Bass Trap

A bass trap is an acoustic treatment device specifically designed to absorb low-frequency sound energy, typically below 300 Hz. Bass traps address the room modes and standing waves that cause uneven bass response in small to medium rooms. Common types include thick porous absorbers placed in corners (where bass pressure is highest), membrane/panel absorbers tuned to target frequencies, and Helmholtz resonators. Corner-mounted porous bass traps (300–600 mm thick mineral wool or fiberglass) provide broadband bass absorption and are the most common treatment in recording studios and control rooms. Effective bass trapping requires significant depth or mass because low-frequency wavelengths are long (2.7 m at 125 Hz). Bass traps are essential in any critical listening environment and are typically the first treatment installed after measuring the room’s modal response.