Analog and digital sources have different characteristics that affect how they sound and how they respond to EQ. Analog sources, such as vinyl records, tapes, or live instruments, tend to have more warmth, saturation, and harmonic distortion, which can add richness and depth to the sound. Digital sources, such as CDs, MP3s, or synthesized sounds, tend to have more clarity, accuracy, and dynamic range, which can make them sound more crisp and detailed. However, analog sources can also suffer from noise, hiss, and degradation, while digital sources can suffer from aliasing, clipping, and quantization errors. These artifacts can make the sound harsh, dull, or thin, and require careful EQ to fix or enhance.
There are different types of EQ that you can use to address the tonal and spectral differences between analog and digital sources. The most common ones are parametric, graphic, and linear-phase EQ. Parametric EQ allows you to adjust the frequency, gain, and bandwidth (or Q) of each band, giving you precise control over the shape of the curve. Graphic EQ divides the frequency spectrum into fixed bands, each with a slider to boost or cut the gain. Linear-phase EQ preserves the phase relationship between the frequencies, avoiding phase distortion and artifacts. Each type of EQ has its advantages and disadvantages, depending on the source and the goal.
Before you apply EQ to your sources, you need to have a clear goal in mind. What are you trying to achieve with EQ? Do you want to correct a problem, enhance a feature, or create a contrast? Depending on your goal, you can use different EQ techniques and strategies. For example, if you want to correct a problem, such as noise, hiss, or hum, you can use a high-pass or low-pass filter to remove the unwanted frequencies. If you want to enhance a feature, such as warmth, brightness, or presence, you can use a boost or cut to emphasize or de-emphasize certain frequencies. If you want to create a contrast, such as making the bass more prominent or the vocals more clear, you can use a notch or a shelf to create a difference between the sources.
To use EQ effectively and efficiently, it's important to use your ears instead of relying on the visual display. Try referencing other tracks that have a similar style or genre to get an idea of how they use EQ. Make subtle adjustments and avoid extreme boosts or cuts. A/B testing is also useful to compare the original and the EQed source. Finally, don't forget to use automation to adjust the EQ according to the changes in the source or context.
Something to keep in mind while using EQ is that it isn’t just to balance sounds sonically but can be used to create effects, create depth, and create a new feeling within a mix of sounds or a song. A few examples - subtracting the highs can make things sound further back. -Rolling off highs and lows will leave you with just the mids for a “telephone” effect. - boosting the mids around 1kHz-2kHz can add a feeling of more energy.
To illustrate how you can use EQ to address the tonal and spectral differences between analog and digital sources, here are some examples of common scenarios and solutions. For instance, if you have a vinyl record that sounds warm and rich but also noisy and muddy, you can use a high-pass filter to remove the low-frequency noise and rumble, a notch filter to cut out the mid-frequency hiss and hum, and a gentle boost around 10 kHz to add some brightness and sparkle. If you have a synthesized bass that sounds crisp and punchy but also thin and sterile, try using a low-shelf filter to boost the low frequencies around 100 Hz, a saturation or distortion plugin to add some harmonic content, and a subtle cut around 500 Hz to reduce muddiness. If you have a live vocal that sounds natural and expressive but also dull and distant, use a low-pass filter to remove high-frequency noise and sibilance, a boost around 3 kHz to add presence and clarity, and a compressor or limiter to reduce dynamic range.
Ears before Eyes: Listen to each audio element in its original format before making any EQ changes. How clean is it? Where will it sit in the mix? What else is on that frequency? There are many things to consider BEFORE EQ is used. Make sure you have all the audio elements lined up in their rough original format before you start to EQ. In this day and age it is far better to get the purest audio from source and then just tweak the ranges to prevent frequency clashes that dampen the depth and clarity overall. It's easy to get lost in the Parametric Paradigm but that's the road to Muddy Town and the days of cleaning up old samples should be over. Use EQ for sparkle and drum power. Less should be more