Understanding Studio Monitors: Working with Bass Frequencies and Diffusion
Learn how to create and place bass traps, diffusers, and more
Dealing with Bass Frequencies

Uneven bass response can be a major problem for many project studio owners. Bass frequencies tend to build up in corners and boundary points, so the central listening position often suffers from a lack of bass clarity. Bass frequencies behave differently than mids and highs, so treating the room for low‑end response requires unique methods. Materials that absorb high frequencies often provide little resistance to the low‑frequency end of the spectrum (and vice versa). In order to properly handle low frequencies, most rooms need to be controlled with bass traps.

Bass traps employ special absorptive materials that reduce the resonance of low frequencies. You can absorb a large portion of undesired bass frequencies by placing these devices in corners, room boundaries or free‑standing spots.

Tip: You can make an inexpensive, temporary bass trap by wrapping layers of carpet and/or carpet padding around a framework of suitable size, such as a bookcase or wooden frame. Mounting the frame on wheels allows easy positioning.

Diffusion

If your room is rather small (less than 10’ x 10’), you can achieve good results using a few carefully placed absorptive panels. For larger rooms however, you may need sound wave diffusers. Diffusers are acoustical boundaries or panels that reflect the sound wave back at various angles, thereby breaking up the troublesome standing waves. Diffusers can be attached to the wall and/or ceiling boundaries—helping to redirect reflections away from the central listening position. Using diffusion can reduce a condition known as flutter echo and can smooth out the reverberation characteristics of a room by building further and more complex acoustical pathways (See figure 8).


Tip: You can diffuse sound waves by setting up a wall of tall bookcases filled with absorbent and irregularly shaped objects (See figure 7).