudspeaker is concentrically disposed about the pole piece. The at least one axial bore and at least one vent bore are effective to cause the flow of cooling air, which enters and exits the dust cap cavity from outside of the speaker, to flow directly against at least a portion of the interior of the former of the voice coil.
