|
PAPERS |
|
On the Design and Efficiency of Class A, B, AB, G, and H Audio Power Amplifier Output Stages
(PDF-670K) |
|
|
Rosalfonso Bortoni, Sidnei Noceti Filho, and Rui Seara |
547 |
|
Audio power amplifiers are usually analyzed with resistive loads with an
added compensation factor for nominally reactive loads of real
loudspeakers. The current study examines amplifiers of class A, B, AB,
G, and H under conditions of reactive loads with sine wave to determine
the true stress on the power stage. By using a more exact method, the
economic inefficiency of the older approximation is avoided. A procedure
for designing and assessing output stages is also proposed. |
|
|
Comment on this paper
|
|
| |
|
Requirements for Low-Frequency Sound Reproduction, Part I: The Audibility of Changes in Passband Amplitude Ripple and Lower System Cutoff Frequency and Slope
(PDF-247K) |
|
|
Søren Bech |
564 |
|
The low-frequency loudspeaker in a 5.1 system has been investigated in
terms of perception of its frequency cutoff, slope of the cutoff, and
passband ripple. The cutoff frequency has a very significant effect on
the subjective sense of "lower bass," but the cutoff slope was found not
to be significant. The audibility of ripple depends on the nature of the
audio signal. Results were consistent in both an anechoic test procedure
and a headphone simulation of that environment. |
|
|
Comment on this paper
|
|
| |
|
ENGINEERING REPORTS |
|
Requirements for Low-Frequency Sound Reproduction, Part II: Generation of Stimuli and Listening System Equalization
(PDF-174K) |
|
|
Jan Abildgaard Pedersen and Aki Mäkivirta |
581 |
|
Using headphones to simulate the perception of loudspeakers in an
anechoic chamber is easier and more efficient, but it requires signal
processing to produce the equivalent sound signals. This study describes
the algorithms used in a previous study of the low-frequency channel
loudspeaker. Signals were pre-equalized with added nonlinear processing
based on head-related transfer measurements made in an anechoic chamber
with an actual loudspeaker. |
|
|
Comment on this report
|
|
| |
|
Reconstruction Method for Missing or Damaged Long Portions in Audio Signal
(PDF-152K) |
|
|
Ismo Kauppinen and Jyrki Kauppinen |
594 |
|
Using a reconstruction method described previously, the authors
demonstrate an algorithm that replaces gaps of up to several thousand
samples with synthesized audio. Using three different types of music,
the extrapolation method was able to reconstruct successfully the
missing audio, so that listeners could not hear the difference between
it and the original. The method was applied in practice to correct
scratches from badly damaged recordings, but it can also work with any
kind of impulse noise in real time. |
|
|
Comment on this report
|
|
| |
|
STANDARDS AND INFORMATION DOCUMENTS |
|
AES Standards Committee News
(PDF-30K) |
603 |
Acoustics and sound-source modeling
Call for Comment on REVISION of AES10-1991(r1997), AES recommended practice for digital audio
engineering-Format for the user data channel of the AES digital audio interface |
|
| |
|
FEATURES |
|
113th Convention Preview, Los Angeles
(PDF-435K) |
606 |
|
Calendar
(PDF-262K) |
608 |
|
Exhibitors
(PDF-1.1MB) |
610 |
|
Exhibit Previews
(PDF-657K) |
614 |
|
Updates and Corrections to the 2001/2002 International Sections Directory
(PDF-14K) |
636 |
|
23rd Conference, Copenhagen, Call for Papers
(PDF-20K) |
641 |
| |
|
DEPARTMENTS |
|
News of the Sections
(PDF-76K) |
629 |
|
Upcoming Meetings
(PDF-13K) |
634 |
|
Sound Track
(PDF-16K) |
635 |
|
Advertiser Internet Directory
(PDF-16K) |
635 |
|
Membership Information
(PDF-18K) |
637 |
|
In Memoriam
(PDF-28K) |
639 |
|
Sections Contacts Directory
(PDF-37K) |
642 |
|
AES Conventions and Conferences
(PDF-46K) |
648 |
| |
|
EXTRAS |
|
Cover & Sustaining Members List
(PDF-30K) |
|
|
VIP List & Editorial Staff
(PDF-26K) |
|
|
Ads In This Issue
(HTML) |
|
|
Download Entire Journal As One PDF
(PDF-4.5MB) |
|
