From DRUM! Magazine’s January 2018 Issue | By Mike Levine
In many aspects of life, moderation is the key to success. A drop of hot sauce can make your food spicy and interesting, but if you dump the whole bottle in, the results will be unpleasant. A few beers over the course of an evening can be quite enjoyable, but if you drink a case, you’ll probably regret it.
The same concept is true when it comes to mixing. The methods that you use to make a mix sound great can be ruinous if you overdo them. In this article we’ll look at some key mixing tools and techniques, and talk about how to — and how not to — apply them.
All Things Being Equalized
Your equalizer is perhaps the most critical processor in your mix arsenal, because it allows you to sculpt the frequency content of each track. Every element in your mix will likely need some form of equalization to make it sound better. But whatever you’re trying to do with your EQ, it’s best to use it judiciously, or you can easily create more problems than you solve.
It’s tempting to solo each track and try to make it sound as good as possible with your EQ, but don’t lose sight of the bigger picture. As you make your adjustments, be sure to also listen with the rest of the tracks turned on to assure that the equalization you’re applying is helping in the context of the overall mix.
Cutting is typically safer than boosting, because the latter will make your track take up more, not less, frequency space, and will be more likely to mask another track in the same frequency range.
Boosting in the 2kHz to 5kHz area can make a dull-sounding track sound brighter and more distinct, but overdo it and you can create harshness instead. If too many tracks in your mix are boosted in that area, the whole mix may begin to sound harsh. Whether boosting or cutting, try to keep the level of your boosts low and set the Q parameter (aka “bandwidth”) to be relatively narrow (Fig. 1).
Many engineers do a lot of high-pass (aka “low cut”) filtering during a mix. The idea is to cut out unneeded frequencies at the low end of an instrument or vocal track, to help avoid muddiness in the lower midrange and bass frequencies of your mix. Basically, there’s a lot of information at the bottom end of tracks that, when combined with a lot of other tracks that also have it, will create a sea of mud. By cutting out those unneeded frequencies, you can clean up the bottom end of your mix.
Here’s a good approach that keeps you from overdoing it. Turn on the high-pass filter in your EQ plug-in, and start turning the frequency knob higher until you hear the instrument or voice audibly thin out. Then back it off until just before that point. Any track that lives mostly in the mid- to high-frequency ranges often sounds fine with its lower frequencies filtered. You can even safely high-pass a kick drum or bass without causing it to lose its oomph, as long as you set the cutoff frequency at about 40Hz or lower.
On the other end of the frequency spectrum, low pass (aka “high cut”) filters are also used to clean up unneeded high-end frequencies. Again, care must be taken not to overdo it, or you’ll end up with a dull-sounding mix.
Don’t Get Too Wet
In a mix, the function of ambient effects like reverb and delay is to add space. This is often necessary because in the studio, microphones are usually placed close to the source in order to capture maximum fidelity. This is especially true in home studios, which tend to have poor acoustics compared to professional facilities. As a result of this mike placement, most instrument and vocal tracks don’t have a lot of room reflections in them, and can sound stark and lifeless. Reverb and delay can be useful for making instruments sound more natural. But be aware that the more “wet” a track is, the more it will seem to recede toward the back of the mix. Reverb is particularly helpful not only for adding space, but for helping a track blend in better with the rest of the mix. Even if, say, your vocals and acoustic guitars were recorded with different mikes in different rooms, using the same reverb on both will help glue them together sonically.
But beware — reverb is really easy to overuse. Almost nothing says “amateur mix” more than a song dripping in reverb. Be careful how you set your decay time (aka “reverb time” or “room size”). If your reverb has a really long decay time, it will wash over the subsequent notes or drum hits, and could turn your mix into a muddy, indistinct mess. You can get away with a longer decay time on a vocal or melodic/harmonic instrument than you can on a percussive element such as a drum. Because a drum hit is so short, you generally want to keep your decay times short to compensate; usually about 1.0 second or less (Fig. 2) works.
If you choose a reverb with a long decay, it’s particularly important to use subtlety when adding it to a track, and especially to multiple tracks. Otherwise the decaying reverb tails can wash over your mix and muddy it up. If you apply the reverb via an aux send, keep the individual channel send at a nice low level. If you insert a reverb directly onto a track, keep the wet/dry mix parameter closer to dry, so the reverb doesn’t overwhelm the sound. The operating principle when dialing in reverb should be “less is more.”
The amount of reverb that’s considered normal is also a function of the musical style. If you’re familiar with the genre you’re mixing in, you’ll have a sense for what works and what doesn’t. If you’re not sure, do some listening research. The same reverb setting that sounds good in a pop song might seem out of place in an indie-rock track.
Compressors have a dual role in mixing. They’re used for keeping dynamics under control automatically — either on individual tracks or the full mix — and for coloring the sound of instruments and vocals.
Let’s start with the first application. A compressor can function as an automatic gain control of sorts. You set a threshold, and anytime the signal exceeds it, it will be attenuated by a specified amount. Another key parameter is the compression ratio. The higher you set it, the more attenuation is applied to any signal that exceeds the threshold.
Most compressors have attack and release controls, which determine how quickly the compression kicks in and holds, respectively. Fast attack times squash the transients in a signal, making the track sound less snappy and also more obviously compressed. Sometimes you want that, but if you’re, say, compressing a snare drum, a fast attack time will diminish the initial transient when the stick hits the head, taking away some of its power.
It’s not just drums. Any track with fast transients, such as a tambourine or even an acoustic guitar, usually sounds better with an attack setting longer than about 12ms. This allows the initial transients to get through before the compressor clamps down.
The release control also affects how aggressive the compressor sounds. Slow settings generally sound more natural than fast ones. It’s useful to experiment with the release settings to get the impact you want.
So why do you need a compressor for dynamics control? Let’s say you have a vocal track that has some pretty loud peaks, where the singer was really belting. If you don’t compress it (or use automation to reduce peaks, or both), the vocal is likely to jump out at the listener when those louder notes occur. In a worst-case scenario, the listener will feel the need to turn down the volume. You don’t want that to happen. You want the dynamics to be smooth enough that there are no elements with such high peaks. Consider this: if you lower the level of the peaks, you’re reducing the dynamic range of the track, which means you can turn the whole track up, and bring out the quieter parts, without loud peaks.
A compressor with a ratio that’s 10:1 or above is considered to be a limiter. If its ratio is Infinity:1, it’s called a “brickwall limiter,” because it keeps any of the signal from exceeding the threshold. Probably the most common use of a brickwall limiter is on the master channel (aka “master bus”) to make the entire mix louder. It does so by squashing down the peaks and reducing the dynamic range (the difference between the loudest and softest notes), thus making it possible to boost the entire track to a higher level.
If your project is going to a mastering engineer, it’s better to not use a brickwall limiter on the master bus. That way the mastering engineer will have enough headroom to do his or her more expert limiting. If you shrink the dynamic range too much, it can sound unnatural and even fatiguing to the listener. This is true whether you’re limiting an entire mix or compressing individual tracks. You want to control the dynamics in your music, but not eliminate them.
Some compressors are considered “transparent.” That means they add very little color to the tone, and are good for situations where you want dynamics control but don’t want the track to sound obviously compressed. Others are used specifically to add coloration. The famous Urei 1176, of which there are many digital plug-in emulations (Fig. 3), is an example of a “color compressor,” as it adds a distinctive sound to the sources it compresses.
Certain mix elements often sound better with a compressor altering their tone. Kicks and especially snares sound particularly good compressed. But be careful when compressing a track with cymbals, such as a drum overhead. A compressor can alter the decay of cymbals, especially crashes, in a way that sounds quite unnatural.
Parallel compression is a popular technique. It’s often used on drums, and is a good way to get a compressed sound without overly squashing the transients of the source. It entails bringing up a copy of a track in addition to the original. The copy is compressed heavily, and the other not at all. You then bring up just enough of the heavily compressed track to achieve the desired sound. At the highest peaks, the noncompressed signal is louder, thus allowing the transients to get through. If you have a compressor plug-in with a mix control, you can back it off from 100-percent compressed to achieve the same effect on a single track.
A Left & A Right
Panning instruments and voices in the stereo spectrum is one of the easiest ways to give each mix element its own space. After a brief period in the early days of stereo, where you’d hear songs with the drum kit panned all the way to one side, or the instruments on one side and the vocals on the other, certain standards have evolved that almost everyone adheres to. Most importantly, these include keeping the bass guitar, kick, snare, and lead vocals at or near the center.
Beyond that, however, panning strategies differ from engineer to engineer. Some like to place elements all over the soundstage, because it helps them find a unique place for everything. Others adhere to the “LCR” (Left-Center-Right) approach, in which everything in the mix is either all the way left, in the center or all the way right (Fig. 4). This method tends to give you a wider, more airy-sounding mix, and accentuates the vocals and other center elements. However, it requires you to stack a lot of elements on the left or right, so you have to do more with EQ and ambience to give them their own space.
Can you overdo it with panning? Yes, in a couple of ways. One is to pan with no rhyme or reason to the placement. It’s important to strive for coherence and consistency in the soundscape you create. The placement of the mix elements should make some sense to the listener. For example, decide from which perspective you want to mix the drums — from that of the drummer or the audience. Then make sure the panning of all your drum tracks stays consistent with that, and therefore all the tracks are consistent with each other.
The other big no-no is to overuse autopanning. An autopan effect can add some nice motion to a mix by subtly moving an element around the stereo spectrum. However, there’s a fine line between a cool autopanning effect and a cheesy, overdone one. Usually, the best results come from subtle settings that blend naturally with the mix. If the listener can tell that an element is being autopanned, you should probably reduce the speed of the panning.
Back It Off
As a mixer, you have control over levels, panning, EQ, compression, and all the other aspects of processing. As a result, your decisions impact the ultimate sound of the song in profound ways. But never forget that the primary goal of a mixer is not to draw attention to him or herself, but rather to present the song and the performances in the most flattering way possible. As with an umpire in baseball, the less you’re noticed, the better job you’re doing. To that end, subtlety and judiciousness should be your watchwords when you mix.