Optimisation and motional feedback techniques in loudspeaker system design
Optimisation and motional feedback techniques in loudspeaker system design
A new synthesis method is described where the basic parameters of a loud speaker system are chosen using a numerical optimisation technique such that the error between some desired response of the system and the actual response is minimised. The method is illustrated with design examples for closed-box, vented-box and passive-radiator type loudspeaker systems. The computation of the displacement-limited power ratings of these systems taking into account the effects of the crossover network and the peak voltage spectrum of the input signal is described and illustrated. In cases where the desired response cannot be achieved in practice, there may be some benefit in applying motional feedback to the system at low frequencies. To enable prediction of the performance of such a system, general analytical expressions for the effective pass and efficiency and the power output of a loudspeaker system with motional feedback are developed. The design of an experimental motional feedback loudspeaker system using a microphone as the feedback transducer is described. The application of motional feedback at high frequencies is shown by calculation to give a reduction in the linear and non-linear distortions arising from breakup of the loudspeaker diaphragm.The practical problem of deriving a motional feedback signal which predicts the farfield sound-pressure response of the system at high frequencies is discussed. The feasibility of predicting the far field response of a flexible conical diaphragm from near field pressure measurements is investigated both theoretically and experimentally.
University of Southampton
1979
Adams, Glyn John
(1979)
Optimisation and motional feedback techniques in loudspeaker system design.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
A new synthesis method is described where the basic parameters of a loud speaker system are chosen using a numerical optimisation technique such that the error between some desired response of the system and the actual response is minimised. The method is illustrated with design examples for closed-box, vented-box and passive-radiator type loudspeaker systems. The computation of the displacement-limited power ratings of these systems taking into account the effects of the crossover network and the peak voltage spectrum of the input signal is described and illustrated. In cases where the desired response cannot be achieved in practice, there may be some benefit in applying motional feedback to the system at low frequencies. To enable prediction of the performance of such a system, general analytical expressions for the effective pass and efficiency and the power output of a loudspeaker system with motional feedback are developed. The design of an experimental motional feedback loudspeaker system using a microphone as the feedback transducer is described. The application of motional feedback at high frequencies is shown by calculation to give a reduction in the linear and non-linear distortions arising from breakup of the loudspeaker diaphragm.The practical problem of deriving a motional feedback signal which predicts the farfield sound-pressure response of the system at high frequencies is discussed. The feasibility of predicting the far field response of a flexible conical diaphragm from near field pressure measurements is investigated both theoretically and experimentally.
This record has no associated files available for download.
More information
Published date: 1979
Identifiers
Local EPrints ID: 462908
URI: http://eprints.soton.ac.uk/id/eprint/462908
PURE UUID: f2ed4316-6772-47d8-9c4a-dcc167911274
Catalogue record
Date deposited: 04 Jul 2022 20:22
Last modified: 04 Jul 2022 20:22
Export record
Contributors
Author:
Glyn John Adams
Download statistics
Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.
View more statistics