Abstract: An electro-acoustic transducer has a planar annular diaphragm suspended at both the inner and outer periphery. The transducer component is situated within the inner periphery and interacts with the diaphragm via outwardly extending connections.

Abstract: An amplifier system comprises a plurality of modules located within a cabinet in a manner providing minimum signal paths. The signal to be amplified is divided into frequency ranges for main amplification, and each main amplifier has an independent power supply. The modules are constructed from extrusions shaped and assembled to facilitate servicing and to function as heat sinks or as a cooling system as well as to provide mechanical protection and electrostatic shielding.

Abstract: A phonographic source has a turntable with a central hub joined by radial arms to a peripheral rim in which the weight of the turntable is concentrated so as to expose at least a major part of the underside of a record supported on the turntable. The record is supported at the hub, and by the arms and/or the rim, and in a modification by one or more concentric rings. The central spindle of the turntable for reception in the record center hole can be connected to the turntable drive shaft only indirectly, by a further construction in which the drive shaft connects with a lower turntable member connected with an upper turntable member for supporting the record by a concentric ring between the members. The source can include a pick-up arm having a counter-balance portion extending from the front position away from the portion carrying the cartridge, which counterbalance portion has at least approximately the shape of the other portion.

Abstract: An amplifier system comprises a plurality of modules located within a cabinet in a manner providing minimum signal paths. The signal to be amplified is divided into frequency ranges for main amplification, and each main amplifier has an independent power supply. The modules are constructed from extrusions shaped and assembled to facilitate servicing and to function as heat sinks or as a cooling system as well as to provide mechanical protection and electrostatic shielding.

Abstract: Electro-acoustic transducer arrangement are disclosed in which the tendency to diaphragm distortion between the drive and suspension positions is reduced and the efficiency as well as linear characteristics are improved especially at lower frequencies. A loudspeaker arrangement has an externally electrically driven transducer and one or more additional transducers pneumatically coupled therewith. Such additional transducer or transducers can be suspended in the same chassis as the electrically driven transducer. An additional transducer can be suspended in a separate chassis in the same enclosure as the electrically driven transducer or in a separate enclosure connected by an acoustic transmission line with that containing the electrically driven transducer. A pneumatically driven diaphragm can actuate an electromechanical transducer the output of which is used to drive another transducer and/or to modify or control its own movement and/or that of the diaphragm of the electrically driven transducer.