Bass Traps

Bass traps are devices that improve the response of the low frequency in a room. Sound engineers and music producers often employ them to lessen this low-frequency resonance. They also use them in large studios and small spaces to flatten the low-frequency response. In addition, they take advantage of them to decrease modal ringing.

Bass Traps: How They Work

They work by reducing peaks, raising nulls, and reducing modal decay lines. Specifically, they control peaks and nulls, which transforms any space in a much more consistent environment. Small spaces don’t have a true reverberation below their Schroeder frequency. This is because, usually, the ringing at individual mode frequencies dominate. In contrast, in large spaces such as auditoriums and large studios, these traps are essential for reducing the low-frequency resonance.

The Categories of Bass Traps

Bass traps can fall under two categories: broadband versus tuned and pressure versus velocity. 

On the one hand, porous materials are typically broadband and act on velocity. On the other, pressure absorbers tune to a specific frequency. Most rooms benefit from broadband bass traps because peaks and nulls happen at low-frequencies. Moreover, the dimensions of the room don’t affect them.

Tuned bass traps are common on ranges above one octave. They are highly effective over ranges of half an octave or less. This kind, in combination with broadband ones, can solve frequency issues that porous absorbers can’t handle.

Make the Best of Them

Porous materials build bass traps. A popular example is rigid fiberglass, although the preferred material for tuned ones are wood and vinyl sheets. Rigid fibreglass is the standard for inside the pressure traps to add damping.

It’s essential for you to position bass traps in specific places of a room. Corners are the most efficient points. The reason behind this decision is that low-frequency resonances in space have their points of maximum or minimum pressure in the corners. Theyusually combine structural mechanisms that work at both positions of high particle velocity/low pressure, as well as high pressure/low particle velocity. 

Foam wedges are a type of bass trap that is easily available to the public. However, this option isn’t that efficient when it comes to the absorption of low-bass frequencies.