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In The Studio: Using Multiband EQ To “Fix It In The Mix”

Try these suggestions, but then try something totally different. Innovate – don't blindly follow...
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Before there was digital recording, before spring reverb, even before analog tape, there was EQ. Equalization is one of the oldest tools in the audio engineer’s arsenal, and one of the most useful.

Used judiciously, EQ can do wonders to de-clutter a crowded soundscape. Used with precision, it can remove offending sounds we hadn’t necessarily intended to capture. Used correctly, a bit of EQ can be all that’s needed to make peace between dueling guitars, scoop the mud from the heaviest drums, or make a mundane vocal stand up and shine.

But all too often, EQ is misused and misunderstood, typically in a vain attempt to fix a poor recording.

Rule Number One in recording still applies: garbage in equals garbage out. A little EQ is great for helping make a good track sound better, but no amount of EQ will make a bad track sound good.

The best mix starts with the best recording, so try to capture the best sound you can to begin with. Move mics, listen at the source, not just in the control room or in your headphones. Make sure what’s being recorded sounds as close to what’s being played as possible – before it’s too late to do anything about it.

Your ears are the bottom line when it comes to applying EQ. While we can talk about a few general principles, every instrument has its own unique characteristics and timbre, and will react differently to boosting or cutting specific frequencies. So take these and all suggestions with a few grains of salt; use them as a starting point but make your decisions based on what sounds good.

EQ Giveth & EQ Taketh Away

When it comes to EQing, less truly is more, and in nearly all cases it’s better to take away than to add. Many less experienced users have a tendency to make an instrument stand out by boosting frequencies, but the cumulative results can be dangerous.

Adding just 2 dB of gain to two different instruments means that when they excite the same frequencies (and trust me, they will, and probably at the worst possible moment), you’ve got 4 dB of gain. Add too much EQ and your mix can easily turn to mud. It’s often a better idea to try attenuating those same frequencies in other instruments instead.

Another good reason to minimize your use of additive EQ: while cutting frequencies is a passive process, boosting frequencies makes your EQ function as a preamp within the signal flow. Adding any preamp means adding noise and distortion, and the preamps in most EQ circuitry are less than optimal.

All those arguments aside, sometimes it’s simply more effective to boost one element of the mix, rather than rolling off dozens of others. Once again, the operative word here is moderation – a little boost of 1 or 2 dB goes a long way.

Drums – If It Doesn’t Fit, You Must EQ It

If your mix includes drums, it’s a good bet you’ll spend a considerable portion of your mixdown time EQing them. Because drums cover such a wide tonal range, there’s plenty of other stuff in the mix that can compete with those frequencies. Kick and snare in particular tend to be prominent parts of the song’s sonic fabric, and when it comes to helping them play nicely with other instruments and vocals, EQ is your best friend.

Of course, assuming you’re working with a live drum kit (as opposed to isolated drum samples), you’re not working in a vacuum. Since every drum track also contains leakage from other mic, boosting a frequency on one track can also bring up the off-axis sounds of adjacent mics, potentially creating more problems than it solves.

For a dull sounding kick drum, adding a slight boost anywhere around 80 Hz to 120 Hz will produce more boom and a more rounded “thud.” (Typically, the kick tends to compete with the bass guitar for that frequency range, and it’s a good idea to decide which of the two should occupy the lower and upper edges of that zone. See the section on bass later in this article for more on this.)

Adding a tiny bit of 500 Hz can bring out the “click” of the beater hitting the drum head, and can be helpful in preventing the kick from disappearing once your track hits the listener’s earbuds in the inevitable low-fi MP3 version.

Snares come in such a wide range of sizes and materials, it’s a bit tough to generalize about frequencies. But the sound of the snare wires rattling lives in the 5 kHz to 10 kHz range, and a bit of gain there is great for brightening up a dull snare. If you’re plagued with a boxy sounding snare, try rolling off a bit of 300 through 800 Hz.

With toms, a common mistake is to try boosting low end to make them stand out. Adding a couple of dB at 100 Hz will increase their power, but at the expense of muddying the mix. A better strategy for perking up those tom fills is to leave the bottom end alone and add a tiny bit of 5 kHz to bring out the attack. And as with the snare, play around with rolling off that same 300 through 800 Hz range to eliminate boxiness.

Almost every tom has a resonant ring, and some can be problematic. Of course, the basics apply: tune the toms first and foremost to reduce or eliminate ringing. Whatever problem resonance remains can be addressed using a surgical approach with a multiband EQ. Select a narrow Q and boost the gain as you sweep the midrange band. When you locate the offending frequency, apply a few dB worth of cut to make it go away.

Overhead mics can be a mixed blessing. Their position and relative distance from the kit makes them great for adding air and ambience, but loud cymbals can overpower the mix. Try adding a bit of 10 kHz to brighten the track, and then backing off the overall level to get the air without too much metal.

The Bottom Line On Bass

Since bass and kick occupy the same frequency range and (hopefully) work together, it’s almost always necessary to use EQ to differentiate them in the mix. As mentioned earlier, it’s best to pick one as the rounder, bottom-y sound and make the other a bit more bright and punchy; which is which will be dictated by the song.

One of the questions i hear most often is whether it’s best to record the bass direct or mic the amp. The answer, as you might expect, is “it depends.” Ideally, many engineers opt to record both the amp and a direct track simultaneously, balancing them in the mix for the best possible tone.

Of course, in today’s project studio world, it’s not always possible to record live at the volume you’d like. If you’re working with a bass track that was recorded direct, chances are it’s a bit flat and nondescript compared with a mic’ed bass amp. The good news is, that flatness will ultimately make EQing the DI track far easier, since there’s less coloration to begin with.

Like the kick drum, boosting the 80-120 Hz range on an electric bass will add roundness and bottom end. To add presence and attack, go for a slightly higher range than with the kick, around 1 kHz. Don’t add too much or you’ll bring out the finger noise as well.

Making Space For Guitars & Keys

Guitars are among the most versatile instruments; that same versatility can make them a real challenge. With electric guitars, if you’re fortunate to have a player who knows their amp and their sound, your best bet is to change as little as possible.

If you’ve got two rhythm guitar parts going, a bit of panning and EQ can help distinguish one from the other. Try a slight boost at around 100 Hz on one to bring up the lower mids (with perhaps a corresponding cut on the other guitar). Experiment with higher frequencies on the second part – boosting different frequencies between about 750 Hz and 10 kHz will each bring out a different type of sparkle. Scooping out a bit of 250 to 500 Hz can help eliminate some harshness and woofiness.

Acoustic guitar is a very different animal. Each has its own unique tone and timbre, and much will depend on the player, the sound of the room, the mics you’ve used and where you’ve placed them. A mic too close to the sound hole will deliver a boomy sound; a slight cut at 100 Hz can help. Close miking can also pick up some boxiness from the wood’s resonance, especially around the midrange. Try dropping a bit of the 300 to 400 Hz range. And of course, bring out the shimmer and strumming sound by boosting the upper ranges, from 750 Hz up to around 10 kHz (watching out again for finger noise).

Acoustic pianos, like their guitar counterparts, are organic instruments subject to a number of unique conditions. Every piano has its own character and tone to begin with, further affected by the room, the mics, mic placement and of course, the player. Few instruments cover as wide a range of frequencies and overtones as the piano, which can be both a blessing and a curse. What you do with regard to EQ depends largely on the song – a dense part with close-clustered chords is probably best treated with subtractive EQ, while a spare, melodic passage might benefit from a bit of boost in the upper mids.

Keyboards are a whole other issue, and could easily be the subject of an entire article alone. Synths cover such a wide range of sounds, it’s impossible to generalize about what will work on any given patch. For the most part, you’re quite literally playing it by ear.

Listen Before You Look

I’ll close with the same point I opened with: take this and all advice as nothing more than suggestions. There are no hard and fast rules except one: use your ears. If it sounds wrong, it probably is. So close your eyes and listen. Adjust your EQ, close your eyes and listen again. Don’t just solo the track, either – listen to your changes in the context of the whole mix.

Especially in today’s DAW-oriented world, we all have a tendency to stare at the screen. But it’s important not to depend on spectrum analyzers and meters instead of listening. Try out these suggestions, but then try something totally different. Innovate – don’t blindly follow. Every song is unique, every instrument and room is different, and every artist and song is distinctive.

What worked for one person on one recording won’t necessarily be what’s right for you.

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