There are as many approaches to mixing live music are there are people who sit behind mixers. Some engineers are highly analytical, perhaps with a functional understanding of frequencies, decibels and other technical concepts. Others are more “intuitive” in their approach, working the knobs and faders to achieve the sound they hear in their heads. Some start their mix by compressing vocalists to perfection, others get kick drum and bass equalized for maximum impact before another fader is lifted.
Regardless of approach, every sound engineer should be working toward the same goals—a cohesive, spacious mix in which instruments complement each other instead of compete. A mix in which critical instruments and voices are supported and enveloped without being overwhelmed. A mix that fills the venue with appropriate energy while not being overly loud. A mix that is much more than the sum of its parts.
This article will present several tried-and-true approaches to achieving these goals, as well as offer up some different ways to conceptualize an effective mix. Keep in mind there’s no right or wrong way to mix live sound—only you can decide what approach matches your technical knowledge, abilities and personality.
All About Control Before we begin, it’s worth taking a look at the tools a sound engineer has at his or her disposal in their quest to build the “perfect” mix. Understanding how these tools work—and how they affect the sound—is the most important knowledge a sound engineer can have. Arguably the most powerful tool in the toolbox is the fader itself. Being able to adjust the overall level of a sound is where a great mix begins—the rest just enhances what the fader achieves. The mute button (the ultimate fader) can also be a very effective mixing tool.
Next up is equalization, where the tonal character of the sound can be adjusted independent of its overall volume. Nearly as important as overall level, EQ lets you change a sound’s frequency balance to better complement the mix—not necessarily the instrument itself. Related to equalization is using mic placement and distance to control an instrument’s tonal character.
The last of the “power tools” is panning (or stereo positioning). Stereo and left-center-right sound systems allow sounds to be separated spatially, which can add much perceived space and distinction between instruments. Stereo placement lets you literally “wrap” the main vocal in sound without those instruments or voices compromising its intelligibility. Other tools allow for enhancement of a mix, but aren’t as crucial in most church sound situations. These include compression, limiting, time-based effects such as delay and reverb, and pitch-based effects like chorus and flange. Added with care, these elements can take a well-balanced mix to the next level. Used without discretion, they can ransack the clarity and detail of your mix.
Bottom Up, Top Down
After monitors are dialed and musicians have a stage mix that’s agreeable
to them, it’s time to start rolling instruments and voices into the house
sound system. One effective approach is to begin by bringing up the foundational
rhythm instruments, such as drum kit, bass guitar, electric guitar or piano.
The term “foundational” isn’t used here by accident—you
should think of these instruments as the supporting structure on which a solid
mix is built. Leave your mix lacking in these instruments, and it may sound
top-heavy and weak.
This
“bottom up” approach usually involves working your way up through
instruments and voices, with “up” referring both to frequency and
prominence in the mix. A large band/orchestra mix might start with the rhythm
instruments already mentioned, moving then to acoustic guitar, organ, synth/keyboard/
electric piano, low strings (double bass) through violin, low brass (trombone)
through trumpet, percussion, choir, vocal ensemble and finally worship leader.
See figure 1.
With each new element added, the goal is to set levels, equalization and panning so that the instruments function in their own acoustic space without competing with one another. The real challenge with bottom-up mixing is to leave room at the top for the most-important element(s) without getting the mix too loud. All too often, the final vocalist pushes the mix over the edge in volume, requiring everything else to be brought down to compensate. In some cases, the mix practically needs to be rebuilt from scratch.
The top-down approach avoids this problem by starting with the most important element (usually the vocal leader and his or her instrument, if any), then adding in the other instruments and vocalists beneath. This means going down through the mix elements in order of prominence and/or frequency range, filling out the sound with those “foundational” rhythm instruments as a final step. Overall volume usually stays under control with this method, but it’s easy to lose some of the less-prominent instruments as you descend into the mix.
Sound Slots
In addition to visualizing a mix as a structure that built upwards from a foundation
of rhythm instruments, you can picture your mix as a continuum of frequencies
from low to high. Each instrument (the human voice included) has a certain range
of frequencies it generates, a smaller subset of which really define the sound
of that instrument.
Multiple instruments generating the same range of frequencies will compete, masking each other’s sound. Your mix will seem “busy” at those frequencies, and clarity will suffer until you reduce one or more instrument’s output in the offending range. In most cases, the solution for establishing instruments into their own frequency areas is equalization.
After listening critically for areas of competition between instruments, you can cut specific frequency bands on one or more channels to reduce sonic clutter. For example, imagine a simple worship band consisting of drums, electric bass, keyboard/synth, acoustic guitar, four backing vocalists and a vocal leader.
In this example, the combination of bass guitar, sampled piano and acoustic guitar is causing a major traffic jam in the low-mid frequency range. The bass guitar is the first to go—cutting several dB around 250 Hz reduces the instrument’s low-mid output without changing its fundamental tone.
The acoustic guitar, strummed with a pick, complements the mix most with the high-frequency “zing” of the strings—almost making it a percussive element. The guitar’s lowest frequencies, down around 150 Hz, are only causing acoustic clutter. Hence reducing the bass from the acoustic guitar, even with a dramatic low-frequency cut, will only improve the sound of the overall mix. The acoustic guitar is then mainly heard in the 1 kHz to 8 kHz range, where there are far fewer instruments competing.
In this ensemble, the acoustic piano is best suited to filling out the low-mid frequencies above the bass guitar, as well as adding some brighter accents up with the acoustic guitar. The synth string pad will sit nicely in the middle range between piano and acoustic guitar. Synth sounds can also tend to be heavy in the low midrange, and may require some EQ to keep them from competing with piano and bass.
With the instruments balanced across the frequency spectrum, it will be much easier to create a pleasing blend of vocals on top.
This approach to “narrowing” sounds into appropriate ranges and eliminating buildup becomes all the more effective as the number of instruments increases. Sometimes, an instrument or section needs to be cut down to its sonic essence, with less crucial frequencies reduced by several dB. For a visual representation of this mixing approach, see figure 2.
Build It Your Way
Odds are, you already have an approach to mixing that you’ve found success
with. Don’t abandon it. But the next time you sit behind the board, try
one of these methods and gauge the results. If you usually mix from the bottom
up, try starting with the main vocalist and work your way down. If you’ve
never thought about how sounds interact across the frequency spectrum, try to
listen with this concept in mind.
You may prefer the new method, and your mixes will improve. At the very least, you’ll gain some new insights into why you prefer to mix the way you do.
Loren Alldrin is a church sound engineer, consultant and
trainer.
