Bassfalle

Bassfalle is the German term for a bass trap in acoustics. It refers to a device or construction designed to reduce low-frequency energy in enclosed spaces. By absorbing or dampening standing waves and room modes, bassfalle helps flatten the bass response and reduce excessive rumble in rooms used for music playback, mixing, or listening.

Low frequencies have long wavelengths that interact with room boundaries to produce peaks and dips in the in-room response. Bassfalle are placed in locations where pressure is high, typically in vertical corners (where two walls meet) and sometimes along parallel walls or ceiling corners to address axial, shear, and tangential modes. In small rooms, multiple bass traps may be required.

Types include: porous absorbers such as thick fiberglass or mineral wool panels; Helmholtz resonators and other tuned resonators; and panel or membrane-based traps that vibrate and dissipate energy. Porous absorbers are broadband but require substantial thickness to affect the lowest frequencies; tuned resonators are more efficient at specific frequencies (often in the 40–200 Hz range). Corner bass traps combine several panels or cubes to increase low-frequency absorption, particularly in three-dimensional corners.

Design and evaluation typically involve room measurements or standards such as RT60 or spectral analysis to identify problematic modes, followed by iterative placement. Overabsorption at very low frequencies can make a room sound dull, so bass trapping should be balanced with midrange treatment and spatial considerations.

Common practical implementations include fabric-covered fiberglass or mineral wool blocks placed in room corners, sometimes with air gaps to improve performance, and modular foam or wood-panel panels for aesthetic integration.