Using EQ (Equalizer) in Video Editing

Introduction to EQ in Video Editing

Equalization (EQ) is the process of adjusting the relative loudness of specific frequency ranges within an audio signal. It is arguably the most important tool in audio mixing, used to correct problems (like boomy bass or harsh mid-range) and creatively shape the tone of dialogue, music, and sound effects.

While many video editors focus primarily on picture, poor audio quality is one of the most common reasons viewers stop watching a video. A basic understanding of EQ will dramatically improve the quality of your productions, whether you're working on a YouTube video, documentary, or short film.

Understanding the Frequency Spectrum

Sound is made up of vibrations at different frequencies, measured in Hertz (Hz) and kilohertz (kHz). The human hearing range is roughly 20 Hz to 20,000 Hz (20 kHz). For practical audio work, the spectrum is divided into regions:

Learning to identify and address problems in each region is the core of practical EQ work.

Types of EQ

Parametric EQ

The most versatile and widely used type in professional video work. A parametric EQ lets you control:

• Frequency — the center point of the adjustment (e.g., 200 Hz)
• Gain — how much to boost (+) or cut (-) at that frequency, in decibels (dB)
• Q (bandwidth) — how wide or narrow the affected range is. A high Q affects only a narrow band; a low Q affects a broad swath of frequencies.

Graphic EQ

A fixed-band equalizer with sliders at set frequency intervals (often 10 or 31 bands). Less precise than parametric but intuitive for quick adjustments.

High-Pass and Low-Pass Filters

• A high-pass filter (HPF) removes everything below a set frequency. Essential for removing rumble, HVAC noise, and low-frequency hum from dialogue.
• A low-pass filter (LPF) removes everything above a set frequency. Used to reduce high-frequency hiss or to tame harsh sounds.

Shelf Filters

• A low shelf boosts or cuts all frequencies below a set point equally.
• A high shelf boosts or cuts all frequencies above a set point equally. Useful for adding "air" (brightness) or reducing harshness.

Applying EQ in Adobe Premiere Pro

1. In the Effects panel, search for Parametric Equalizer or use Audio Track Mixer for built-in EQ per track.
2. Drag the Parametric Equalizer effect onto a clip or an audio track.
3. Double-click the effect in the Effect Controls panel to open the full EQ interface.
4. Enable individual bands by clicking their activation buttons.
5. Drag band handles in the frequency graph or enter values numerically.

Premiere Pro also integrates with Adobe Audition for more advanced EQ work via the Edit Clip in Audition command.

Applying EQ in DaVinci Resolve

Edit Page (Inspector)

1. Select an audio clip and open the Inspector.
2. Expand the EQ section — a built-in 6-band parametric EQ is available.
3. Enable bands and drag handles in the visual frequency display.

Fairlight Page

DaVinci Resolve's Fairlight page is a full professional audio workstation:

1. Switch to the Fairlight page.
2. Each channel strip has a built-in 4-band EQ section — click the EQ display to expand it.
3. For more complex EQ, insert a plugin via the channel strip's Effects insert.
4. The Fairlight EQ offers HP/LP filters plus up to 6 parametric bands with full Q control.

Applying EQ in Adobe Audition

Audition is Adobe's dedicated audio workstation, often used in tandem with Premiere via Dynamic Link:

1. Open a clip in Audition via Edit > Edit Clip in Adobe Audition.
2. Apply the Parametric Equalizer from the Effects > Filter and EQ menu.
3. The full-featured EQ displays a large frequency graph with up to 10 bands.
4. Use the Spectral Frequency Display to visually identify problem frequencies — peaks and dips show up as color intensity in the spectrogram.

Practical EQ Techniques

Cleaning Up Dialogue

This is the most common EQ task in video editing.

1. High-pass filter at 80–120 Hz: Nearly all dialogue problems below this range are noise, not voice. Roll off everything below 100 Hz to remove handling noise, HVAC rumble, and low-end mud.
2. Cut the "muddy" range (200–400 Hz): If dialogue sounds thick or boxy, narrow-Q cuts of 2–4 dB in the 200–400 Hz range clean it up.
3. Boost presence (2–5 kHz): A gentle boost in this range increases clarity and intelligibility — the listener can understand words more easily.
4. De-ess sibilance (5–8 kHz): Harsh "s" and "sh" sounds are often exaggerated by microphones. A narrow cut at the offending frequency (find it by sweeping a narrow boost until the harshness peaks, then cut) tames sibilance.

EQing Background Music

Music already has its own EQ balance from its producer/mixer. Your job is to ensure it doesn't conflict with dialogue:

1. Apply a gentle high-pass filter at 60–80 Hz to remove sub-bass that adds no musical value in a video context but uses headroom.
2. If music competes with dialogue in the 1–4 kHz range (the vocal presence zone), apply a gentle broad dip (-2 to -4 dB) in that range on the music track when dialogue is present.
3. This technique — called EQ ducking — is subtler and more musical than simply turning down the music volume.

Fixing Problem Room Sounds

Rooms with hard surfaces (bare walls, tile floors) create unwanted reflections that make dialogue sound "roomy" or hollow:

• A narrow cut around 300–500 Hz often reduces the "boxy" room coloration.
• Experiment with narrow cuts (high Q) by sweeping through the 300 Hz–1 kHz range to find the resonant frequency of the room, then cut it.

Common Mistakes to Avoid

• Boosting instead of cutting — always try cutting problem frequencies before boosting others. Cuts are more natural-sounding than boosts.
• Over-EQing — small adjustments (1–3 dB) go a long way. Extreme EQ settings usually create more problems than they solve.
• Not using a high-pass filter — failing to apply an HPF to dialogue is one of the most common beginner errors. Always high-pass your voice tracks.
• EQing in a bad listening environment — if your room has poor acoustics or you're using consumer earbuds, you cannot make accurate EQ decisions. Use quality studio headphones when in doubt.

Conclusion

EQ is not about making sound "better" in an abstract sense — it is about solving specific problems and carving space for each element in your mix. Start with high-pass filters on dialogue, make targeted cuts rather than broad boosts, and listen critically at moderate volume levels. With practice, identifying and addressing frequency problems becomes second nature, and your audio will sound markedly more professional.