Abstract: In a bass-reflex enclosure or cabinet of the kind in which a loudspeaker unit is mounted in an opening (11) of a front plate (10) and at the end of two coaxially mounted and into the interior of the cabinet extending tubular members (13, 14), so that an annular slot (28) around the speaker unit (16) is provided and in a known manner utilized as a bass-reflex port arranged coaxially with the speaker unit (16), said speaker unit is fixedly mounted on the one end of the inner tube (14) whereas the other outer tube (13) is fixedly mounted to the front plate (10) or forms an integral part therewith. The assembly comprising the inner tube (13) having the speaker unit (16) mounted thereto is suspended to the front plate (10) by means of a number of vibration absorbing rubber blocks (22) which are evenly distributed along the periphery of the speaker. Thereby an acoustically dead front plate (10) is achieved.

Abstract: An improved electrodynamic acoustic transducer with a slotted piston suspension system which results in greater linear excursions by relieving stresses within the diaphragm during the movement and allows improved operations of transducer with greater magnet size and greater radiating areas of diaphragm suspension. Overall efficiency of transducer is thereby improved. An improved piston suspension can be utilized with electrodynamic acoustic transducers operating in the range of 200 to 20,000 cycles per second.

Abstract: The electro-acoustical transducer comprises a membrane flexible or rigid before assembling, the front portion of which has an aperture with a half-angle .alpha.. In order to obtain sound waves in phase at any listening point, the front portion is the site of vibrations which are responsible for sound emission and are transmitted in the membrane material with a velocity V.sub.m approximating V.sub.0 /cos .alpha., where V.sub.0 is the velocity of sound in air. The membrane is rigidly attached to the transducer chassis and is tensioned under a tensile stress between 5 and 20 KN, in order to the vibrations be bending transverse waves, the vibrational energy of which is totally transferred to air in form of sound waves before reaching the larger end of the membrane. The mechanical-acoustical output is close to unity and the overall energy output lies between 50 and 80%. The displacement of the rear portion of the membrane into airgap of motor is in the macro-deformation field.

Abstract: An electronic component, such as a speaker, is supported on the chassis of an electronic device, such as a small radio pager, by a resilient annular member which is latched to the chassis. The annular member has an inner surface for receiving a part of the component, such as the speaker pot, and a plurality of fingers extending from the member and inserted through an opening in the chassis with outwardly extending hook-like ends which engage the opposite side of the chassis. The member and fingers are flexible for mounting on the chassis, and are rendered more rigid when the component is inserted therein so that the fingers hold the member on the chassis. The annular member may include portions which are flexed when the component is placed therein to store energy which tends to move the component out of the member. When used for supporting a speaker, the member tends to move the speaker pot to hold the speaker edge against a grill which may be formed in the housing of the device.

Abstract: Provided is an electro-dynamic speaker having a unique damper extending between a coil bobbin carried by the inner periphery of a diaphragm and a frame carrying the outer periphery of the diaphragm. Due to the provision of the unique damper, a satisfactory compliance along the axis of the bobbin and a favorable regulating force against radial deforming force are obtained, to ensure a good linearility of the force-displacement characteristics of the speaker in the low frequency range even during vibration at a large amplitude.

Abstract: An electroacoustic transducer having a diaphragm apparatus. The diaphragm apparatus has an annular diaphragm and a pair of outer and inner edges respectively conjoining with the outside and the inside of the diaphragm. Both edges have sets of pleats arranged continuously along the circumferential directions of the diaphragm but directed in opposite directions to each other. Each pleat, at least in the outer edge, comprises a bottom line extending from a boundary between the outer fixing area and the outer edge to a boundary between the outer edge and the diaphragm wherein an arc defined by the point of intersection of the inner end of the bottom line of any pleat in the outer edge and the second boundary and the point of tangency on the second boundary of a line through the point of intersection of the outer end of the same bottom line and the first boundary subtends a central single .theta..sub.0 and the position of the former point of intersection is given by the relation; ##EQU1## where .theta..sub.

Abstract: An improved speaker mounting for an electronic guitar is provided. The mounting includes a rubber cup extending into the interior of the guitar from a cut out in the top board surface of the guitar. The cup has a flanged rim extending about the opening and a grove formed below the flange. A speaker is disposed within the cup and has portions captured in position by the grove. A cap is positioned over the cut out and screw means extend through the cap and cup flange into the guitar top surface securing the cap and flange to the top surface.

Abstract: An improved sound reproducing device which includes a housing, an acoustic diaphragm and drive means for driving the acoustic diaphragm. Corrugated compliant coupling means is provided for supporting the acoustic diaphragm with respect to the housing in a predetermined lateral position for longitudinal movement relative thereto. The compliant coupling means has a lateral cross-sectional shape which is noncircular so that the acoustic diaphragm is centered in a predetermined lateral position but which allows freedom of movement in the longitudinal direction. The drive means provides the relative longitudinal movement between the acoustic diaphragm and the housing. In a preferred embodiment, the corrugated compliant coupling has a rectangular cross-sectional shape.

Abstract: Mounting of a substantially planar diaphragm defining a sound transducer, having a central portion surrounded by stepwise interconnected outer plates to assure correctly guided vibratory movement of the central portion. Recesses in the central portion opening into the front face thereof, housing and supporting therein tweeters, the sound emission axes of which may be so oriented that they converge towards the rear face of the central portion.

Abstract: The present invention is directed to an apparatus for reproducing the bass components of an audio signal with a high degree of accuracy and minimal distortion, utilizing an enclosure of relatively small size. The apparatus comprises a substantially sealed enclosure in combination with a radiating diaphragm driven by an electromagnetic transducer, the principal diaphragm restoring forces being the elastic forces exerted against the diaphragm surfaces by the gaseous medium engaging such surfaces.

Abstract: In a loudspeaker, the diaphragm is connected to the edge member fixedly secured to the frame through an intermediate supporting means, at least one part of the intermediate supporting means is made of a material having a low hysteresis characteristic. According to another aspect of the invention, the construction of a loudspeaker is such that the diaphragm supporting means is separated from the airtight means of the diaphragm, so that the loudspeaker can operate in response to even a small signal with high fidelity.

Abstract: A drone acoustical transducer for a loudspeaker system has an improved means of interconnecting the generally conical speaker diaphragm and supporting basket. In conventional fashion, the acoustical transducer includes a generally conical speaker diaphragm supported within a vented basket having an open front and a rear wall. The large, front end of the diaphragm is flexibly connected to the front of the basket by means of a supple annulus. The basket has a rear wall having an upstanding boss which is coaxial with the diaphragm and smaller in diameter than the small end of the diaphragm. A flexible spider interconnects the small end of the diaphragm with the boss, allowing full excursion of the vibrating speaker diaphragm. To allow for maximum excursion of the diaphragm, the rear wall of the basket may be concave as viewed from the rear.

Abstract: A diaphragm for a moving evil loudspeaker is formed of a material which has a mechanical "0"value of from 7 to 12, a Youngs modulus of from 8.5 to 17.5 .times. 10.sup.5 KN/M.sup.2 and a density of from 0.85 to 1.05 g/cc. The diaphragm forming material is preferably formed of polypropylene or a propylene-containing copolymer. The diaphragm may be of cone or dome type and included are moving coil loudspeaker constructions wherein other vibrating elements, particularly spiders and outer cone support rings, are formed of the same type of material as the diaphragm.

Abstract: A loudspeaker having a diaphragm including first and second layers and a core sandwiched between the layers, the core being firmly secured to the inner surface of each layer so as to form a unitary structure therewith, a drive assembly causes the diaphragm to vibrate in accordance with a varying electrical input signal fed thereto, and a support is provided for supporting the diaphragm and drive assembly. The layers are formed of materials through which the velocity of propagation of a longitudinal wave is greater than 5000 m/sec, and the core is formed of materials having a shearing elastic modulus Gco which exceeds the value ##EQU1## WHERE E.sub.f is the longitudinal elasticity of each of the layers,t.sub.f is the thickness of each of the layers,t.sub.c is the thickness of the core, andl is the length across the surface of the diaphragm.

Abstract: A loudspeaker comprises a frame, a cone assembly which includes a cone body having an outer periphery spaced away from the frame, and a flexible annular surround connecting the periphery of the cone body to the frame. The surround has an inner peripheral flange secured to the outer periphery of the cone body, an outer peripheral flange secured to the frame, and an arched web between the two flanges and spanning the gap between the cone body and the frame. The radial cross-section of the arched web has a varying radius of curvature with a greater radius at the bases thereof than at the apex. The preferred cross-sectional configuration is a parabola. The arched web decreases in thickness from the bases thereof toward the apex so that the minimum thickness is located at the apex of the arch and the maximum thickness is located at the bases of the arch. The surround is made of a solid resilient material having a durometer of less than about 55, preferably a rubber such as butyl.

Abstract: A very small audio speaker is described which has a broad-band electrical-mechanical transducer, a broad-band mechanical-air-transducer, and a special suspension system which combine to produce a substantially flat frequency response over substantially the entire audio range from about 50 Hz to about 18,000 Hz.The broad-band electrical-mechanical transducer has either a voice coil with two axially spaced subsections, or a magnetic field with two axially spaced subsections, with the other being continuous between two effective boundaries. Each subsection of the coil, for example, is generally centered on the boundary of the magnetic flux field so that as one subsection moves into the flux field, the other subsection moves out of the flux field at the same rate, thus maintaining a linear force as the coil reciprocates through a much longer distance than is possible using conventional continuous coil and magnetic structures.

Abstract: An acoustic material suitable for use as a speaker edge comprises an expanded plastic and minute collagen fibers wherein the content of the collagen fibers is 15 - 40% based on the weight of the expanded plastic and the length of the fibers is equal to or less than 1 mm.