Lågfrekvensfälla

Lågfrekvensfälla is a Swedish term that translates to "low-frequency trap." It refers to a type of acoustic treatment designed to absorb or mitigate low-frequency sound waves, typically in the range of 20 Hz to 200 Hz. These are the frequencies that often create problems in enclosed spaces, such as room modes, resonances, and muddiness.

Low-frequency traps are usually constructed to be substantial and are placed strategically within a room, often in corners or along walls where low-frequency energy tends to build up. Common designs include Helmholtz resonators, which use a specific volume of air coupled with a port or opening to resonate at a particular frequency and dissipate the sound energy as heat. Another common type is the panel or membrane absorber, which consists of a flexible panel that vibrates when struck by sound waves, converting the acoustic energy into mechanical energy and then into heat. Porous absorbers, while effective for higher frequencies, are generally too thin to significantly impact the longer wavelengths of low frequencies unless made very thick.

The purpose of implementing low-frequency traps is to achieve a more even and accurate sound reproduction, especially crucial in listening rooms, recording studios, and home theaters. By reducing problematic resonances, they can improve clarity, bass definition, and the overall listening experience. The effectiveness of a low-frequency trap is dependent on its size, construction, and precise tuning to the specific problematic frequencies within a given space.