audioXpress Magazine      March 2023

  audioXpress remains the authority on audio and reproduced sound by connecting manufacturers and distributors with developers, buyers and consultants around the globe! It's readers are the audio product designers, consultants, integrators, DIY enthusiasts, opinion leaders and your best customers. All of them agree that the coverage of trending topics, unique in the audio industry, make audioXpress a must read.

Every month, audioXpress combines the best educational articles on topic such audio electronics, speaker and headphone design, amplifiers (from tube to Class D), acoustics, practical test and measurement, audio engineering praxis, and standards. audioXpress provides inside stories on new audio developments, on R&D Stories, the most complete objective reviews of innovative products and software, and selects some of the best DIY audio projects from worldwide experts.

4 From the Editor's Desk: Invitation-Only Audio History
This is also a problem for the organizers of CES.
Editorial By J. Martins
Since returning from CES 2023, I feel there are some experiences and impressions that are worth leaving here for posterity. After nearly three years with no major trade shows contributing much in terms of surprises and excitement, the annual Las Vegas, NV, event was clearly a great way to kick start the new year. It wasn't a big event for new products launches, nor did it signal the introduction of new technologies of which we weren't aware. Plenty of new products were already launched in 2022, simply because many companies were forced to postpone their planed introductions for nearly two years due to the global pandemic. And most of the technologies we got to see at CES 2023 were in fact things we have been reporting for some time. So, why the excitement?
---> Invitation-Only Audio History.

5 Supporting Companies

66 Xpress Mail

Features
40 Burkhard Vogel's Slopes And Levels
SPICE Models To Simulate Vintage Op-Amp Noise
Review by Marcel van de Gevel
Interested in accurately simulating the noise of
op-amp circuits? Burkhard Vogel wrote a book that
addresses this relevant topic for any audio circuit
designer who doesn't want to rely just on the
manufacturer's own models.

44 Lumped Element Modeling Of Transducers
By René Christensen
Many engineering tasks require a common ground
from which discussions among those involved in a
project can take place in a structured manner. This
will often involve a so-called model of the concept or
product, and this article discusses one such model:
the lumped element model.

50 Modern PC Board Design Practices
Part 2: Tips And Techniques
By Ethan Winer
In Part 1 of this article Ethan Winer gave a general
overview of modern PC board design using surfacemounted
devices (SMDs). Part 2 continues with
specific techniques and advice.

56 Power Transformer Parameters, Selection, And Testing
Part 5: Losses
By Chuck Hansen
The initial group of articles focused on the history
of transformer cores, construction methods and
materials, and various testing methods. After having
discussed the parameters of transformers, this article
expands on their losses.

Hollow-State Electronics
62 Accuracy In LTspice Modeling
By Richard Honeycutt
Sometimes we need to consider the human factor when
using circuit design simulation tools. In this article, our
hollow-state expert details an error that occurred in a
past article, which is now being corrected.

Test & Measurement
8 Echo AIO
A Cost-Effective Audio Test System
By Stuart Yaniger
Headquartered in Santa Barbara, CA, Echo Test + Measurement
is a little company with a big impact on audio test
and measurement for consumer electronics. Based on its sound
card technology, it created a full modular test interface range,
which Stuart Yaniger had
the opportunity to evaluate.

Market Update
18 Modular Evolution In Audio Testing
By J. Martins
The audio industry continues to benefit from significant
progress in advanced software as well as modular
hardware solutions. This market update offers an
overview of the latest audio and industry-related test
and measurement solutions, identifying market trends for
this critical segment.

28 Acoustical Measurement And DSP Amplification in
Automotive Audio
By Philipp Paul Klose
This article offers a primer on how to approach acoustic
measurements and the practical application of DSP in
car cabins, one of the hardest acoustic environments for
quality sound reproduction. The topics addressed in this
article will be expanded in future articles.

34 Transitioning Audio Tests From R&D To The Production Line
By Steve Temme
Production line audio testing poses many challenges
such as noisy environments, harsh operating conditions,
high throughput, relative limits, and more. In this article,
Steve Temme shares his observations and outlines the main
considerations to ensure a successful operation.

Subscribe To audioXpress Magazine
Click here to subscribe to audioXpress magazine.

Previous Issues

2023
January   February

2022
January   February   March   April   May   June   July

August   September  October  November  December  

2021
January   February   March   April   May   June   July

August   September   October   November   December

2020
July   August   September   October   November   December