Ole Wolff Elektronik A/S, Roedengvej 14, 4180 Soroe
sales@owolff.com, T: +45 5783 3830
02-06-2020

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Headphones and earphones

Headphone design from the ground up based on years of experience.

Ole Wolff has years of experience in Headphone & Earphone designing helping customers to achieve exactly the sound impression “finger print” they want.

There are several sound tuning parameters in the transducer design as well as the way the transducer is built into the Head- & Earphone, and we are proud to be one of our customers most preferred partners in the field of doing this.

headphones1

Design target

Getting the sound you want.

Such thing as  the “one and only” frequency response shape giving the most natural sound impression does not exists.

We see a lot of variety in our customers preferred response target, and there is a significant difference in the preference from Eastern to Western part of the World.
Some of this can be explained by physiological differences in the ear canal size/dimension between Asian and Western human being populations and others are probably caused by differences in the music style and music traditions in between the regions mentioned.
However, Ole Wolff will adapt to these different requirements and contribute heavily to the reach of the individual target performance our customers have set up.

HP_design_target
A measured headphone response (magenta curve) compared to the target response (blue curve).


Simulations

Analyzing and understanding the acoustics is key

At Ole Wolff we offer to set up an acoustic simulation network of our customers actual application containing all the elements in the transducer as well as in the Head-& Earphone design, which will influence on the sound performance.
These are expressed as the TS parameters.
By this setup, we can quite accurate predict the sound performance and match this to our customers wishes.
Usually we share these networks with customers as well, so we can run parallel simulations at both parties for best cooperation.

When getting closer to the actual mechanical design target of the Head or Earphone project involved, we perform a 3D simulation based on Comsol, which comes even closer to the real live audio performance to be expected.
This step gives our customers even more confidence in the design phase leading to a short and cost effective development cycle.

Sim_tools

Very often both 2D and 3D simulations are used to simulate the influence of leakage holes, front- and rear cavities etc.


Prototyping

Drilling holes, modifying front-to-back leakage, changing mesh densities...

The above mentioned simulation tools helps us in giving the customer a very short delivery time for actual having the prototypes in hand for initial listening tests and also laboratory tests for documentation.
Normally “soft Tooling” parts will be made based on these simulation results using 3D printing. Laser Cutting, CNC processing, etc. leading to hand assembled prototypes ready for sharing with our customers for their evaluation.

Prototyping
Example of tuning the acoustics of an earphone by blocking leakage holes and reducing front volume using sticky tack.


Verifying the performance

Using standardized test methods

The Laboratories at the Development sites of Ole Wolff in Denmark and China are fitted with the most advanced standardized measurement equipment especially developed for the verification of performance of professional audio consumer products.
This includes Artificial ears, Head& Torso simulators, Anechoic Chambers etc. and are all parts of standardized test methods used and acknowledged all over the World.
This makes us possible to communicate test results in same technical “language” as our customers as well as other independent laboratories are using.  

711

A 711 coupler used for testing an in-ear earphone.


Hats
The Ole Wolff head and torso simulator measuring a pair of noise cancelling headphones.



DSP tuning

Ole Wolff can do the tuning and provide the filter coefficients.

Not always can the preferred target audio performance be reached by the tuning of the acoustic parameters themselves in the Head - & Earphone.
In such case, very often a Digital Signal Processing (DSP) can support to achieve the final shaping of the Frequency Response desired for the device.
Here Ole Wolff can also contribute with the supplying of the needed filter coefficients matching our customers DSP capabilities in their specific project.