Ole Wolff Elektronik A/S, Roedengvej 14, 4180 Soroe
sales@owolff.com, T: +45 5783 3830
sales@owolff.com, T: +45 5783 3830
27-02-2021
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Headline:
Transducer design
Headline 2:
Ole Wolff has the experience, tools and facilities necessary to design world class drivers —from low budget to high end.
Description:
The name transducer is the fancy word for the more commonly used "loudspeaker driver" or simply "driver". As loudspeakers and especially wearable audio devices are getting smaller and smaller, it takes a lot of skills and experience to design and optimize the various elements a transducer is made of. Over many years Ole Wolff have become market-leading in this field.
Vis blokke:
Motor design
Optimizing force factor and linearity
In a dynamic transducer the motor consists of a magnet system and a moving coil. Ole Wolff designs single magnet motors as well as dual magnet motors (push-pull principle) depending on the individual performance and size target set by either the customer or Ole Wolff.
Advanced simulation tools such as COMSOL Multiphysics® are used in the development and optimization processes, taking nonlinear parameters and material properties into account. In a dynamic transducers the voice coil is moving and therefore the mechanical properties have to be taken into account as well since the mass and dimension of the voice coil will affect the the acoustic performance.
Advanced simulation tools such as COMSOL Multiphysics® are used in the development and optimization processes, taking nonlinear parameters and material properties into account. In a dynamic transducers the voice coil is moving and therefore the mechanical properties have to be taken into account as well since the mass and dimension of the voice coil will affect the the acoustic performance.
With many years of experience Ole Wolff knows the do's and don'ts in motor design but are also constantly exploring new possibilities in our efforts to develop the next generation of effective transducers.
COMSOL Multiphysics® is used to optimize the magnetic motor system.
Force factor is measured using a Klippel test system. The plot shows BL(x) for a Ole Wolff headphone driver.
Diaphragm design
Getting the design of the diaphram just right can seriously improve the speaker's linearity and frequency performance.
Designing diaphragms has during the years been based on “cut & try” engineering. This method is very time- and cost ineffective and even if huge resources are invested, there is no guarantee that the optimal design and performance has been reached. At Ole Wolff we have a faster and more reliable way of designing and optimizing diaphragms.
COMSOL Multiphysics® allow us to design diaphragms for various sizes of transducers where parameters such as foil type (single or multi layers), thicknesses of the foils, geometry of suspension, piston area and shape, number of stabilizing grooves in the diaphragm surface etc. can be simulated and performance verified before any mechanical tooling process is entered. This combined with years of experience assures shortest lead time and closest match to performance targets.
COMSOL Multiphysics® allow us to design diaphragms for various sizes of transducers where parameters such as foil type (single or multi layers), thicknesses of the foils, geometry of suspension, piston area and shape, number of stabilizing grooves in the diaphragm surface etc. can be simulated and performance verified before any mechanical tooling process is entered. This combined with years of experience assures shortest lead time and closest match to performance targets.
COMSOL Multiphysics® is used to optimize linearity of the compliance and break-up modes. Image shows motion analysis performed on a diaphragm for a 50mm receiver.
Test and verification
Good simulation results are worthless if the don't agree with real measurements.
One thing is the superior design of the transducer, another thing to document and verify the performance in the most efficient, reliable and informative way.
For testing Ole Wolff uses the most advanced testing tools and programs, such as Klippel™ analyzers & SoundCheck™ along with sophisticated custom made software.
A good graphical presentation becomes more and more important because new advanced applications such as “Active Noise Control” and other technologies are entering the market, where interaction between various performance parameters must be in focus. This could be frequency response graphs showing Maximum SPL as a function of a maximum THD limit etc.
For testing Ole Wolff uses the most advanced testing tools and programs, such as Klippel™ analyzers & SoundCheck™ along with sophisticated custom made software.
A good graphical presentation becomes more and more important because new advanced applications such as “Active Noise Control” and other technologies are entering the market, where interaction between various performance parameters must be in focus. This could be frequency response graphs showing Maximum SPL as a function of a maximum THD limit etc.
Ole Wolff uses Klippel™ analyzers to verify performance of the transducers.
A Klippel™ laser measuring a OWS-4012CW-8 speaker.
Acoustic performance is tested in the Ole Wolff anechoic chamber.