Understanding frequency bands can be a difficult thing to comprehend. However, when it comes to equalization, knowing the frequency bands is a must. In this blog I will describe the different ranges that each band covers and what can be achieved by manipulating each band. First let me say that frequency is measured in Hertz (hz). The human ear can only distinguish sounds within the range of about 20 hz – 20,000 hz or 20 KHz. To be able to distinguish between these regions and what type of sound they create required practice and lots of it. The only way to become great at equalization is by training your ear and the only way to train your ear is to practice, practice, practice. Watching video tutorials is one great way to train your ear because you can be told what frequency range is being affected as you hear it. This can be great because it eliminates any doubt or confusion about whether or not you have been able to distinguish each region effectively. Many charts and tools can be found online that describe the bands and their regions. This information was taken from Hal-bar.com and I chose this in particular because it so well describes each region and what sounds are found within them. Below these descriptions of each frequency band you will find a very detailed chart that is a very useful tool for aspiring engineers.
120Hz and lower: these frequencies are generally responsible for warmth in a recording. Too much and the recording will sound muddy.
120Hz – 600Hz: these frequencies give depth to a recording, giving vocals and other instruments a strong sense of presence without being clinical. On the other hand, these frequencies are where you’re most likely to experience problems with vocal resonance. Too much in this area can be particularly fatiguing.
600Hz – 3kHz: these frequencies also give presence but of a generally harder nature. High output in this region is fairly common in rock music as it gives it a hard edge that suites the genre.
3kHz- 7kHz: is the area where vocal sibilance resides. 3kHz-5kHz is a very common peaking area in rock music because human hearing is pretty sensitive here and extra output here makes it sound louder. It also adds a harshness that is particularly fatiguing so don’t over do it. Because of the high sensitivity in this region you can add warmth without loss of clarity by attenuating this region a bit.
7kHz -: Cymbals etc, and all the other components that add the sense of quality and accuracy. Above 10kHz too much output may make your recordings sound like they are lacking some definition.
If your tracks lack warmth and have too much sibilance you either have too little output below 500Hz or too much above 3kHz. A generally good balance will be pretty flat from around 60Hz up to 1-2kHz and then rolling off to be around 10-20 dB down at 10kHz. How much tapering at the spectrum ends you’ll need will depend on the nature of the music.
If there are some sharp peaks in the peak spectrum that stand out above the rest then they may need to be attenuated a bit. Again, don’t try to eliminate the peak but just reduce and control it a bit. A good rule of thumb would be to reduce the peak so that it is about as high as the other undulations on the spectrum.
Finally, strong output in the region of 3-5kHz can make recordings sound fatiguing and clinical. If you have strong output in this region reduce it by approximately 3dB.
This is a good starting point for a new engineer but like I’ve said before the only way to truly be able to distinguish the regions and their unique sound is to put this information into action and practice, practice, practice.