Journal Forum

Synchronized Swept-Sine: Theory, Application, and Implementation - October 2015

Effect of Microphone Number and Positioning on the Average of Frequency Responses in Cinema Calibration - October 2015
1 comment

The Measurement and Calibration of Sound Reproducing Systems - July 2015

Access Journal Forum

AES E-Library

A Study of Low-Frequency Near- and Far-Field Loudspeaker Behavior

Document Thumbnail

Low-frequency loudspeaker measurements are difficult. Room reflections, mediocre anechoic chambers, and random noise play havoc with the quest. Diffraction is different in nearfield and farfield. This paper covers a range of topics that bear on these problems, such as boundary element diffraction simulations, an approximate theory for low frequencies, methods to shorten the impulse response, and nearfield characteristics. A few points are illustrated with measurements. An earlier simplified diffraction theory of Kessel is checked for axisymmetric cylindrical and rectangular boxes by boundary-element simulations, in an attempt to pin down the diffractive 4pi>2pi transition. It turns out to have a strong connection to the acoustic centre of a loudspeaker. Some measurements are made under various conditions. Shortening methods are used to minimize the deleterious effect of truncating room reflections from the impulse response.

AES Convention: Paper Number:
Publication Date:

Click to purchase paper 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 $20 for non-members, $5 for AES members and is free for E-Library subscribers.

Learn more about the AES E-Library

E-Library Location:

Start a discussion about this paper!

Facebook   Twitter   LinkedIn   Google+   YouTube   RSS News Feeds  
AES - Audio Engineering Society