Effectively absorb low-frequency sound – How to create a pleasant sound environment
Low-frequency sound, that is, tones below 200 Hz, is a common problem in homes, offices, restaurants, and public spaces. These sounds are characterized by longer wavelengths that easily pass through regular thin absorbers. Typical sources of disturbance include traffic noise from heavy vehicles, rumbling ventilation systems, heat pumps, bass sounds from music and nightclubs, as well as structure-borne noise from machines and household appliances. The low frequencies are often perceived not only through the ears but also as vibrations in the body, which can cause stress, irritation, and discomfort.
To effectively reduce low-frequency sounds, specially adapted acoustic solutions are therefore required. Here we explain how to create a calmer and more pleasant sound environment.
Why is low-frequency sound so difficult to absorb?
Low tones have significantly longer wavelengths than high-frequency sounds, which means they more easily pass through thin materials. This makes standard absorbers, often used for high-frequency sound, insufficient. Instead, specially designed thick and high-density materials are needed to effectively absorb low-frequency sound waves.
Best methods for absorbing low-frequency sound
To achieve effective absorption of low-frequency sound, you should use broadband absorbers, also known as bass absorbers or bass traps. These absorbers are thicker than traditional sound absorbers, often between 100–200mm, and are specifically developed to capture and convert low-frequency sound energy into heat. By installing these with an air gap behind, their effect is further enhanced, which is particularly effective in the frequency range around 50–500 Hz.
Place bass traps in room corners for optimal effect
The corners of a room are areas where low-frequency sounds gather and amplify due to wave reflections. Therefore, corner-mounted bass traps are one of the most effective measures for reducing low-frequency sound problems. These bass traps should have a thickness of about 300–600mm depending on the room size and sound levels. By strategically placing bass traps in the corners, you can significantly reduce low-frequency resonances and create a balanced sound environment.
Membrane absorbers for specific frequencies
In some situations, when particular frequencies are especially problematic, membrane absorbers – also known as panel absorbers – are an effective solution. These absorbers consist of a dense front panel and an air cavity behind, allowing them to be tuned to absorb a specific low-frequency tone, usually between 50–150 Hz. Membrane absorbers can be custom-designed and placed precisely where they are most effective, making them ideal for music studios, cinemas, and rooms where audio precision is crucial.
Helmholtz resonators – Special solutions for low-frequency sound problems
Helmholtz resonators are another effective special solution for managing low-frequency sound. These resonance boxes are carefully dimensioned to absorb specific frequencies. Although they require advanced design, they are highly effective and compact solutions, perfect for rooms where space is limited but where low-frequency noise is a significant issue.
Combine methods for the best results
For the best possible sound comfort, a combination of the above solutions is recommended. Start with corner-placed bass traps and then complement them with broadband absorbers on walls and ceilings. If needed, you can add custom-tuned membrane absorbers or Helmholtz resonators for specific frequency ranges.
Create a pleasant sound environment with effective low-frequency absorption
By using the right materials and strategically placed bass traps, membrane absorbers, or Helmholtz resonators, you can effectively reduce low-frequency noise and vibrations. Whether the problem occurs at home, in the office, restaurant, or public space, a good sound environment improves both comfort and health for those present. Absorbing low frequencies is a long-term and wise investment for anyone looking to create a stress-free, calm, and harmonious environment.