Thefact that every professional mixing console comes with an equalizer oneach channel speaks volumes about the importance of EQ in the recordingand mixing process. Mixing a record without EQ would be prettydifficult: we'd be forced to rely on capturing a pristine performancefrom a perfectly tuned instrument, in an acoustically correct room,using expensive and accurate microphones that are properly placed inrelation to the sound source. How often does that happen?
So we have an arsenal of tools to help compensate, and EQ isarguably the most important one. But although every console has EQ, andmost studios offer some sophisticated outboard units, not everyengineer knows how to properly equalize a sound. Let's correct thatproblem by discussing the basics of EQ and the different types ofequalizers and when they're traditionally employed. I'll also offersome specific applications that you may find useful when tracking ormixing your project.
THE GOAL OF EQ To get some outside input, I called on twoprofessional audio engineers from New York City. Derek Martin (whohastens to point out that he is no relation to Sir George) is afreelance music engineer who floats around the Big Apple, hittingstudios such as Quad Recording, Waterfront Sound, and Apex Recording.His resume is impressive, with credits ranging from Kool and the Gangto Nine Inch Nails. Greg Petricelli works at Midtown Digital andspecializes in audio for video. He recently completed work oncommercials for Nike and IBM. These two engineers provided valuableinsights into how equalization is approached in differentapplications.
Before we can talk about specific applications, though, we have toask the basic question: what's your ultimate goal when using the EQprocess? Petricelli notes, "The purpose for using an equalizer is tochange the frequency content of a signal. However, the reasons forchanging the content vary. Usually it's to coax the very best sound outof an instrument."
In most cases, though, an instrument that sounds great by itselfalso needs to fit into the context of a mix. "Getting a track to blendin a mix so that its frequency response doesn't interfere with anyother tracks is the very goal of the mixing process," says Petricelli."Usually you want to eliminate frequencies that aren't needed by thatparticular instrument." But, Martin is quick to add, "oftentimes you'lluse EQ to get a track to stand out in a mix, above the rest of thetracks-like a vocal, for example."
You can also use EQ to fix minor flaws present in a signal. Forexample, a 60 Hz AC hum can be notched out of an electric-guitar track,or you can use a de-esser to filter out unwanted sibilance in a vocaltrack. Although many sound designers use EQ creatively to sculpt soundsinto new and different ones, for the purposes of this article we'llfocus on how to use EQ within the context of a mix, be it for a musicCD or a television commercial.
ALL SHAPES AND SIZES Equalizers are essentially filters, althoughthey can often boost as well as attenuate signals. Both active andpassive EQs are available, and some products use a combination of thetwo designs (for example, passive high and low shelving bands andactive mid bands). Active EQs traditionally employ op amps to boost andcut frequencies. Most console EQs are active, as are most outboard EQsexcept for a handful of high-end processors.
Passive filters cost much more than active ones and are, therefore,not commonly found in personal studios. They traditionally use coils orcapacitors to attenuate frequencies; strictly speaking, they neverboost. The tone controls on most guitars, for example, are passivefilters. However, a passive EQ may have an amplification stage beforeor after the filter (or both). That means you can effectively boost afrequency band by cutting everything on both sides of it and amplifyingthe overall signal before or after cutting.
The most common, and the most useful, studio equalizer is theparametric EQ. A true parametric EQ affords you control over threeparameters: gain, frequency, and bandwidth or Q (see Fig. 1). Untilrecently, most parametric EQs were outboard units, but many digitalmixers now use them, as well.
Quasi-parametric EQs have gain and frequency controls but only alimited number of preset bandwidths. Just as common is thesemiparametric, or midsweep, EQ. Semiparametric EQs have gain andfrequency controls but no bandwidth control.
Shelving EQs work at either end of the frequency spectrum,attenuating or boosting all frequencies above or below a specificcutoff, or knee, frequency. These equalizers are so named because thegraph of frequency and amplitude looks like a shelf (see Fig. 2).Shelving EQs typically offer gain and frequency controls. There isusually a preset rolloff that gradually slopes from the knee frequencyto the shelf; however, some of the more elaborate units available allowyou to adjust this ratio.
The channel strips on many analog consoles have high and lowshelving filters and a midrange bandpass filter with sweepable centerfrequency. Lower-cost mixers often have shelving filters for the highsand lows and one fixed-frequency bandpass filter for the mids. Someconsoles also offer a "rumble filter," which is a low-cut shelvingfilter with a preset cutoff frequency.
Graphic EQs, although commonly associated with home audio equipmentand P.A. systems, are also useful in the recording studio. Graphicequalizers divide the frequency spectrum into a number of evenly spacedbands with fixed bandwidths and with gain controls for each band. Theresult is a number of fixed-bandwidth bell curves that can be boostedor attenuated as needed (see Fig. 3). Graphic EQs are usually used to"tune" the monitoring system. There are times, however, when you mightwant to patch in a graphic EQ on a track so that you can play withseveral frequency bands simultaneously (more on this later).
EQ ETIQUETTE Although most people prefer to EQ during mixdown, someinsist on equalizing during tracking. Martin, Petricelli, and I agreethat dramatically changing an instrument's frequency content prior torecording is usually not the best approach. "You want the instrument tosound natural and good going to tape," Martin explains, "and thisinvolves a whole number of things. For example, you have to make surethat the instrument is a quality instrument that's tuned properly; asthey say, 'garbage in, garbage out.' You also have to make sure you'vemiked the instrument properly, with the right capsule and from theright angle. But aside from that, I see no benefit in making sonicchanges at this point; you're not going to know what you need to tweakuntil you hear the track in context with the other tracks."
However, Petricelli also points out that there may be certaininstances when you want to address a problem before the signal getsprinted. "If I had a high-frequency buzz coming through an amp," hesays, "I would certainly want to get rid of it before recording-and ifthat meant using a notch filter, then so be it. It's less to worryabout later."
That brings up the issue of adjusting the EQ on instrument amps.Both engineers agree that this falls into the category of tuning aninstrument. "You wouldn't leave an out-of-tune tom-tom to be fixed inthe mix with EQ," Petricelli points out, "so I see no reason why thatdoesn't apply to a poorly equalized guitar amp." Martin says,"Obviously you'll also be tweaking the amp track's EQ in the mix, butyou still want that amp to sound great in the room, with the mic onit."
Another debate that inevitably arises is whether additive orsubtractive EQ benefits a mix more. In certain instances only oneapproach would be appropriate; for example, using a highpass filter toroll off everything below 40 Hz is definitely a necessary applicationof subtractive EQ-there's no other way to go. But some stalwarts(especially jazz and classical engineers) take a more extreme position,insisting that nothing should be added if it isn't there already. Theseengineers use only subtractive filters. On the other hand, some rockand pop engineers simply turn up the knobs until they like thesound.
Most engineers, however, combine both philosophies and use whateverapproach works best for the situation at hand. Petricelli explains: "Iusually start equalizing using a subtractive approach, turning down thegain of a parametric EQ and sweeping the frequency knob until I hearsomething that needs to come out. As soon as I do that, though, I mayrealize that I need to add a few decibels at a higher frequency tocompensate. I'll then repeat the process, with the gain of another bandturned all the way up, sweeping the frequency knob."
FOURTEEN EQ TIPS Now that I've discussed some basic principals of EQand the various types of equalizers, let's look at some specific EQapplications and the ways in which you can approach each. Most of thesetips require at least a 3-band parametric equalizer.
Because drums are usually the hardest instruments to equalize, I'vedevoted some space to them. We'll start with the percussioninstruments; work our way through string, wind, and horn instruments;and finish with the human voice and special applications. Keep in mindthat you can apply these tips to digital samples, as well as toacoustic instruments.
1. KICK DRUM A kick drum is one of the most important components ofany mix, because it drives the beat (assuming you're not working with achamber orchestra). But you must determine the type of character youwant that beat to have.
First, you need to listen to the sound of the drum as captured bythe microphone. This approach is imperative for any EQ application-youshould always listen before you tweak. If the kick has a naturallyhollow tone and is tuned correctly, you have a bit of room to maneuver.If the drum is padded and produces more of a "thud," your options aremore limited, although you can still dial in a number of "kicking"sounds. Remember, if you're lucky enough to be involved in the entirerecording and mixing process, you have the liberty to go back in thechain and make desired changes (like removing a muffler from a kickdrum); if you're simply mixing a project, however, you must work withwhat you have.
Here we'll discuss three specific kick-drum sounds, all of which youcan dial in if you have a track with an unpadded kick drum. Althoughthese tips give you good starting points, you'll need to make tweaksbecause each drum is different. The first sound I call the '80s BigHair Kick Drum. You know the sound: punchy, with lots of midrange and abit of a thump.
Petricelli describes how he typically obtains this somewhat datedsound. "If you have a 4-band parametric EQ," he relates, "you start byrolling off everything below 60 Hz. This will eliminate rumble. Movingup one band, boost between 78 and 84 Hz by 3 to 6 dB, with about a 1.0Q factor. Again, you may need more or less, depending on your track.This will provide the kick that hits you right in the chest. Next, dialin the punchiness between 1.5 and 2.5 kHz, boosting by about 6 dB.Here, a bandwidth of 1.5 to 2.5 should work nicely. Finally, notch out120 Hz by about 4 dB with a 1.0 Q setting. Play with the parametersuntil your kick drum sounds like a White Lion record. If you have onlya midsweep EQ with high and low shelving bands, try boosting the midsaround 2 kHz by about 6 dB, turn the high shelf up between 4 and 6 dB,and boost the low shelf by about 2 dB."
Although this sound was popular in the 1980s, today we've returnedto our roots, and engineers usually strive for a classic rock kick-drumsound, a la John Bonham. "The Bonham kick drum is the quintessentialrock drum sound," Martin explains. "I usually obtain it by boosting thefrequencies between 120 and 240 Hz by about 4 dB or more. You'll alsoneed to roll off everything above 1.5 kHz. Sometimes, depending on thedrum, you also might want to notch out 80 Hz a bit-not too much, justby 1 or 2 dB. Then add a little bit of 60 Hz, but again, just by about2 or 3 dB."
A lot of alternative records have a hollower, more gritty-soundingkick drum. You can dial in this sound by rolling off everything below100 Hz-yes, you heard me right. Boost 125 Hz by about 3 dB, and addabout 4 dB between 250 and 350 Hz. Then roll off everything above 2kHz.
2. SNARE DRUM Two of the most widely used snare-drum sounds inpopular music are a tight, punchy snare and a loose, full-soundingsnare (usually used on ballads). Naturally, the way the drum is tunedwill influence how you decide to EQ it.
A snare never needs frequencies below 150 Hz, so roll them off. Thecenter frequency of a snare is usually around 1 kHz, give or take a fewhundred hertz, so it usually benefits any snare to boost around thatpoint by approximately 3 to 6 dB.
For a tight-sounding drum, Martin explains, "you'll want to workwith the upper mids, around 5 kHz, and some higher frequencies, like at8 or 9 kHz. Try boosting in each area, starting with 3 dB and workingyour way up. Also, you'll need to sweep the frequency parameters untilyou nail it. Attenuating low frequencies is a good idea, so get rid ofanything below 250 Hz, and if you still have an EQ band left, roll offeverything above 11 kHz. A tight gate usually sounds good on this typeof snare."
"A ballad snare," Petricelli notes, "needs a bit more bottom end, sotry boosting around 250 Hz to give it a fuller tone. I'd start with anincrease of 6 dB. You won't need to boost as much high end as you wouldwith a tight snare-though adding a little around 7 kHz might behelpful, and you can roll off everything above that. The key elementhere is your center frequency: you don't want too much ring to thedrum, but you want it to have some ring. Find the resonant frequency ofthe snare by turning the gain all the way up and sweeping between 800Hz and 2 kHz. When you find it, narrow in on it with the Q control. Nowyou can adjust the gain accordingly. A loose gate and heavy reverbcomplement this type of snare sound."
3. DRUM KIT Drum overheads can be a bit tricky, and how you EQ themdepends on how the entire drum kit was miked. "If you have individualmics on the tom-toms, snare, and kick drum," says Martin, "you onlyneed the overheads to capture the cymbals and to blend the kit. In thiscase, you could probably just use a low shelving filter to reduce theamplitude of everything below 4 kHz. This way, you have individualcontrol over the snare, toms, and kick, and the overheads take care ofthe rest. Depending on what mics were used, you might have to boostsome high frequencies to get a decent cymbal blend-probably between 10and 14 Hz by about 3 dB."
These days, though, a lot of engineers record drum tracks with onlyfour mics: a kick, a snare, and two overheads. This gives the drums amore natural, almost raw sound, but it makes equalizing them much moredifficult. In this case, you need to keep the overheads' low end inplace to sufficiently capture the toms, but not so much as to addboominess to the kick or snare drums.
Let's look at an example from a project I recently completed. Thedrum overheads were recorded pretty flat-not bad, but not all thatexciting. After playing around with the console EQ, it became clearthat we needed some outside assistance, so I patched in a CLM DynamicsExpounder. To liven up these two tracks, I started by adding about 10dB at 150 Hz to bring out the toms, which were overshadowed by thecymbals. I then notched out an offending ring at 250 Hz produced by themiddle tom. In addition, because the snare had a prominent ring at 1kHz and we already had a dedicated snare track, I pulled out 1 kHz byabout 6 dB with a 1.0 bandwidth setting, which also helped to round outthe toms. Finally, although we had plenty of cymbals in our mix, Iadded about 3 dB at 9.5 kHz, just to smooth things over.
A similar example can be seen in Figure 4. Here everything above 1.5kHz sounded great, but again the toms were being washed out. In thisinstance, I used the console EQ, boosting the low shelf by 8 dB at 191Hz to add some low end. This also augmented the kick drum. I boosted 3dB at 152 Hz, and I notched out a tom ring at 666 Hz and a snare ringat 1,017 Hz.
4. HAND PERCUSSION Percussion comes in many forms, but here we'llfocus on the more common instruments, such as shakers, tambourines,congas, and hand claps.
Shakers and tambourines fall into roughly the same category withregard to EQ: both need to be bright and should cut through the mix onthe high-end side. Martin discusses his philosophy on hand percussion:"For shakers, I usually just roll off everything below 2 kHz and add abit of high end, like 6 dB at 9 kHz. That usually works fine.Tambourine requires a bit more 'clanginess,' so for it I roll off below800 Hz, boost 1.5 or 2 kHz by about 4 dB, and add a little around 7kHz."
Petricelli often records congas for his commercial work. "Ifrecorded properly," he notes, "congas don't really need that muchtweaking with EQ. I usually find the resonant frequency of the drum bydoing an EQ sweep, and either add or subtract a little depending on thesituation. A boost generally helps to bring out the natural timbre ofthe drum. But you need to be careful not to add too much, especially ifthe resonant frequency is low, as it will clash with the other drumsand the bass. To bring out the attack of the drum, I usually boost abit in the midrange-say, around 5 kHz, maybe by 6 dB. You can roll offeverything above and below the range of the drum."
Finally, hand claps are generally fattened up by adding some lowmids, usually around 250 Hz by about 2 dB, with a 1.5 Q factor. Also,to get more of an attack, boost some of the midrange (around 1.5 kHz byabout 4 dB) and add some highs (around 8 kHz by 2 or 3 dB shouldsuffice).
5. ACOUSTIC PIANO Piano EQ can be approached in two ways, dependingon how much accompaniment the piano will have. Will it be the maininstrument in the mix, perhaps with a vocal and bass? Or will it be inthe back of a full-band mix with seven or eight other instruments?
Martin explains, "If you have a solo piano, with little or noaccompaniment, and it's been recorded properly, you really shouldn'thave to do much to it. Often, I like to boost a little low end, around140 Hz, but only if there's no other bass instrument in the mix. Also,try adding a bit of high end, around 8.5 kHz-but not too much, justabout 3 dB.
"If, however, you have to fit the instrument into a tightly packedmix," he continues, "you'll need to do some subtractive EQ. A pianonaturally has a 'honky' sound because much of the playing is done inthe middle of the keyboard. This is what you want to watch out for.Yes, you want the midrange to be out in the mix, but you don't want itto sound obnoxious, so you may have to do some attenuating around 3 or4 kHz. Also try rolling off the frequencies below 140 Hz, because theywill definitely clash with your bass guitar and kick drum. A slightboost around 8 kHz can bring out the upper keys. All in all, how muchyou boost or how much you cut will depend on the nature of the mix andits components. Try to coax the midrange and upper mids from the piano,but walk a fine line so that it doesn't sound honky."
6. BASS GUITAR With electric bass guitar, you have a lot of options,especially if the track was recorded with a direct injection (DI) box.One of my favorite bass sounds is illustrated in Figure 5. This trackwas recorded with a DI box, and we wanted a sound that brought out eachnote being played, without "slappiness." We started by rolling offeverything above 520 Hz and below 100 Hz. We used a boost of 6 dB at260 Hz to fatten up the tone, and a boost of 3 dB at 730 Hz to add somefinger noise. This EQ, along with some moderate compression andlimiting, produces a rich, fat, full tone that works well with any typeof music.
For a player who slaps and punches and needs a funkier sound, youcould use the same EQ settings, but instead of rolling everything offat 520 Hz, boost some mids around 2 kHz by about 4 to 6 dB. Thisprovides the slap. You might want to decrease the low-end rolloff toabout 50 Hz to give the track more rumble.
Often a graphic EQ can be used to zero in on a bass sound. "Iusually use a graphic EQ on bass tracks," says Petricelli. "If thetrack has been done direct, this is almost a must, because you don'thave the liberty of equalizing the player's amp, moving the mic, and soon. I use a 20-band EQ that can dial in just about any bass sound Iwant. The nice thing is that with a graphic EQ, you can see the curveyou're drawing by looking at the unit. The tips for getting a sound arethe same as with a parametric EQ; you just have more frequencyoptions."
7. ELECTRIC GUITAR As with the piano, how you treat the electricguitar depends on the other elements of the mix. For example, if youhave only one electric guitar in a mix with just drums and bass, youcan make the track sound large. However, if you have three otherelectric guitars, a piano, keyboards, percussion-the works-then youhave to fit it nicely into a spot on the soundstage. Let's look at acouple of such scenarios.
Let's say that you can do whatever you want to this guitar to makeit sound as big as possible, as long as it doesn't conflict with thebass guitar. Martin notes that "if I'm working with a simple rock bandthat has only one guitar player-you know, The Who Live at Leeds-I'lltry to fatten up the low end as much as possible. Usually, a boost of 3dB around 160 Hz is a good start, as long as it sits well with yourbass. Also, try adding a little around 700 or 800 Hz. Depending on thesound of the amp, you might need to pull out some midrange; if you do,it will generally be around 3 kHz. How much high end you add depends onthe sound you're going for: a boost of about 6 dB at 7 kHz will giveyou a crunchier sound." Again, it's always good practice to roll offanything above or below the frequencies that are not needed; but listencarefully before you cut, lest you accidentally eliminate desirable,but subtle, low-level subharmonics and high harmonics.
For our second scenario, let's assume you have to fit this guitarinto a mix with a full band, including two other electric guitars. Myadvice is to focus on the midrange. Roll off everything below 200 Hzand above 9 kHz. Then do some sweeps in the middle to see what needs togo in and what needs to come out. I find that a boost around 4 kHz anda cut around 6 kHz generally works, although sometimes the opposite istrue. You have to listen to the track and decide according to the mixat hand. If you have more than one electric guitar, make sure that theysound a little different from each other. This could mean usingdifferent guitars, amps, mics, miking techniques, or processing.There's nothing more grating than three guitars playing the same thing,all with the same sound.
8. ACOUSTIC GUITAR To illustrate how dramatically the EQ of anacoustic guitar can change from one mix to another, let's look atFigures 6 and 7. Both EQs were applied to the same track, but indifferent mixes.
Figure 6 shows an acoustic guitar track that has been worked into amix with drums, bass, piano, electric guitars, percussion, and lots ofvocals. This track was recorded with a very nice Martin acoustic guitarmiked with an Audio-Technica AT 4033. Here, I rolled off everythingbelow 90 Hz and added a bit of body around 360 Hz. I really boosted themiddle and upper frequencies, though: 10 dB at 2 kHz and 9 dB at 7.1kHz. With everything else happening in this mix, the acoustic guitarhad to sound bright-and it did.
Now look at Figure 7, which shows the same guitar track, only withinan alternate mix of acoustic guitar, vocals, and percussion. This time,I decreased the low-end rolloff to 43 Hz to give the guitar a fullersound, and I made a 3.4 dB boost at 166 Hz to achieve the same goal.The midrange boost has been moved to 3.1 kHz and is at only 7 dB, andinstead of increasing 7.1 kHz with a 9 dB bell curve, I've used asmoother shelf to gradually raise the high end.
Martin notes that strings or string patches follow a similarapproach. "A string section has many of the same tonal characteristicsas an acoustic guitar," he explains. "I usually roll off most of thelow-end content, assuming that the strings will be placed in a fullmix. I then boost the upper mids a bit around 4 dB at 7 kHz, and maybegive the sample some 'airiness' by boosting with a shelving EQ around10 kHz."
9. BRASS AND WINDS Some horns are naturally strong in the midrange,so bringing out those particular frequencies is important. Forinstruments such as the trumpet, roll off the low end completely,around 200 Hz or even higher. Depending on the recording or sample, youmight have to tame some midrange to avoid a honky sound.
Conversely, with brass instruments that rely on the low end, youmight want to roll off the upper frequencies-say, above 9 kHz. Usuallya boost in the low mids helps bring out these instruments in a mix,probably around 1.5 kHz. When working with tuba or with tuba samples,be sure to use a filter to roll off frequencies below 40 Hz; this wayyou ensure that no speakers get blown, especially during low notes.
Most wind instruments need to be airy, which commonly involvesfrequencies above 9 kHz. Usually a shelving EQ works well to augmentthis characteristic. A bassoon can produce extremely low notes, sodon't filter out its low frequencies; but for many wind instruments youshould use a low-frequency filter.
10. LEAD VOCALS A vocal track must have body, presence, and air, butnot so much as to interfere with the rest of the mix. Vocals also needto be out front in the mix, and this is usually accomplished byboosting the midrange. Petricelli elaborates: "Vocals are what sell theproduct, whether it's a song or a sung commercial, so they need to beaudible but not annoying. It's a fine line to walk." Understand thatvocal tracks are the most sensitive you will have to EQ, and because somany variables are involved, making categorical statements about vocalEQ is difficult. You'll have to listen and decide for yourself.
It's important to note, however, that there is a big differencebetween recording male and female voices. "I just finished a session inwhich we had two singers, a man and a woman, who were doing a duet,"Martin explains. "They were recorded in the same room, with the samemic, roughly ten minutes apart. When we went to mix, the tonaldifferences were amazing."
Based on what Martin told me, I re-created the two EQ settings shownin Figure 8. The tracks were recorded with a Neumann U67 mic and runthrough a UREI LA-2A limiter. This illustration should give you an ideaof how vocals are typically equalized. The male singer's track appearson the left EQ, and the female's track is on the right.
Immediately, you'll notice that the male vocal gets anupper-frequency boost of 1 dB with a shelving EQ, while the femalevocal requires a 3 dB shelving cut at 8.8 kHz. The male vocal alsoneeds a 2 dB boost at 7.5 kHz and a 5 dB cut at 5.1 kHz. Martin told methat this was because the singer had a cold and sounded a bit nasal.Conversely, the female singer's track was treated with two 4 dB low-endboosts-one at 733 Hz and another at 283 Hz-to make its low-end contentcomplement that of the male singer's track. Interestingly, both vocaltracks got a similar boost around 2.5 kHz, illustrating how importantit is to bring out the midrange in a vocal track.
11. BACKGROUND VOCALS "There are two kinds of background vocals,"Martin points out. "The first is your standard harmony that sits anoctave above the lead and comes in on the chorus. This is almost likeanother lead vocal, and I generally EQ it using the same approach. Theother type of background vocal is the choral effect, in which you mayhave three or four backgrounds, at all varying octaves, panned acrossthe soundstage. For this I use a different approach: these vocalstypically sound better when they have a bit of 'air' to them and soundalmost unearthly.
"To get this effect, I usually roll off low frequencies on highharmonies, usually around 400 Hz, and attenuate extremely lowfrequencies on low harmonies, around 100 Hz. Then I take out as muchmidrange as I can without losing the clarity of the voice-try filteringout anywhere between 1 and 4 kHz. Finally, I add a lot of upper midsand high frequencies. I usually put a shelving EQ on around 8 or 9 kHz,sometimes higher, and boost it until I have that angelic effect."
12. NARRATION Obviously, if you're working with a narrative thatdoesn't need to blend into a music mix, you can fatten up the sound ofthe announcer's voice. Petricelli commonly does this.
"In this case," he explains, "you can leave a lot more low end inthe voice than you could if you were doing a music mix. Announcers aresupposed to have big, godlike voices, so you need to make them soundthat way. Start by boosting a bit between 60 and 120 Hz, depending onthe tonality of the voice you're working with. Then go all the way uptop and add some high end, probably around 7 kHz. You might need topull the mids back a little, but make sure you don't lose any clarity.It's somewhat similar to the way you'd set your home stereo."
13. REMOVING ARTIFACTS As mentioned earlier, filters and EQs aregreat tools for removing sonic garbage. The most obvious example ofthis is using a filter to notch out a 60 Hz AC hum. However, you canuse a notch filter to get rid of almost anything, and you can use aparametric EQ to create a notch filter. Martin relates a story.
"We were doing a session in which we had a percussionist playing thecongas" he says. "When we listened to the playback-months after he hadoriginally cut the track-we noticed an odd clicking sound that came upevery so often. We couldn't figure out what it was. It turned out thatthe guy was wearing a ring on his right index finger that occasionallyhit the lug on the side of the drum. We couldn't redo the track, so Ithought I'd try to EQ it out with a parametric. By turning the gain allthe way down and gradually sweeping the frequency knob and zeroing inwith the Q control, I was able to isolate not one, but three differentfrequencies that were causing this click. We eliminated the noisewithout affecting the sonic characteristic of the drum."
14. ONE EQ FOR TWO Often, especially in the world of digital audioworkstations, sound designers wind up with more than one instrument ona particular track. If your automation package allows you to automateEQ changes dynamically, there's no problem: you simply switch from oneEQ setting to another at the appropriate time in the mix. If yoursoftware doesn't offer this feature, however, you'll have to getcreative, or at least reach a compromise.
Let's look at another example from a project I recently did (seeFig. 9). One track contains a lead guitar, background vocal, and handclaps. The vocal and the hand claps were recorded using the same mic(an AT 4033) and had a similar sonic content-but, as you can imagine,the guitar sounded quite different. So we needed to make somecompromises. The first thing I realized was that none of theinstruments needed anything above 15 kHz, so I gradually rolled it offat 11 kHz. I then boosted the midrange a little at 4 kHz to bring outthe vocal; that, unfortunately, also made the guitar sound clangy. Soto compensate, I added some low end for the guitar, around 300 Hz,which didn't really affect the vocal in a bad way. I then boosted about2 dB at 8 kHz for some clarity to the guitar and vocal. Lo and behold,with all these changes, the hand claps sounded fine!
The moral of the story is that if you have to comp tracks together,make sure the instruments on them have similar frequency responses.
TWEAK IT, BABY! An EQ can either ruin a recording or make it shine;it's a very powerful tool. That power is harnessed by the ear,experience, and knowledge of the person operating it. The first twothings can't be taught in an article or a classroom, but the tipsoffered here should be helpful to anyone, whether you're a novice or apro. These solid approaches to EQ have been used for many years byseasoned engineers. But that's not to say they're set in stone; likeanything else in this business, creativity is the key.
EM associate editor Jeff Casey has a 10-band fully parametric EQ onhis car stereo.