Audio Recording with Equalizers – 10 Equalizer Modes – Part Nine – Band or Bell-Shaped EQThe Band or Bell-Shaped EQ is one of the most important and common EQ modes available today. The Band mode denotes a single location on the EQ spectrum. It begins and ends at the intersection of 0dB Gain. The width of the Band EQ is determined by the “Q” width setting. The Band EQ runs at a distance from its first point, which is the lowest Frequency of the Band, to the second point, the highest Frequency of the Band. When adjusting the Band EQ Gain, it selects the very center point of the Band In most cases. The typical Band EQ is symmetrical, so its central point is selected from minimum to maximum boost and cut Gain points. Typically, Gain can be selected from +/-10dB, but we often see as much as +/-12dB and even +/-16-20dB. The wider the range of Gain, the more potential there is for variability in its response. Sharp “Q” width slopes tend to be steeper and more resonant than smooth narrow shapes and much more than wide “Q” width.
Most Band EQ options are called Bell-Shape EQ. As you might guess, this is named for the height and smooth shape at the peak Gain of the Band EQ. This is usually the most visually consistent at moderate “Q” settings. The more narrow the “Q” setting, the sharper the tip will become. Some Band EQ's are sharper in narrow “Q” and some tend to maintain the same Band shape. Most Band EQ's have a lower range of Gain at their wider settings. The Bell-Shape will be extremely gradual and smooth and the peak levels may be as little as half the amount when they are at the narrowest setting.
It is possible, depending on the intention of design, that the Band EQ is not symmetrical when comparing boost Gain and cut Gain. Some Band EQ's are designed to be a perfect mirror image at positive and negative Gain settings. If these EQ's are plotted on a graph so that you can see all settings and Gain at once, it will look like a perfectly symmetrical oval shape. Other Band EQ's are designed to have a rounder, wider, smoother Bell-Shape when given boost Gain and a sharper, narrower, deeper cut Gain. This is seen as making smooth additive changes that are sonically pleasing and making cuts that are more corrective and affect less of the surrounding Frequencies.
Some Band EQ's are not symmetrical from the edges to the peak or central point. These are rare in comparison, but they can give the user a very unusual and unique creative control that otherwise does not exist. These EQ's tend to have a regular initial distance from point to point, but as Gain is increased beyond a few decibels, there is a curve to the center point, much like a hook or claw. This allows the ability to gently boost or cut a center point and then reduce more from the Frequency just above center. As the point sharpens above the center, there is the increasing ability to cut a very narrow amount of corrective EQ.
When using Band EQ's, I recommend testing out various settings. If the Frequencies are fixed, get to know what it sounds like at boost and cut, and at the steepest settings, to learn if it becomes more subtle and narrow as the Gain is increased or if it remains fairly curved and more audible. If your Band EQ is adjustable in “Q” width, test it out on different material to get used to its affect at different widths. There is always more to the affect of an EQ than the visualization of its shape, so listening is the key to becoming familiar with its individual personality. You will find that you lean more towards some settings over others, and this will help you to develop your personal mixing or mastering style.