This page is updated daily as needed. Much more content is pending. Please check back for updates.
Presentations are listed in order of presentation on the schedule. These are subject to change until 30-April. Presenter biographies are included in the full abstract. Information on this page is supplied by the presenters. ALTI is not responsible for any inaccuracies or claims made herein.
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Saturday & Sunday, June 4 & 5, 2022
ALTI Keynote Speaker: 8:30AM Sunday, June 5 in the Grand Ballroom
The Golden Age of Audio is Now
By Andrew Bellavia- Knowles
People often talk of the “golden age of audio” as being sometime in the past, usually in the context of music quality. While listening to music is still a primary use case, audio has become so much more. From hearing aids to smart speakers, in-ear computers to voice-controlled cars, the audio industry has never seen such diversity of applications, nor breadth of challenges. Audio permeates our existence like never before, enriching our lives in numerous and unexpected ways.
Speaker Biography:
A life-long lover of music, Andrew Bellavia is right at home as director of market development for Knowles’ portfolio of drivers for in-ear monitors and true wireless hearables. He is also an advocate for hearing protection and care through his writing, podcast appearances, and webinars. In addition to serving on the business advisory board of ALTI, he is Knowles’ representative for IEMITO, an organization promoting in-ear monitors and their value in protecting music industry professionals’ hearing, and is a member of the advisory board of Tuned, a company delivering personalized, inclusive hearing care.
Contact info:
LinkedIn: https://www.linkedin.com/in/abellavia/
Twitter: @AndyB_Knowles
SPEAKER BUILDERS WORKSHOP
8AM to 5PM NAPA A NOTE: All start/stop times are approximate
8AM to 8:30AM: Welcome and setting “customer” requirements and how to moderate them. Barry Vogel and Stefan Irrgang
8:30AM to 9AM: Modeling and Simulation of Linear Speaker Behavior by Stefan Irrgang from Klippel
There are many unnecessarily complicated steps between receiving the customer’s specification and building a prototype that “hits the bullseye.” In this presentation, the student will learn how the innovative “Klippel Approach” reduces and even eliminates the costly iterative process of building numerous expensive and time-consuming prototypes before meeting the customer’s expectations. The Klippel Approach combines a unique and novel combination of various modelling programs readily available from numerous vendors and accurate component parts measurement. The result a is significantly shortened product development timeline. The student will learn how the Klippel Approach yields the most direct, accurate, and quickest path from concept to marketplace.
Continental Breakfast is served for Exhibitors, Presenters, and All Access Pass holders from 7:30AM to 9AM
Keynote Address by Andrew Bellavia of Knowles at 8:30AM
9:15AM to 9:45AM: Overview on Measurements of Parts– Stefan Irrgang
9:45AM to 10:15AM: Evaluation of the Prototype– Stefan Irrgang
10:15AM to 10:45AM: Loudspeaker Assembly Lecture– Justin Zazzi of Rockford Corp.
10:45AM to Noon: Students Assemble a loudspeaker– Justin Zazzi
Title: Testing Quality of Microphones
Presenter: Gregor Schmidle- NTi Audio
Time/Location: 9AM, 5 June NAPA B
Description: Due to the increasing use of microphones in many applications such as automotive or artificial intelligence, the demand for fast and reliable processes for testing the quality of the microphones is growing. In this seminar we will describe a typical microphone test system, and explain the function of each component. Besides explaining the theory, we will also perform practical measurements with different types of microphones. We will identify common pitfalls and show strategies to implement reliable and reproducible procedures.
Title: Audio Quality perception – advanced headphone measurements
Presenter: Jacob Soendergaard- HEAD acoustics
Time/Location: 11AM, 5 June NAPA B
Description: How do we properly evaluate modern headphones and headsets? Consumers can read reviews online. In some cases, they can go to a store and try them on. An additional and more objective way is to look at frequency response measurements.
- But is this parameter sufficient to evaluate the audio playback performance of an audio device?
- Is there more to the audio playback quality perception than what can be captured in a frequency response?
This paper will introduce a new quality metric, MDAQS: Multi-Dimensional Audio Quality Score, which can be used as a holistic measure of the audio quality perception in headphones (and other audio playback devices) and provide a much easier way to interpret whether the headphone is good or bad.
2PM to 2:30PM: Speaker Measurement Checklist– Aaron Lutzo of Biamp
In this session some of the basic considerations of measuring a speaker will be discussed, providing the “do’s” and “don’ts” of the technique. Have you determined the type of measurement you want? Do you have confidence in your measurement system? How do you isolate the data you want to see from the data you don’t? All and more will be answered during the session
2:30PM to 3:15PM: How to derive T/S parameters with the Parts Express DATS V3 system- Brian Myers of Parts Express/Dayton Audio
DATS V3 is a unique, multipurpose test system consisting of the hardware and full-featured software. The DATS V3 main emphasis is deriving accurate Thiele/Small parameters of a loudspeaker from the impedance profile data and is the focus of this presentation. To measure the impedance response of a loudspeaker and derive a complete set of Thiele/Small parameters is as easy as connecting a driver and starting the test! The DATS V3 system provides the electrical stimulus to the driver, measures the driver’s impedance in seconds and then creates a high-resolution graph (30,000 data points!) with no additional hardware required.
This session will demonstrate some of the DATS V3 capabilities.
3:30PM to 4PM: Introduction to Loudspeaker Testing– Les Quindipan- Loudsoft
In this short introduction to loudspeaker testing, Les Quindipan explains various loudspeaker measurements such as frequency response, distortion, sensitivity, phase/polarity and impedance, and how they might offer indications as to potential defects in a speaker. Typical test configurations for both R&D and end-of-line production test will be shown. A complete speaker test will be demonstrated using SoundCheck, and the results discussed.
Title: Enhanced Perceptual Rub & Buzz Measurement for Production Line Use
Presenter: Steve Temme
Time/Location: 2PM June 5 NAPA B
Description: Perceptual distortion measurements are often considered the holy grail of end-of-line tests because rejecting devices with only audible faults increases yield. Although such measurements have been around since 2011, production line adoption has been slow because until now, sensitivity to background noise has made limit-setting challenging. In this paper, we introduce a new algorithm that uses proprietary technology to reduce the impact of background noise on the measurement and offer more repeatable results. This facilitates limit setting on the production line, and makes it a truly viable production line metric for increasing yield. Results from various algorithms will be shown, and their correlation to subjective and other non-perceptual distortion metrics explained.
Title: FINE Suspension FEA Software
Presenter: Peter Larsen
Time/Location: 3PM June 5 NAPA B
Description: FINESuspension is Non-Linear FEA (Finite Element Analysis) software which is ideal for designing the spider and surround for most loudspeaker drivers.
Starting from a template, the user only needs to input dimensions and select a material from a database to get started.
The deformed surround is displayed in steps up and down.
The calculated stiffness versus displacement K(x) curve is now shown in the upper right window (shown on next page). When the surround is stretched out the stiffness increases, which is displayed as higher K(X) at maximum excursion up (+) and down (-). This curve shape is preferable as the increased stiffness help controlling the loudspeaker cone at extreme excursions up and down.
Ideally the U-shaped Kms curve should be symmetrical along the Y-axis. A non-symmetrical Kms curve will produce a DC offset (X) of the VC position, which would cause intermodulation distortion.
Therefore, the mirrored Kms curve is shown as the dashed curve, making it easy to spot any non-symmetries.
Title: Making Speaker and Microphone Measurements Without an Anechoic Chamber
Presenter: Tont Spica Audio Precision
Time/Location: 4PM, 5 June, NAPA B
Description: Speaker and microphone measurements are traditionally made in a fully anechoic chamber. However, it is possible to perform useful measurements of these devices without a perfect acoustic environment. In this presentation we will review techniques on how to perform meaningful measurements of speakers and microphones in a normal room.
4PM to 4:45PM: Testing Attendee Drivers
4:45PM ro 5:30PM: Wrap up and Q&A.
Take your project drivers home!
Title: Res-Core by Resonado Labs – High-Performance Racetrack Driver Architecture
Presenter: Benny Danovi and Paul Vedier Resonado Labs
Time/Location: 5:00PM June 5 NAPA B
Description: Racetrack speaker drivers, also known as oval or elliptical drivers, are becoming more prevalent every day as audio product design continues to evolve. Resonado Labs engineered a proprietary motor optimized for the racetrack driver form factor with a planar voice coil and bobbin assembly situated between parallel magnets. The technology, known as Flat Core Speaker (FCS) technology, will debut this fall under the brand name Res-Core. The bobbin runs along the length of a flat diaphragm, leading to even force distribution, and therefore pistonic movement, while utilizing a thin profile with a flat diaphragm. COMSOL simulations and Klippel measurement data support these claims and show evidence of this technology having comparable performance to conventional drivers in a slimmer profile and heavily outperforming conventional racetrack drivers.
This talk will take a deep-dive into the company’s flagship technology, Res-Core, and unveil recent structural innovations.
Monday & Tuesday, June 6 & 7, 2022
Title: Beyond Analog Circuit Modeling of Electroacoustic Transducers: Including nonlinearities and thermoviscous losses
Presenter: Stephen Thompson, PhD Penn State University
Time/Location: 8AM June 6 NAPA A
Description: Linear analysis based on analog circuit models of loudspeaker systems can be done either with analytical matrix computation methods or with a code based on SPICE or another electrical circuit analysis code. There are several good codes based on these methods that provide reasonably accurate models of small signal performance of speakers in sealed and ported enclosures. However, we must move beyond these linear models to predict large signal behavior and frequency dependent losses in enclosures and ports. Such models can be implemented with multidomain modeling codes that use the Modelica language, or with Simscape. These methods use a combination of ordinary differential equations and algebraic equations to calculate the performance in each physical domain (e.g. mechanical, electrical, magnetic, etc.) and provide the necessary physical coupling between the domains. They provide reasonable fidelity with less computational intensity than full FEA, so they can be used as components in a larger modeling system that includes programmable controls to reduce distortion or energy losses. This seminar will demonstrate the use of Simscape to model a moving coil speaker including multiple nonlinearities. It will demonstrate the ability to model a control system around the speaker for improved far field performance.
Title: Making ALTI Membership Pay!
Presenter: Barry Vogel ALTI
Time/Location: 8:30AM June 6 NAPA B
Description: People join associations for a variety of reasons. Statistics say that the vast majority of Members never use association benefits. ALTI has been very careful to only institute benefits that the majority of Corporate and Consultant Members can (and should!) really use. Find out just how good of an investment your annual association dues really is.
Title: The possibilities of engineered speaker diaphragms: Introduction to the second generation Thin-ply Carbon Diaphragms – Composite Sound Metamodal®
Presenter: Martin Turesson- Composite Sound
Time/Location: 9AM, 6 June, NAPA A
Description: The first generation TPCDs showed that it is possible to increase the range of pistonic motion while at the same time reduce the mass and achieve a more controlled behavior compared to conventional hard diaphragms. Through proper engineering, the second generation TPCD enables performance and tailored behavior far beyond what is possible when relying on material properties alone. By tailoring the thickness and stiffness (including in different directions) in any given point of the Composite Sound Metamodal diaphragm, the range of pistonic motion can be maximized, the moving mass minimized and the way resonances occur can be controlled.
Title: Listen, Inc Overview
Presenter: Les Quindipan- Listen
Time/Location: 9AM, 6 Jume, NAPA B
Description: Learn more about the products and services that Listen, Inc offers.
Click here for full abstract
Title: Controlled Loudspeaker Inductance Le(x)
Presenter: Peter Larsen- Loudsoft
Time/Location: 10AM June 6 NAPA A
Description: The Voice Coil Inductance is among the non-linear loudspeaker parameters which strongly depends on the Voice Coil position due to the influence of iron in the magnet system.
Inserting a short circuit ring around the pole piece is a known remedy for reducing the Voice Coil inductance. This will be investigated in detail using transformer theory. The inductance versus displacement Le(x) will be simulated with magnetic FEA software
In addition to a ring or pole cap, more rings and caps in different materials may be added below and above the magnet airgap depending on the coupling with the flux produced by the Voice Coil. In this way the inductance non-linearity Le(x) can be optimized to be virtually independent of the Voice Coil position.
Examples hereof are given for both normal outside ferrite magnet systems as well as inside neodymium magnet systems.
Title: What is the best high frequency response for earphones? (Extending the Harman Curve)
Presenter: Cristina Downey and Tom Miller- Knowles
Time/Location: 10AM June 6 NAPA B
Description: Sean Olive and team did a fantastic job developing the Harman recommended curve for earphone response. This curve has been widely adopted by the earphone industry. However, they admittedly didn’t really study response above 10 kHz, citing technical limitations of the gear at the time. Knowles has taken up the challenge of discovering what listeners really prefer for that last octave of music, using methods similar to Sean’s along with improved equipment. The results are surprisingly brighter than the Harman curve. We will describe how we developed a new recommended headphone curve, and how we overcame the challenges of getting reliable listener results at high frequencies.
Title: Application of Musical Modulated Multitone stimulus for detection of non-harmonic distortion in horn drivers
Presenters: Alex Voishvillo, Balazs Kakonyi- JBL/Harman Professional
Time/Location: 11AM June 6 NAPA A
Multitone stimulus is known to provide test results that have a better correlation with perceived sound quality than a swept sine wave stimulus. An exhaustive review of multitone theory, history, and application is presented in [1] and [2] by Czerwinski et al. A well-known publication on multitone by R. Belcher [3] presents experimental evidence that multitone stimuli provides superior correlation with the audibility of nonlinear distortion than swept sine wave stimuli. Multitone stimuli, used in [1]-[3], have an equal spacing between the tones on a logarithmic frequency scale. Subjectively, the stimulus sounds anharmonic, dissonant, and noise-like.
The new MMM (Modulated Musical Multitone) signal was developed to bridge the gap between objective testing data and subjective perception of sound. The MMM signal consists of E-minor triads in several octaves with amplitude modulation to match the crest factor of particular musical signals.
In [4], MMM was used for the detection of audible distortion in horn drivers. In [5], the nonlinear response to the MMM signal was post-processed in the frequency domain to obtain the Multitone Total Nonlinear Distortion (MTND) response. MTND represents all the nonlinear distortion products averaged within a sliding window in the frequency domain [6]. The windowed and averaged value of spectral components within the sliding window are then plotted at the center frequency of that window. By repeating this process at different frequencies, distortion products can be identified across the frequency domain. In [5], this approach was used to profile nonlinearities in full-band loudspeaker systems by calculating MTND responses across various input voltage levels and plotting them as 3D graphs.
Title: Multi-Domain Transducer Measurement
Presenter: Kent Peterson Warkwy Associates
Time/Location: 11AM June 6 NAPAB
Description: Electro-acoustic transducers used in loudspeaker systems typically translate an electrical signal into acoustic sound by mechanically actuating a diaphragm or cone with an electro-magnetic motor. Comprehensive transducer testing therefore requires a multi-domain approach with measurements in all relevant domains: electric, mechanic, acoustic, and magnetic.
A broad range of measurements and methods will be shown including single point measurements, distributed measurements (laser scanning) and measurement methods based on model fitting for linear as well as non-linear behavior. The multi-domain measurement approach provides a wealth of relevant data, enables a much deeper understanding of the transducer, its behavior and its defects, and enables symptoms to be linked to their actual root causes. The presented measurement methods are in most cases faster than traditional measurements and only require normal semi-reverberant rooms with minimal acoustic treatment. This enables savings in time and resources both in the short and long run by reducing measurement time, eliminating the need for special facilities like anechoic rooms and, cutting down research time and the amount of necessary prototype iterations.
This presentation discusses important electrical, mechanical, and acoustical measurement performed on the KLIPPEL Multi-Scanning Workbench according to IEC 60268-21 and 22. Kent Peterson will be joined by Dr. Stefan Irrgang of Klippel GmbH.
Title: Global Supply Chains In Chaos – Strategies For Moving Forward
Presenter: Rosemary Coates
Time/Location: 2PM June 6 NAPA A
Description: We’ve all experienced the chaos of supply chains during the pandemic. Shortages of products and parts caused by factories closing and opening and closing again and skyrocketing logistics costs have wreaked havoc. Shifts in demand and the persistent import tariffs make global sourcing unpredictable and more expensive. These things and others have been a true wake-up call for manufacturers.
What strategies for mitigating risks in the future should be considered? Where in the world should you look for sources now? Should you try to develop domestic suppliers? Should you maintain higher inventory levels? Is inventory sharing across the industry possible? What kind of disaster planning should you undertake for the future? What opportunities are on the road ahead?
Rosemary Coates will introduce new ideas for you to consider and what manufacturers are doing now that will change the landscape of manufacturing in the future.
Title: AC Power, Grounding, and Shielding
Presenter: Bill Whitlock
Time/Location: 2PM June 6 NAPA B
Description: Bill Whitlock of Whitlock Consulting shares results of his own peer-reviewed research and 30 years of experience at solving system noise issues for thousands of Jensen customers. He’ll debunk common myths and pseudoscience by explaining, in simple “electronics 101” language, the physics underlying hum and buzz in audio systems and “random” misbehavior in digital systems. You’ll learn relevant aspects of National Electrical Code and what normal AC power is and how it indirectly causes noise problems. You’ll discover why light dimmers are so notorious for causing “buzz” in sound systems and what simple steps can be taken in new systems to avoid the problems altogether. For existing systems, a simple no-instruments troubleshooting method teaches how to use observation, system controls, and simple logic to pinpoint the exact cause and location of a noise issue. A variety of solution strategies and devices will be compared with respect to performance, cost, and safety, including why some so-called “solutions” actually put your customer’s life at risk – and expose you to lawsuits. Attending this course will not only make you smarter but you’ll avoid the embarrassment and expense of recalls to fix the system … your hard-earned reputation is at stake!
Title: Supply Chain Challenges
Presenter: Panel Discussion
Time/Location: 3PM June 6 NAPA A
Description: An open discussion of the current challenges, what we can expect going forward, and solutions to ease the pain.
Title: TBA
Presenter: Steve Temme Listen, Inc
Time/Location: 5PM June 6 NAPA A
Description: TBA
Click here for full abstract
Title: How Do I Get Good Data?
Presenter: Aaron Lutzo- Biamp
Time/Location: 4PM, 6 June, NAPA B
Description: When testing a loudspeaker, so many moving variables can open the door for inaccuracies in your measurements. The test engineer or acoustician breaking into the field will undoubtedly have questions as they dive in. This session in focused on providing tips towards “getting good data”, and saving yourself time on the essentials. We will discuss understanding the type of measurement you are after, isolating what you want to see from the test environment, and keeping in mind the resolution and bandwidth of your data. All this will then be related to balloon modeling data used frequently in the pro audio industry.