As you approach the end of the production stage, you will be nearing the mixing stage. Mixing is the process of applying specific techniques and effects to create a comfortable, pleasant representation of frequencies across the spectrum. To become a better mixer, it is all about practice. This not only allows you to familiarize yourself with the process, popular techniques and application but in turn will train your ears to become more sensitive to frequency content, dynamic range and ultimately balance.
A good mix will greatly benefit the mastering process and each decision must be carefully considered. You must know the extent of your repertoire to accurately approach and build a clean, balanced mix. This means, knowing your DAW, tools and techniques thoroughly.
To further understand what a balanced mix sounds like, we must first understand the detectors of sound…our ears. When we perceive sound, it may be any number of combinations of wide and narrow bands of frequencies. This is also referred to as frequency content. Frequency content is largely dictated by the “rigidness” of a signal. A sine wave is the smoothest signal and produces a single frequency output. Any deviation from this perfectly clean “pure tone” wave will see an increase in frequency content. The location of this additional frequency content is again largely dictated by the intricacies of a signal.
If a sine wave is the least harmonically rich, the counterpoint to a sine wave would result in a full frequency spectrum. This describes white noise. White noise is an equal output of energy per frequencies across the spectrum. When our ears listen to white noise, we perceive the sound to be “bright” or “harsh”. Why would an evenly dispersed energy per frequency sound be perceived as bright or harsh? Our ears have hyper sensitivity to particular bands of frequencies as well as a dull sensitivity to other bands of frequencies. This is the primary reason we need to understand our ears, to create a mix that isn’t too “bright”, “harsh”, “dark”, “boomy”, “boxy”, “honky”, etc. These metaphors are just a few terms used to describe sound and its relative frequency content.
31Hz – rumbly
61Hz – bottom
125Hz – boom, warmth
250Hz – full, mud
500Hz – honky
1khz – whack
2kHz – crunch
4kHz – edge
8kHz – sibilance
16kHz – air
Our ears relative frequency sensitivity ranges from 20Hz to 20kHz. Here is a diagram of our ears hyper and dull sensitivity plot.
Notice the large dip in the plot between 2kHz and 7kHz, this shows that we are far more sensitive to frequencies in this range than we are anywhere else in the spectrum. Thus, in the mix, frequencies between 2kHz and 7kHz won’t need to be as high in volume for us to be able to perceive them. The “bright” and “harsh” terms used to describe white noise comes directly from this “excess” output in this particular band of frequencies.
Listening to that same white noise signal, paying attention to low and sub frequency information, we notice a total lack or extreme absence of frequencies in this range. Referring to the previous diagram (equal loudness contour), the plot in the low-end band is far higher. This shows that we are far less sensitive to frequencies in this particular band. Thus, low and sub frequencies need to be pushed higher in volume for our ears to perceive them at the same level as the rest of the spectrum.
A wise engineer once told me to listen in terms of frequency when mixing and you will be able to detect the root of a bad mix far more effectively.
The mixing process can be as rigidly approached as it can be loosely approached. When first starting out mixing, it is important not to lose direction and get lost in the plethora of tools, techniques and effects unless you follow a procedure.
Before diving into the mix-down, we must use a track as a reference point to not only maintain headroom but to also ground our ears after listening fatigue. Listening fatigue occurs at varying rates and degrees depending on what you are listening to and what you are listening on. Monitors are the best to mix on as long as the room in which they are situated is acoustically treated to prevent sound from bouncing off the walls “polluting” our mix coming out of the speakers. Headphones will completely rid of any masking created by reflective sound BUT ears experience fatigue far quicker. Listening fatigue will cause our ears to go through a state of compression, in turn distorting the mix causing incorrect processing and application of techniques. There are pros and cons to all monitoring systems and finding the one most suited to you require research and analysis of equipment specifications, studio setup and other external factors surrounding acoustics.
Reference tracks can be professionally produced songs, an instrument within your project or simply a sample of pink noise. Pink noise is a harmonically rich signal except frequencies are represented with equal energy per octave not equal energy per frequency like white noise. Pink noise is far more comfortable to listen to and more accurately represents our ears sensitivity to frequency content.
We will be breaking up the mixing process into 2 main categories; drum mixing and then music mixing. For drum mixing, we are only focusing on the rhythm section such as the kick, snare, clap, hats, cymbals, percussion and any other rhythmic elements contained within a project. This allows us to create a sturdy rhythm for the rest of our song to move to.
The steps are as follows; levels, pans, EQ, compression, and FX.
Step one is levelling your mix. In this step, simply utilize track faders to bring in your instruments and match them in terms of overall volume and energy. NOTE: keep the master fader at 0dB. If you notice you are clipping at the master fader, you must target clipping from the source, dragging the master fader down to compensate for this situation does not benefit a mix.
To start, drag all track faders down to –inf dB and begin playing the most involved section of your project.
Raise the volume fader of the kick drum so it peaks at -10dB. This will be our reference level, allowing us to mix other elements around it in an attempt not to bury the reference with other instrumentation.
Next, find your second most dominant sound in the drum kit and bring its fader up to match the overall perceived volume and energy in your ears. Do not match the peak level as this will not ensure a balanced mix. Another reason ear training is so important, because our eyes can fault us in a world of sound.
Depending on the drum kit, some sounds may not be designed for the centre or spotlight of the mix, thus, the fader won’t need pushed as high as other more important sounds.
The fader is the single most effective move you can make to change a sounds depth, height, clarity, presence and proximity. This first step of levelling will determine how effective the rest of the mix becomes.