Even though an engineer has every intention of making his tracks sound as big and as clear as possible when recording basic tracks and overdubs, the frequency range of some or all of the tracks ends up being somewhat limited when it comes time to mix. This can be because the tracks were recorded in a different studio using different monitors, a different signal path, or just how things in the studio can change from day to day and from musician to musician. As a result, the mixing engineer later must extend the frequency range of those tracks when it comes time to put it all together at mixing time.
In the quest to make things sound bigger, fatter, brighter and clearer all at the same time, the equalizer is the chief tool used by most mixers. But perhaps more than any other audio tool, the use of the equalizer requires a subjective skill that separates the average engineer from the master.
What Are You Trying To Do?
So exactly what are you trying to do when you insert an equalizer into the signal path? There are three primary goals when equalizing:
- Make an instrument sound clearer and more defined.
- Make the instrument or mix bigger and larger than life.
- Make all the elements of a mix fit together better by juggling frequencies so that each instrument sits in its own predominate frequency range.
Sometimes you’re trying to achieve only one of the above goals, but most of the time (especially if you’re mixing music) you’re trying to achieve all three.
Important Frequency Ranges
Before we examine some methods of equalizing, it’s important to note the areas of the audio band and what effect they have on what we hear. The audio band can effectively be broken down into six distinct ranges, each one having an enormous impact on the total sound.
- Sub-Bass - The very low bass between 16 and 60Hz which encompasses sounds which are often felt more than heard, such as thunder in the distance. These frequencies give the music a sense of power even if they occur infrequently. Too much emphasis on this range makes the music sound muddy.
- Bass - The bass between 60 and 250Hz contains the fundamental notes of the rhythm section so EQing this range can change the musical balance, making it fat or thin. Too much boost in this range can make the music sound boomy.
- Low Mids - The midrange between 250 and 2000Hz contains the low order harmonics of most musical instruments and can introduce a telephone like quality to the music if boosted too much. Boosting the 500 to 1000Hz octave makes the instruments sound horn like, while boosting the 1 to 2kHz octave makes them sound tinny. Excess output in this range can cause listening fatigue.
- High Mids - The upper midrange between 2 and 4kHz can mask the important speech recognition sounds if boosted, introducing a lisping quality into a voice and making sounds formed with the lips such as ‘m”, “b,” and “v” indistinguishable. Too much boost in this range, especially at 3kHz, can also cause listening fatigue. Dipping the 3kHz range on instrument backgrounds and slightly peaking 3kHz on vocals can make the vocals audible without having to decrease the instrumental level in mixes where the voice would otherwise seem buried.
- Presence - The presence range between 4 and 6kHz is responsible for the clarity and definition of voices and instruments. Boosting this range can make the music seem closer to the listener. Reducing the 5kHz content of a mix makes the sound more distant and transparent.
- Brilliance - The 6 to 16kHz range controls the brilliance and clarity of sounds. Too much emphasis in this range, however, can produce sibilance on the vocals.
Leo di Gar Kulka - “Equalization…….The Highest, Most Sustained Expression of the Recordist’s Heart”, Recording engineer/producer, Vol. 3, Number 6, November/December 1972
It should be noted that not all instruments need to contain all of these frequency ranges, but it’s important to know each range and exactly how it influences your source audio.
If we break the above down into a simple chart, it looks like this.
The Magic Frequencies
If we break down the frequencies ranges into smaller octave elements, we come up with what I call the “magic frequencies,” since all of your frequency decisions revolve around them.
Since each specific song, instrument, and musician is unique, it’s impossible to give anything other than some general guidelines as to equalization methods. Also, different engineers have different ways of arriving at the same end, so if the following doesn’t work for you, keep trying. The method doesn’t matter, only the end result.
Before we go into these methods, it’s really important that you observe the following 2 principles:
LISTEN!! Open up your ears and listen carefully to all the nuances of the sound.
Everything you hear is important, but you have to tune your ear listen to the nuances. Listen for the attack and release of the sound. Is there any distortion, either natural or artificially induced? Is there any noise? What’s the ambience around the sound like? Is there a frequency that jumps out?
Make sure you’re monitoring at a comfortable level; not too loud and especially not too soft.
If it’s too soft, you may be fooled by the non-linearity of the speakers, overcompensate and add too much. If it’s too loud, certain frequencies may be masked or overemphasized by the non-linearities of the ear itself (thanks to the Fletcher-Munson curves) and again you will overcompensate.
I mixed for years at levels that were too low, and my mixes came out well balanced but kind of on the wimpy side. It wasn’t until I cranked it up somewhat that my mixes started to have the fullness and drive that I was looking for. After you get the sound you’re looking for, it’s best to turn it down to check the balances and limit your ear fatigue. Believe it or not, there are a lot of different ways that top mixers prefer to listen (including over the din of a vacuum cleaner, if you can believe that) - enough that we’ll dedicate a full post to in the future.
The EQ Methods
OK, let’s move on to the different ways of EQing.
EQ Method 1
Equalize to make an instrument sound clearer and more defined.
Even some sounds that are recorded well can be lifeless thanks to certain frequencies being overemphasized or others being severely attenuated. More often than not, the lack of definition of an instrument is because of too much lower midrange in approximately the 400 to 800Hz area thanks to the proximity effect of directional microphones. This area adds a “boxy” quality to the sound and cutting it a bit can really add to the clarity of an instrument without having to do much more.
That being said, here’s a method for improving the clarity of sound that really works:
- Set the Boost/Cut knob to a moderate level of CUT (8 or 10dB should work, although some engineers turn the knob as far as it will go).
- Sweep through the frequencies until you find the frequency area where the sound has the least amount of boxiness and the most definition.
- Adjust the amount of cut to taste. Be aware that too much cut will cause the sound to be thinner.
- If required, add some “point” to sound by adding a slight amount (start with only a dB or two; add more to taste) of upper midrange (2 to 4kHz).
- If required, add some “sparkle” to the sound by adding a slight amount of high frequencies (5 to 10kHz).
- If required, add some “air” to sound by adding a slight amount of the brilliance frequencies (10 to 15kHz).
PLEASE NOTE: Always try attenuating (cutting) the frequency first. This is preferable because all equalizers add phase shift as you boost, which can result in an undesirable coloring of the sound. Usually, the more EQ you add, the more phase shift is also added and the harder it will be to fit the instrument into the mix. Many engineers are judicious in their use of EQ.
That being said, anything goes! If it sounds good, it is good. As platinum mixer and owner of the famous Oceanway recording studio Allen Sides says,
“I tend to like things to sound sort of natural but I don’t care what it takes to make it sound like that. Some people get a very preconceived set of notions that you can’t do this or you can’t do that. Like Bruce Swedien (Michael Jackson’s engineer) said to me, he doesn’t care if you have to turn the knob around backwards; if it sounds good, it is good. Assuming that you have a reference point that you can trust, of course.”
Alternate Method 1
- Starting with your EQ flat, remove ALL the bottom end by turning the low frequency control to full cut.
- Using the rest of your EQ, tune the mid-upper midrange until the sound is thick yet distinct.
- Round it out with a supporting lower-mid tone to give it some body.
- Slowly bring up the mud-inducing bottom end enough to move air, but not so much as to make the sound muddy.
- Add some high frequency for definition.
EQ Method 2
Equalize to make the instrument or mix bigger and larger than life.
“Bigness” usually comes from the presence of bass and sub-bass frequencies in the 40 to 250Hz range. That being said, the frequencies that make your sound big actually come from several frequency regions at once - a region below 100Hz and a region above 100Hz. As a result, it’s sometimes easier to use EQ Method 2 to achieve the results you’re looking for.
- Set the Boost/Cut knob to a moderate level of BOOST (8 or 10dB should work).
- Sweep through the frequencies in the bass band until you find the frequency where the sound has the desired amount of fullness.
- Adjust the amount of Boost to taste. Be aware that too much Boost will make the instrument sound muddy.
- Go to the frequency either 1/2 or twice the frequency that you used in B and add a bit of that frequency as well. Example: If your frequency in B was 120Hz, go to 60Hz and add a dB or so as well. If your frequency was 50Hz, go to 100 and add a bit there.
- It’s usually better to add a small amount at two frequencies than a large amount at one.
- Be aware that making an instrument sound great while soloed may make it impossible to fit together with other instruments in the mix.
EQ Method 3
Equalize to make all the elements of a mix fit together better by juggling frequencies so that each instrument has its own predominate frequency range.
Start with the rhythm section (bass and drums). The bass should be clear and distinct when played against the drums, especially the kick and snare. Each instrument should be heard distinctly. If not, do the following:
- Make sure that no two equalizers are boosting at the same frequency. If so, move one to a frequency a little higher or lower than the instrument it’s competing against.
- If an instrument is cut at a certain frequency, boost the frequency of the other instrument at that same frequency. Example: If the kick is cut at 500Hz, boost the bass at 500Hz.
- Add the next most predominate element, usually the vocal and proceed as above.
- Add the rest of the elements into the mix one by one. As each instrument is added it should be checked against the previous elements as above.
- The idea is to hear each instrument clearly and the best way for that to happen is for each instrument to live in it’s own frequency band.
- After frequency juggling, an instrument might sound terrible when soloed by itself. That’s OK. The idea is for it to work well in the track.
- You will most likely have to EQ in circle where you start with one instrument, then tweak another that’s clashing, then return to the original one, and back again over and over until the desired separation is achieved.
The Relationship Between Bass And Drums
Perhaps the most difficult task of a mixing engineer is balancing the bass and drums (especially the bass and kick). Nothing can make or break a mix faster than how these instruments work together. It’s not uncommon for a mixer to spend hours on this balance (both level and frequency) because if the relationship isn’t correct, then the song will just never sound big and punchy.
So how do you get this mysterious balance?
In order to have the impact and punch that most great modern mixes exhibit, you have to make a space in your mix for both of these instruments so they won’t fight each other and turn into a muddy mess. While simply EQing your bass high and your kick low (or the other way around), might work at it’s simplest, it’s best to have a more in-depth strategy. To make them fit together, try the following:
EQ the kick drum between 60 to 120Hz as this will allow it to be heard well on smaller speakers.
For more attack and beater click, add a little between 1 and 4kHz. You may also want to dip some of the boxiness between 300-600Hz. EQing in the 30-60Hz range will produce a kick that you can feel but it may also sound thin on smaller speakers and probably won’t translate well to a variety of speaker systems. The fundamental of most 22″ kick drums (which is the most used size) is centered somewhere around 80Hz.
With the bass and kick soloed, they should occupy slightly different frequency spaces.
The kick will usually be in the 60-80Hz range whereas the bass will emphasize higher frequencies anywhere from 80 to 250 (although sometimes the two are reversed depending upon the song). Shelve out any unnecessary bass frequencies so it doesn’t sound boomy or muddy. That means the frequencies below 30Hz on kick and 50Hz on the bass, although it will vary according to the style of music and your particular taste. The end result should be a driving, foundational quality to the combination of these two together.
A common mistake is to emphasize the kick with either too much level or EQ and not enough on the bass guitar. This gives you the illusion that your mix is bottom light, because what you are doing is shortening the duration of the low frequency envelope in your mix since the mix is now centered around the kick. The kick envelope is more transitory than the bass guitar, so too much kick can give the ear the idea that the low frequency content of your mix is inconsistent. For Pop and Rock music, it’s best to have the kick provide the percussive nature of the bottom while the bass fills out the sustain and musical parts.
Make sure the snare is strong, otherwise the song will lose its drive when everything else is added in.
This usually calls for at least some compression (which we’ll cover in detail in a future post). You may need a boost at 1k to 2k for attack, 120 to 240Hz for fullness, and 10k for snap. You might want to dip a little 1k on the other drums to make a little more room for the snare. Also make sure that the toms aren’t too boomy. If so, shelve out the frequencies below 60 Hz on them.
If you’re having trouble with the mix because it’s sounding cloudy and muddy, turn the kick drum and bass off to determine what else might be in the way in the low end.
You might not realize that there are some frequencies in the mix that aren’t really musically necessary. With piano or guitar, you’re mainly looking for the mids and top end to cut through, so the low-end just gets in the way of the bass and drums. As a result, it’s best to clear some of that low end out with a hi-pass filter. When soloed, the instrument now might sound too thin, but with the rest of the mix the bottom will sound so much better, and you won’t really miss that low end from the other instruments. Now the mix will sound louder, clearer, and fuller. Be careful not to cut too much from the other instruments though, as you might loose the warmth of the mix.
For Dance music, be aware of any kick drum to bass melody dissonance.
The bass line over the huge sound systems in today’s clubs is very important and needs to work very well with the kick drum. But if your kick is tuned to a frequency that peaks on an A note and the bass line is tuned to A#, it’s going to clash. Tune your kick samples to the bass lines (or vice versa) where needed.
EQing is so subjective that it’s hard to break down to a science. Don’t get frustrated if you don’t feel that you have a handle on the process because it’s truly one of the hardest processes to grasp in recording. It can really take a long time if you stumble along without any guidance. That being said, if you follow any of the above-mentioned tips, with a little practice you’ll find that your mixes will become fuller, more powerful and better defined. Good luck!