Automatic Equalization using handclaps as Impulse for acoustic room measurements

Student thesis: Master's Thesis

Abstract

he acoustical properties of listening rooms have a major impact on the way sound behaves in a room. If music is played with exactly the same receiver, amplifier and speakers but the room is changed, the perceived sound will be different. It would therefore be interesting to find a way to measure this influence, and to negate these changes with an equalizer. In this thesis, the emphasis lies on the notion of user interaction. The goal is to make the user (customer) an important factor in the measurement procedure. Claps were chosen as impulses, as this requires no extra needed equipment, and possesses relatively good properties, which makes it a viable option for impulse response measurements.
Most impulse response measurements use impulses with the speakers as sources. If the results are used for equalization, the frequency response of the speakers is also taken into account. This can be non-desirable, since speakers can have a special characteristic sound that would be removed.
In this thesis, an analysis on the clap as an impulse source is performed. The results indicate that for frequencies above 315 Hz the results are very usable and comparable to results obtained with industry standard software and hardware. Below those frequencies, large discrepancies can be observed. A theory is presented on how to extract usable information from the low frequencies using a correction curve, based on the differences between the imperfect clap- based impulse response and the standard response. This is validated by analyzing the reverberation times for both the claps and the standardized measurements.
Date of Award9 Sep 2013
Original languageEnglish
SupervisorAbdellah Touhafi (Promotor), Felipe Reinoso Carvalho (Jury), Kris Steenhaut (Jury), Bruno Tiago da Silva Gomes (Jury), Felipe Reinoso Carvalho (Advisor) & Jelmer Tiete (Advisor)

Keywords

  • acoustics
  • signal processing
  • room acoustics

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