The Implementation of Time Selective Technique for Simulated Free-Field Measurements to Loudspeaker Characterization

The use of time selective techniques has been used for years in signal processing for acoustic, vibration and electro-acoustic to make simulated free-field measurements. Many acoustic solutions have been implemented and developed by specialized software companies and are offered to final users by the costs of large amounts of money. However, recent advances in hardware, software and data acquisition systems - allied to a good background in signal processing - has enabled the implementation of fast and practical solutions to more complex problems involving direct signal manipulations, analysis and post-processing. This work presents the home implementation of a test-bench solution used for loudspeaker quality evaluation that uses time selective techniques enabling measurement of free field response of loudspeakers to be performed without the need of an anechoic chamber, allowing the conduction of the measurement in a low cost test bench, inside an ordinary quiet room, without spent large facility investments. A case study is also presented showing the effectiveness and versatility of the implemented test bench.