ADD.Sound® – Active Tonal Noise Reduction in the Drive Train
ADD.Sound is an active system for reducing tonalities in wind turbines. It measures vibrations directly on the gearbox, calculates in real time the counterforces required and applies them precisely in phase via actuators. This actively stabilises the drive train and significantly reduces the emission of tonal noise – with full energy yield and unchanged operating behaviour.
Operating principle – Active control for targeted tonal noise reduction
The system operates in a closed control loop consisting of sensors, controller and actuators:
- Sensors record the gearbox vibrations,
- the controller calculates in real time the counterforces required,
- actuators generate these forces precisely in phase and compensate the excitation.
With this principle, the tonal components – that is, the narrow-band frequencies perceived as tonalities – are reduced by up to 10 dB. The effectiveness depends on the degree of tonality, its frequency range and the turbine’s operating state.
Depending on the characteristics of the tonalities, ADD.Sound can also have a positive influence on the overall sound level. Experience shows that a reduction of tonal components can lead to a measurable decrease in the overall sound level within the relevant operating range.
![[Translate to English:] Querschnitt WEA Anwendung ADD.Sound](/fileadmin/_processed_/d/9/csm_2025-10-ADD-Sound-Anwendung-Querschnitt_21c4f48a7c.jpg)
Integration into new or existing wind turbines and concepts
ADD.Sound can be used both during the development phase of new turbines and in existing wind turbines. Owing to its modular design, the system can be flexibly integrated – directly on the gearbox or in the hub – and thus adapted to different drive train concepts and installation space requirements.
Fast amortisation due to increased yield
By moving the black dots you can calculate your individual payback period with our interactive tool. This calculation includes all costs including installation.
Amortisation after
12months
not possible
What makes us the technology and market leader in the field of active damping solutions
ADD.Sound combines efficiency, flexibility, and scalability to ensure optimal vibration damping in wind turbines.
- High force scalability through multiple actuators, allowing flexible adaptation to various requirements.
- High damping force with minimal moving mass, enabling efficient vibration reduction.
- Flexible positioning on the gearbox or hub thanks to a modular concept, facilitating easy integration even in confined spaces.
- Retrofit option available, allowing for seamless upgrades to existing systems.
- Broadband compensation across the entire operational range, without the need for hardware adjustments.
- Simultaneous compensation of multiple vibration orders (Single or synchronous damping of 1st and 2nd gear mesh / excitation frequency).
- Damping of all relevant gearbox or hub modes (e.g., rolling, yaw, pitch, and torsion).
The advantages at a glance
Proven, robust system
with field-tested hardware
7 customers,
including 5 OEMs
Reduction of tonality
by up to 10 dB
3.000+
actuators delivered
5,000 N damping force
per actuator
15 + turbine types
equipped – with or
without gearbox
References
When wind turbines start to swing, individual frequencies can become audible in the background noise of the turbine. Such sound content is particularly unpleasant to the human ear. Therefore, there is a risk of surcharges in the evaluation of noise emissions and reduced power operation. Active vibration dampers can
reduce these frequencies.
Please contact us personally
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We will be happy to support you with any questions regarding the efficient reduction of tonalities as well as our active vibration damper ADD.Sound.
Industrial engineering in dual study programme, Osnabrück University of Cooperative Education
Bachelor of Engineering (B.Eng.)
Let the wind do its job!
A family business of colleagues with such deep expertise that we can work at eye level with the leading international OEMs in the wind industry.
Very broad field of work with the opportunity to tackle and implement things.
Great colleagues with fun and joy.
Cool location in Hamburg :-)
Civil Engineering, TU Berlin
Dipl.-Ing.
WAB e.V.
"Paths are created by walking them." (Franz Kafka)
Working independently in a flexible, highly innovative company that makes a little contribution to the energy transition.
Sales Engineering and Product Management, Ruhr University Bochum
Master of Science (M.Sc.)
The collegial, friendly, and fair interactions, the unwavering helpfulness of all colleagues, and the genuine sense of working together towards a common goal. Additionally, the strong company know-how and immense variety naturally foster joy in the work.
Wirtschaftsingenieur an der FH Westküste in Heide
Bachelor of Science (B.Sc.)
"The secret of success is to do the common thing uncommonly well." – John D. Rockefeller Jr.
Working in an innovative company that works together to develop solutions for a sustainable future. As a young professional, I particularly appreciate the friendly and helpful colleagues. Wölfel also offers a varied working environment in which exciting projects are designed and successfully implemented together with the customer.
Applied Foreign Languages and Business Administration, Justus-Liebig-University Giessen
Diploma Business Anglicist / Romance Studies
Work hard, be yourself and have fun.
The wind energy sector is very inspiring. My motivation is to support the world and customers with our products.
Industrial engineering in dual study programme, Osnabrück University of Cooperative Education
Bachelor of Engineering (B.Eng.)
Let the wind do its job!
A family business of colleagues with such deep expertise that we can work at eye level with the leading international OEMs in the wind industry.
Very broad field of work with the opportunity to tackle and implement things.
Great colleagues with fun and joy.
Cool location in Hamburg :-)
Civil Engineering, TU Berlin
Dipl.-Ing.
WAB e.V.
"Paths are created by walking them." (Franz Kafka)
Working independently in a flexible, highly innovative company that makes a little contribution to the energy transition.
Sales Engineering and Product Management, Ruhr University Bochum
Master of Science (M.Sc.)
The collegial, friendly, and fair interactions, the unwavering helpfulness of all colleagues, and the genuine sense of working together towards a common goal. Additionally, the strong company know-how and immense variety naturally foster joy in the work.
Wirtschaftsingenieur an der FH Westküste in Heide
Bachelor of Science (B.Sc.)
"The secret of success is to do the common thing uncommonly well." – John D. Rockefeller Jr.
Working in an innovative company that works together to develop solutions for a sustainable future. As a young professional, I particularly appreciate the friendly and helpful colleagues. Wölfel also offers a varied working environment in which exciting projects are designed and successfully implemented together with the customer.
Applied Foreign Languages and Business Administration, Justus-Liebig-University Giessen
Diploma Business Anglicist / Romance Studies
Work hard, be yourself and have fun.
The wind energy sector is very inspiring. My motivation is to support the world and customers with our products.
![[Translate to English:]](/fileadmin/_processed_/9/a/csm_Windenergie_01_Schall-laerm_1000_875_24d90de6fe.jpg "[Translate to English:]")
