Virtual ALTI-EXPO 2020

As a service to our Members and to the Exhibitors who have been adversely affected by the global Pandemic, ALTI was pleased to offer a one day, online Virtual event on June 15, 2020  This event was FREE to attend. Membership not required. We understand that our scheduled presentations may not be convenient for all attendees depending upon your time zone. All presentations were recorded and are available now. See the URL  with the abstracts below to view the webinars.

Scroll down this page to see the presentation abstracts and the URL’s to view them. If there is no URL listed for the webinar you hoped to see, that means this webinar was cancelled due to technical issues. Look for them at Virtual ALTI-EXPO 2!

Virtual ALTI-EXPO 2 coming July 15, 2020. Look for details and registration soon!

Multidimensional Optimization of professional Audio Systems Using Advanced Multiphysical Models  9AM

By Thomas Gmeiner- Mvoid

The fundamental principle of virtual product development is to optimize the performance of products and systems in the early phase of the development process. Engineering is the art of realising desired functions by technical solutions embedded in a system of interacting elements. Multi-dimensional target requirements come with trade-offs to be made and the quest for the best product boils down to finding the sweet spot between all the interacting influences. The optimal product is the treasure of companies, nurtured by the business processes linking market research, customer relations, product management and engineering, traditionally grown by experience and empirical know-how.
Virtual product development adds and changes the process landscape by new approaches: Product designs can be varied over a wider range to explore what is theoretically achievable. The planned product can be consciously positioned within the explored space, therefore better understood and explained to the customer. User tests can be performed with the virtual prototypes to confirm decisions or explore new properties.
Audio systems act in various physical regimes. For a full digital model, a combination of simulation methods, mesh sizes, mathematical models and physical theories must be applied. The application of the methodology is presented with a use-case of optimizing a subwoofer.

The Roadmap Towards Digital Twins For Automotive Audio Systems  9:30AM

By Dr. Alfred J. Svobodnik- Mvoid

Digital twins are one of the most important technology trends, currently reaching a maturity level that allows entering mainstream use. In product development, production and service, the use of this technology promises vast benefits through the possibility of monitoring the behavior of products and production processes with the help of a digital twin, developing new customer oriented services or drawing conclusions for product improvements from product data. Digital twins can change and accelerate the entire engineering process.

Audio systems in production vehicles are known to exhibit vehicle to vehicle performance variance. Hence, such systems are an ideal candidate to utilize the digital twin method where e.g. particular attributes can be modified between comparisons. Adopting loudspeaker drive units from within manufacturing tolerance, system comparisons and thus performance changes can be assessed and improved.

The digital product twin of sound systems in vehicles additionally helps to explore the impact of different design alternatives and allows simulations and tests to ensure that product designs meet the requirements and fulfill customer expectations.

Testing Quality of Microphones  10AM

By Gregor Schmidle- NTi Audio

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.

Linking Cost, Performance, End-User Satisfaction by Physical and Perceptual Assessment  10:30AM

By Wolfgang Klippel- Klippel GmbH

This tutorial discusses the maximization of the end-user value, which determines the success in the market. The end-user value can be described more practically by the performance/cost ratio which considers physical, perceptual and other non-technical features and the cost structure of the product.
The discussion starts with the target performance as seen by the end-user, which is the basis for the development. The tutorial focuses on the assessment of the sound quality and discusses listening tests, auralization techniques and perceptual modeling to define the audibility threshold and the impact on the end-user value to generate acceptable tolerances. Those are required to generate meaningful specifications and PASS/FAIL limits. The manufacturing process should provide the defined performance at minimum production cost and with practical risk management (prevent field rejects). The discussion ends with new opportunities provided by digital signal processing and electrical control for in-situ monitoring and improving the performance, endurance and reliability of the product in the final application.

Towards Digital-Electro-Mechano-Acoustical Transducer Modules  11AM

By Wolfgang Klippel- Klippel GmbH

This tutorial discusses the new opportunities for creating all-in-one active transducer modules that combine adaptive, nonlinear control and other DSP algorithms, amplification and electro-acoustical conversion. Those modules only have a digital input for audio streaming and communication and use a simple, cost-effective power supply. They can be used in any enclosure with additional acoustical components (e.g. passive radiator) to realize headphones, conventional loudspeakers and modern arrays for 3D audio applications. The main objectives are to maximize the overall efficiency and minimize the cost by matching the components to each other. Current sensing at the terminals is the basis for the adaptive nonlinear control which generates a desired linear transfer behavior of the system over product life. The tutorial addresses the consequences for the practical system design and the benefits for the end-user.

Multidomain Modeling of Speaker  Nonlinearities with Simulink and Simscape 11:30AM

Rescheduled to our July 15 event!

By Stephen Thompson, PhD- Penn State University

Multidomain modeling of acoustic transducers can be implemented in many ways, from older analog circuit tools such as SPICE to modern multidomain FEA tools. Each level of model complexity has its place. An intermediate level of complexity is available with tools such as those that use Modelica or Simscape. These are not full partial differential solvers. They 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, 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.

Modeling a Planar Carbon Nanotube (CNT) Speaker  Noon 

By Siraj Prabhu- Michigan Tech University 

CNT speaker technology was first demonstrated at ALTI by Mahsa Asgarisabet, Troy Bouman, and Dr. Andrew Barnard in 2016. Currently, research is ongoing for using CNT speakers for active noise cancellation devices in pipes and ducts. Focus areas of application are noise cancellation in automotive exhaust, and automotive and industrial HVAC systems. Different designs of the CNT speakers are being tested for their suitability to specific applications as well as to obtain better performance. Advantages of CNT speakers include order of magnitude reduction in speaker size and weight, ability to operate in high temperature environments, and when designed in a coaxial manner, do not invoke any back pressure on pipe and duct systems.

The main focus of this research is to develop a method to model an enclosed, coaxial CNT speaker for automotive exhaust applications. The modeling method will be developed using COMSOL Multiphysics. However, the complex physics of the problem required validation of modeling techniques. A modeling method will be validated using the testing results and will include the effect of flow and temperature of the ambient medium on the speaker performance. This paper shows a comparison between a finite element model in MATLAB, multiphysics model in COMSOL and the analytical equations for the SPL generated by an open planar CNT speaker. This comparison will assist in validating the coupling method used in the COMSOL model as well as understanding the process used by COMSOL for simulating the planar CNT speaker. Validating the simple planar CNT speaker model is crucial as similar coupling between the physics will be used for a more complicated model of an enclosed, coaxial CNT speaker in COMSOL.

MEMS based Audio Speaker Module   12:30PM

By USound GmbH

This paper introduces a novel MEMS technology based audio module for in-ear headphone applications. The device has a small form factor with the whole audio module integrated inside the tip of an in-ear headphone. It is a complete audio solution containing a surface mounted MEMS speaker, an integrated audio amplifier with energy recovery, a digital MEMS microphone as well as digital signal processing for equalization and open-loop predistortion. The module can be manufactured in an SMT line enabling fully automated high-volume mass production with low costs and high yield. 

The mechanical structure and key benefits of a MEMS based speaker module are discussed in detail, along with the fundamentals of the audio amplifier implementation and signal processing. 

Change Is Here To Stay – China’s Perfect Storm and Where Do We Go from Here  1PM

Rescheduled to our July 15 event

By Mike Klasco, Menlo Scientific

Over the last few decades we have all grown complacent with sourcing our products, or at least most of our components, from China. Long established relationships, trustworthy suppliers that know what we want and need, are losing their position as viable vendors. The rising cost of goods from China, the tariff war, the Hong Kong struggle with Beijing, and now the corona Virus have reached the tipping point and staggered what was once the obvious country of choice for audio products. The tariff war was sold as re-shoring – bringing our production back home – yet it seems that we have just further burdened ourselves with adding the tariff to ourselves and sent most of us looking elsewhere in Asia for new suppliers.

Vietnam, Philippines, Indonesia, Malaysia, Thailand, India, not to mention Korea, Myanmar and Cambodia – are all getting finding themselves bathed in the first waves of brands exploring their options. We will review the landscape of long established as well as new speaker factories.

 What about bringing the audio business back home? We have the stick of tariffs that we have beat ourselves with, how about the carrot of tax incentives, grants and matching funds for R&D –perhaps these perks contingent on the new technology built in the U.S. ideally in state-of-the art factories similarly incentivized.

Finally, a discussion of how should ALTI help its members navigate through the storm?

Engineering Student’s Guide to Loudspeaker Design  1:30PM

By Mark Glazer- ALTI Board of Directors and Harman International

There is an increasing demand for loudspeaker engineers due to the growing market of “smart” loudspeakers. This presentation will enlighten the student with knowledge on loudspeaker engineering, as well as how to design your own bookshelf speaker. Topics discussed will be, loudspeaker directivity and the Listening room, loudspeaker linearity, design goals, transducer design and selection, Thiele-Small definition and measurements, transducer measurements, enclosure design and construction, crossover design, and system measurements


Advanced ANC Headphone Measurements

By: Jacob Soendergaard, Telecom Account Manager, HEAD acoustics, Inc. 

ANC headphones have come a long way and are getting increasingly more sophisticated. One popular ANC feature is what’s sometimes called Talk-Through mode, where a user can easily interact with the outside world without having to remove the headphones, or strain to understand audio clues and speech.

But how do we quantify the performance of the Talk-Through mode? And how do we determine if the implementation makes a positive difference to the headphone users?

This presentation will highlight the Listening Effort metric – standardized in ETSI TS 103 558 – and apply it to a variety of commercially available headphones and ultimately evaluate how successful those products are in improving the listening and conversational experience in noisy environments.

Author Contact info:

Jacob Soendergaard, Telecom Account Manager

HEAD acoustics, Inc.

O: 248 486 0099 xt 228

C: 248 321 9075

F: 248 486 9470


6964 Kensington Road

Brighton, MI 48116

Warkwyn Associates Facility Tour  2:30PM

Rescheduled to our July 15 event.

By Kent Peterson- Warkwyn Associates

In the Spring of 2019 Warkwyn’s parent company; MISCO built a completely new speaker factory and moved a short distance from Minneapolis, over the Mississippi River, and to Saint Paul Minnesota. This afforded Warkwyn to build completely new lab, demo, listening and sales spaces to conduct business. Please join Warkwyn for a quick spin around the new spaces in a virtual tour where we can show where and how we do business, our capabilities, and where and how we use both Microflown and Klippel instrumentation.

COMSOL Multiphysics Workshop  3PM to 4:30PM

Rescheduled to our July 15 event

By Jinlan Huang, PhD

This workshop will be divided into two sessions. In the first session, we will give an overview on the capabilities of COMSOL Multiphysics in loudspeaker simulation to different level of complexities. A specific model example will be presented to showcase how COMSOL may be used not only to simulate the behavior of a loudspeaker but also to optimize its design to the desired specifications. 

In the second session, the attendees will have a chance to use the trial software to create a simplified loudspeaker model right in the classroom by following the leader. You are able to learn the basic work flow in creating a multiphysics model inside COMSOL that includes defining global parameters, importing CAD models, setting up acoustic-structure interaction physics, meshing, solving, and postprocessing.

Prior sign up to the 2nd half hands-on session it is required to get a trial license so that the COMSOL Multiphysics software can be downloaded beforehand. (NOTE: Details of preregistration will be posted in March, 2020. Bring your laptop or media device to participate in the hands-on segment. There is no fee to attend this workshop)

Resonado Introduces Flat Core Speaker Technology  4:30PM

 By Darrell Adams – Resonado, Inc.

Technology across industries has always followed the trend of getting thinner, lighter, more efficient, and more sustainable. The speaker industry has had numerous breakthroughs that have catered to that trend with flat driver technologies; yet if you take apart virtually any mass-produced audio-emitting device today, you’ll still find a conventional cone-type electrodynamic loudspeaker as the source of sound.Why? None of these flat driver technologies have been able to hit a level of ubiquity because they all lack in at least one crucial aspect: cost, scalability, sound quality, or ease of full frequency spectrum reproduction. Resonado’s proprietary Flat Core Speaker (FCS) technology, a new take on the electrodynamic loudspeaker structure that implements bar magnets with a planar voice coil mounted perpendicularly to its flat “racetrack” diaphragm, is primed to be the first.

All attendees are invited to learn how Resonado, a startup from the University of Notre Dame, became a rapidly growing company with transducer technology that has garnered attention from multinational industry leading corporations, Silicon Valley venture capitalists, and mainstream media. The majority of the session, however, will be devoted to providing insights into the significant benefits FCS technology can provide, due to its aspect ratio and innovative motor structure, in varying applications across industries.

What Is New In Materials for the Speaker Industry  5PM to 6:00PM

Rescheduled to our July 15 event

By Mike Klasco- Menlo Scientific

A wide range of new formulations of materials – with enhanced acoustical characteristics have recently entered the market. 
Applications range from woofer cones to tweeter domes and compression drivers diaphragms to enclosures for soundbars to headphone earcups.
While some of these materials were first introduced last year, we can now discuss their application in products which are shipping.