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AssigneeU.S. Philips Corporation
InventorsNico V. Franssen, deceased, Friedrich J. de Haan, administrator, Adrianus J. M. Kaizer, Cornelis A. M. Wesche
Estimating the term…
A device for driving an electroacoustic transducer (1) comprising a feedback amplifier and a pickup (2) whose output signal is a measure of the acoustic output signal of the transducer. A by-pass network (4) bypasses at least the transducer and the pickup and produces an output signal that for frequencies outside the operating range of the transducer is large and for frequencies in the operating range (f.sub.1 to f.sub.h) of the transducer is small relative to the pickup output signal. The sum of the output signals of the pickup and the by-pass network serves as a feedback signal. This widens the transducer frequency range and reduces distortion. The device may include a limiter (11) and a network (5) before the transducer. The network has a frequency response inverse to that of the signal path from the electroacoustic transducer to the pickup to provide an additional reduction in the distortion.
A device for converting an electric signal into an acoustic signal comprising, an electroacoustic transducer, means for driving said electroacoustic transducer, a pick-up element for supplying an electric output signal which is a measure of the acoustic output signal of the transducer, a by-pass network which electrically bypasses at least the transducer and the pick-up element, a combination unit for combining the output signal of the pickup element and the output signal of the by-pass network, and a feedback circuit for feeding back to the transducer driving means the output signal of the combination unit as a negative feedback signal, characterized in that the by-pass network is adapted to produce an output signal which for frequencies within the operating frequency range of the transducer is small and for frequencies above and below the operating frequency range of the transducer is large relative to the output signal of the pickup element.
A sound reproduction system comprising a signal input terminal, an electroacoustic transducer, a signal path including a first combination unit and an amplifier connected in cascade between the input terminal and an input of the transducer, a pick-up device coupled to the transducer, a second combination unit having a first input coupled to an output of the pick-up device, a by-pass network having an output coupled to a second input of the second combination unit and coupled in circuit so as to electrically bypass at least the transducer and the pick-up device, said by-pass network deriving an output signal which for frequencies within the transducer frequency range is small and for frequencies above and below said transducer frequency range is large relative to the pick-up device output signal, and a negative feedback network coupling an output of the second combination unit to an input of the first combination unit.
Dependencies are inferred from the claim text.