Fu-Lin Shau

Publication Date

2000

Document Type

Dissertation/Thesis

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Electrical Engineering

LCSH

Equalizers (Electronics); Signal processing--Digital techniques

Abstract

This thesis proposes methods to design and synthesize audio equalizers with a practical equalizer order. In order to prevent the equalizers from boosting the signals in some frequency regions, we clip the peak portions of the equalizer’s amplitude response and re-synthesize the equalizer based on the artificial spectrum. In this research, four different techniques are used to synthesize the equalizer, but only two of them — the REMEZ equalizer and the FSF (Frequency Sampling Filtering) equalizer — have acceptable performance. The REMEZ equalizer is an FIR equalizer with linear phase, while the FSF equalizer is a structure of the HR filter bank. Both the REMEZ and the FSF equalizers can reduce the reverberation effect with a smaller equalizer order. A useful criterion — howling margin - is used to evaluate the equalizer’s performance and to calculate the optimum threshold for clipping the amplitude response of the original equalizer. In a real-time experiment, the REMEZ equalize, which is implemented on the Analog Device SHARC DSP board, is shown to have additional howling margin and to be able to reduce the reverberation effect in an auditorium.

Comments

Includes bibliographical references (pages [88])

Extent

x, 87, [1] pages

Language

eng

Publisher

Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

Media Type

Text

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