AES E-Library

AES E-Library

Predistortion Technique for Generating Spectrally Clean Excitation Signals for Audio and Electro-Acoustic Nonlinear Measurements

In many audio and electro-acoustic nonlinear measurements we need to excite the nonlinear system under test with an excitation device that is not linear. A typical example is the study of the nonlinear behavior of a loudspeaker mechanical part, where the mechanical part (the nonlinear system under test) is excited externally, either with a shaker or pneumatically using another loudspeaker. We often consider that the excitation device is linear, which is unfortunately not correct. In this paper we present a simple method that corrects the distorted output signal of the excitation device by pre-distorting the input signal. The process is based on harmonic injection and can be applied to any periodic signal that is used for the measurement, e.g., a sine wave to measure the total harmonic distortion (THD), a two-tone signal to measure an intermodulation distortion (IMD), or a multi-tone signal. The experimental results provided on an electrodynamic loudspeaker show that the undesired spectral components of the acoustic pressure inside the sealed box can be suppressed to the level of the background noise.

Authors:
Affiliations:
AES Convention: Paper Number:
Publication Date:
Subject:
Permalink: http://www.aes.org/e-lib/browse.cfm?elib=20266

Click to purchase paper as a non-member or login as an AES member. If your company or school subscribes to the E-Library then switch to the institutional version. If you are not an AES member and would like to subscribe to the E-Library then Join the AES!

This paper costs $33 for non-members and is free for AES members and E-Library subscribers.

Learn more about the AES E-Library

E-Library Location:

Start a discussion about this paper!


AES - Audio Engineering Society