Between the end points, an analog EQ will have a series of vertically-oriented (up-and-down) adjustment sliders. A digital EQ will have a series of marked points spaced out along the horizontal line. These sliders or control points are often set at 30 Hz, 100 Hz, 1 kHz, 10 kHz, and 20 kHz. Some models allow you to alter these control point settings, while others are permanently fixed at these frequencies.
With a digital EQ, you typically click on a control point and drag up to boost or down to cut. For example, if you wanted to boost audio in the 100 Hz frequency range, you’d either push the 100 Hz slider upward (analog) or click and drag it upward (digital). Or, to cut the 1 kHz frequency range, you’d slide or click and drag down below the horizontal line.
A low pass filter and high pass filter. A low pass filter lets all frequencies below a certain point “pass through” and blocks all frequencies above that point. A high pass filter does the opposite. For example, you could use a low pass filter to block all frequencies above 10 kHz. Q-range adjustments. When you boost or cut a particular frequency, it also impacts surrounding frequencies to lesser degrees—for instance, boosting 100 Hz also boosts 75 Hz and 125 Hz to lesser amounts. Decreasing the Q-range reduces this surrounding impact, while increasing it enhances it.
By selecting a preset, the various frequency control points will be “boosted” or “cut” to levels that are considered ideal for a particular type of music or audio. Presets provide a quick way to improve the sound of the audio coming through your headphones, earbuds, or speakers. Analog EQs don’t usually have presets, since you have to manually adjust the sliders yourself.
The ultimate goal for EQ adjustments is to make the audio sound as perfect as possible to your ears—so trust them! If your ears tell you that the bass needs boosted, adjust the lower frequencies no matter what the presets indicate.
For example, you may find that adding a new carpet and couch to your den alters how the “jazz” preset sounds on your home stereo. You may have to do some tinkering to get the sound just right once again.
Boosting is more likely to add distortions to the audio, especially if you boost a particular frequency range to a significant degree. Cutting is far less likely to cause distortions. So, to crank up the bass at 100 Hz, leave it at neutral (or only slightly boosted), and cut the sub-bass at 30 Hz and mid-range sounds at 1 kHz.
These apps usually start by giving you a short “hearing test” to determine how well you pick up different frequency ranges. It will then create custom-made presets that will automatically adjust based on the type of audio and other factors. If you just want your music to sound “pretty good” whenever you put in your earbuds, this may be the best option for you.
Female vocals: 150 Hz-1. 6 kHz Male vocals: 60 Hz-500 Hz Saxophone: 100 Hz-700 Hz Guitar: 70 Hz-1. 1 kHz Cymbals: 200 Hz-10 kHz Kick drum: 60 Hz-4 kHz Piano: 25 Hz-4. 5 kHz
You may have to do some searching by trial-and-error to find the instrument or vocal you’re looking to highlight, but keep at it—you will find it! As an example, you might boost the 100 Hz setting in search of an electric guitar, and find that it helps to boost the 1 kHz setting as well.
In other words: if you want to highlight the electric guitar, it’s better to “cut” the drums, saxophone, and vocals than it is to “boost” the electric guitar significantly. Large “boosts” tend to cause audio distortions, which isn’t a problem with “cuts. ”
Q-range is easier to visualize with a digital EQ. In this format, a boosted setting looks like a triangle, with the apex representing the amount of the boost and the sloping sides representing the lesser boosting occuring at other surrounding frequencies. Narrowing the Q-range makes the triangle “skinnier,” which means fewer surrounding frequencies are impacted; increasing Q-range does the opposite.
