AES Dublin 2019
Paper Session P01
P01 - Loudspeakers: Part 1
Wednesday, March 20, 10:30 — 12:30 (Meeting Room 3)
Christof Faller, Illusonic GmbH - Uster, Zürich, Switzerland; EPFL - Lausanne, Switzerland
P01-1 Large Horns and Small Rooms – Do They “Play Nicely” Together?—Bjørn Kolbrek, Celestion - Ipswich, UK
For some audiophiles, having a huge, low-cutoff bass horn built into the wall of the listening room represents the ultimate low frequency solution. Without considering the practicalities of such an installation, this paper will look at the performance of low frequency horns mounted in the wall of a small room compared to the performance of a typical point source closed box type sub-woofer and an array of such sub-woofers. Simulation results indicate that in addition to higher efficiency, the horns provide smoother response in the listening position and less seat-to-seat variation.
Convention Paper 10132 (Purchase now)
P01-2 Predistortion Technique for Generating Spectrally Clean Excitation Signals for Audio and Electro-Acoustic Nonlinear Measurements—Antonin Novak, Université du Mans - Le Mans, France; Laurent Simon, Le Mans Université - Le Mans, France; Pierrick Lotton, Le Mans Cedex 9, France; Manuel Melon, Le Mans Université - Le Mans cedex 9, France
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.
Convention Paper 10133 (Purchase now)
P01-3 Sensory Profiling of High-End Loudspeakers Using Rapid Methods—Part 4: Flash Profile with Expert Assessors—Irene Arrieta Sagredo, Bang & Olufsen - Struer, Denmark; Samuel Moulin, Bang & Olufsen - Struer, Denmark; Søren Bech, Bang & Olufsen a/s - Struer, Denmark; Aalborg University - Aalborg, Denmark
This study is the fourth in a series of papers investigating different rapid sensory profiling methods applied to audio stimuli [1, 2, 3]. In particular, this paper considers Flash Profile, a verbal-based method that allows assessors to use their own vocabulary, for perceptual audio evaluation. A listening test was conducted with expert listeners investigating the ability of Flash Profile to describe and discriminate five sets of high-end loudspeakers. The influence of using different audio-stimuli in order to get a broader perceptual image is supported by doing a track by track analysis, using Multiple Factor Analysis [4, 5]. The results suggest that the differences between loudspeakers lie in two main dimensions related to the timbral and spatial characteristics of the stimuli. Flash Profile seem to be a time-efficient tool for visualization and reduction of perceptual dimensions, being useful for the description and discrimination of a set of audio stimuli with medium to small audible differences.
Convention Paper 10134 (Purchase now)
P01-4 Poster Introductions 1—N/A
The purpose of Poster Introductions at the end of certain paper sessions is to give the poster authors a chance to briefly outline what is in their paper and encourage people to come to their poster session and ask questions. • Optimized Exciter Positioning Based on Acoustic Power of a Flat Panel Loudspeaker—Benjamin Zenker; Shanavaz Sanjay Abdul Rawoof; Sebastian Merchel; Ercan Altinsoy • Practical Problems in Building Parametric Loudspeakers with Ultrasonic Piezoelectric Emitters—Antonin Novak; Jose Miguel Cadavid Tobon • Time Stretching of Musical Instrument Tones—Sean O’Leary