A critical investigation into the properties of metallised film capacitors for high quality sound reproduction

This is an account of work carried out through a Knowledge Transfer Partnership withIndustrial Capacitors (Wrexham) Ltd to assess the effects of metallised filmpolypropylene capacitors on key sonic attributes of reproduced sound. The capacitorsunder investigation were found to be electrically identical whilst exhibiting differinglevels of mechanical resonance within the audio frequency band. Results obtainedfrom subjective listening tests have shown this to have a measurable effect on audiodelivery.The listening test methodology employed in this study evolved from initial ABX typetests with set program material to the final A/B tests where trained test subjects usedprogram material that they were familiar with. The main findings are that capacitorsused in crossover circuitry can exhibit mechanical resonance and that maximizing thelistener's control over the listening situation and minimizing stress to the listener werenecessary to obtain meaningful subjective test results.The main findings are that capacitors used in crossover circuitry can exhibitmechanical resonance and this resonance was identified to have a negative effect onreproduced sound in controlled subjective listening tests. In addition, newmeasurement techniques have been developed that could be used to identify lowresonance capacitors during production and, hence, select capacitors that were likelyto have superior reproduction quality without the need for further listening tests.

Level dc:type.qualificationlevel

Master's Level (Level 7)

Year dc:date.issued

2009

Author dc:creator

• Dodds, PS

Language dc:language

en

Identifier

oai:salford-repository.worktribe.com:1337195

OAI identifier oai:identifier

oai:salford-repository.worktribe.com:1337195