Setting a seven-band equalizer can seem like a difficult task, especially if you have no audio training and are unsure of which frequencies control what sounds. However, once you learn the basics, using an equalizer to correct sound becomes much clearer. Equalizers are traditionally used to flatten sounds, although in the latter part of the 20th century, equalizers have been used to help consumers and audio professionals to create the sounds they want to hear in their particular environment or recording.
Learn what the seven bands control before beginning to set your equalizer. Most seven-band equalizers have a 60Hz band, a 150Hz band, a 400Hz band, a 1 kHz band, a 2.4 kHz band, a 6 kHz band and a 15 kHz band. These bands move from low frequency to high frequency, with 60Hz representing the very low end of the spectrum and 15 kHz representing the extremely high end of the spectrum.
Try to decrease frequencies to achieve the sound that you want instead of increasing them. Increasing a frequency can often cause distortion or unnatural sound, while decreasing a different frequency may have the same relative effect on the source material. For example, if you want to hear more mid-range sounds in the recording you are listening to, it may be preferable to reduce or cut the 60Hz and 150Hz band in the low end, and the 15 kHz and 6 kHz band in the high end. This will make the mid-range more present in the recording being listened to.
Check to make sure you have not created any distortion after equalizing the audio. While most distortion is only a concern if it is audible, distortion can be present when it cannot be heard. Many equalizers have a volume output meter on the front panel display that will show you the volume of the audio as it is received, and how it is output through the equalizer.
Listen to a wide variety of music in the space you are in to see if you encounter general problems. For example, many rooms with a square shape tend to have an excessive bass buildup, and a reduction of the 60Hz frequency is generally sufficient to reduce the buildup. Always diagnose the problem of your particular room before making rash changes that may make listening less pleasant.
Purchasing a series of test-tones can be a great way to test the frequency response of your room. Generally, these tones will be the same volume, although they may appear louder or quieter in your particular listening space. Knowing where your room has a deficiency or buildup of frequencies is an effective way to determine how to best set your equalizer.