The Critical Role of Equalization in Mixing

Extending the frequency range during mixing
Equalizers as the primary tool for shaping tone
Aiming for a natural sound, even with unconventional methods
Less is more: experienced mixers’ approach to EQ

Extending the frequency range of tracks in mixing compensates for limitations from the recording phase, due to various factors like recording environment and instrument sound.
- Frequency Range Great mixers make sure that all audible frequencies are represented. The “tall” dimension in mixing refers to ensuring all frequencies are properly represented, especially the sparkly highs and powerful lows
Equalizers are pivotal in making tracks sound bigger, fatter, brighter, and clearer. Their effective use differentiates skilled mixers from novices.
Allen Sides emphasizes the goal of achieving a natural sound, regardless of the unconventional methods required, highlighting the significance of a trustworthy reference point.
Joe Chiccarelli’s statement reflects a minimalist approach to EQ, where less is often more, yet not hesitating to make bold adjustments when necessary.

Objectives of Using Equalization

Enhancing clarity and definition of instruments
Amplifying the size and presence of the mix
Giving each instrument its own frequency space

Essential EQ Techniques and Tips

Use narrow Q for cuts, wide Q for boosts
Roll off lows to cut through; roll off highs to blend in
Sparse mixes need wider EQ; dense mixes need tighter control
Two small boosts sound more natural than one large boost
Always check your EQ choices in the context of the full mix

Using a narrow Q for cutting helps isolate and remove specific problem frequencies without affecting the surrounding sound, while a wide Q for boosting gently enhances a broader range, ensuring a more natural effect.
Rolling off the bottom end can help an instrument cut through the mix by reducing muddiness, whereas rolling off the top end can help it blend better by softening its presence.
In arrangements with fewer instruments, allowing each instrument more sonic space can lead to a fuller, richer sound. Conversely, in dense mixes, scaling back the presence of each instrument is crucial for clarity and cohesion.
Applying modest EQ boosts at two different frequencies can provide a more balanced enhancement than a significant boost at a single frequency, leading to a more nuanced sound.
An instrument may sound excellent on its own when EQ’d in isolation, but it’s important to ensure that these adjustments still allow it to sit well within the full context of the mix, highlighting the importance of contextual EQ adjustments.

Equalization for Enhanced Definition

Even well-recorded material can sound lifeless without EQ
Subtractive EQ: cutting frequencies that mask clarity
Key frequency ranges for subtractive EQ
Less is more: cut before you boost

Overemphasis or severe attenuation of certain frequencies can diminish the vibrancy and clarity of even well-recorded source material, often necessitating EQ adjustments for improved definition.
Subtractive EQ focuses on eliminating frequencies that obscure an instrument’s clarity, particularly effective in the lower midrange (400 to 800Hz) to reduce “boxiness” and in the presence range (3kHz to 6kHz) to enhance definition.
Two critical frequency ranges for subtractive equalization—200Hz to 600Hz and 2kHz to 4kHz—are often impacted by the proximity effect and microphone presence boosts, respectively. Adjusting these can significantly improve natural sound quality.
Bruce Swedien’s advice underscores the importance of listening before EQing, advocating for a less-is-more approach. Attenuating frequencies rather than boosting them is recommended to avoid undesirable phase shifts and maintain the natural timbre of the instruments.

Method One: Definition

Starting with your EQ flat, remove all the bottom end below 100Hz by turning the low-frequency control to full cut.
Using the rest of your EQ, tune the mid-upper midrange until the sound is thick yet distinct.
Round it out with a supporting lower-mid tone to give it some body.
Slowly bring up the mud-inducing bottom end enough to move air, but not so much as to make the sound muddy.
Add some high-frequency EQ for definition (see Figure 7.2).

Method Two: Equalize for Size

Set the Boost/Cut control to a moderate level of Boost (8 or 10dB should work).
Sweep through the frequencies in the bass band until you find the frequency where the sound has the desired amount of fullness.
Adjust the amount of Boost to taste. Be aware that too much Boost will make the sound muddy.
Go to the frequency either half or twice the frequency that you used in Step 2 and add an amount of that frequency as well. Example: If your frequency in Step 2 was 120Hz, go to 60Hz and add a dB or so as well. If your frequency was 50Hz, go to 100Hz and add a bit there (see Figure 7.3).

Method Three: Juggling frequencies

Don’t EQ instruments in solo — always listen in context
Give each instrument its own frequency space
Balancing the rhythm section and vocals
Step-by-step process for adding elements to the mix

Frequency Juggling for Instrument Clarity

Rhythm section foundation
- Start with kick/bass relationship
- Ensure kick has punch (80-100Hz) while bass has depth (40-80Hz)
- Create separate spaces for snare (200-400Hz for body, 3-5kHz for snap)
Instrument frequency assignments
- Bass: 40-200Hz fundamental, 700-1kHz for attack
- Kick: 60-100Hz for thump, 2-4kHz for beater click
- Snare: 200Hz for body, 3-5kHz for crack
- Guitar: 300-500Hz for body, 1.5-3kHz for presence
- Piano: 80-300Hz for low notes, 1-2kHz for clarity
- Vocals: 100-300Hz for warmth, 2-5kHz for intelligibility
Practical techniques
- Create 3dB dips in competing instruments where another needs to shine
- Boost instruments in different octaves (e.g., guitar at 1.5kHz, vocals at 3kHz)
- Use narrow Q settings for surgical cuts, wider for natural boosts
- Check mono compatibility to ensure frequency separation works in all playback systems

Golden Rules and Trouble Frequencies

Cut at 250Hz to reduce muddiness
Cut at 500Hz to eliminate honkiness
Cut to improve sound quality; boost to change character
You can’t boost what isn’t there

Frequency	Problem
200Hz	Mud
300-500Hz	Boxiness
800Hz	“Cheap” sound
1-1.5kHz	Nasality
4-6kHz	Presence (lack = dull)
10kHz+	Air

EQ Golden Rules

Cut at 250Hz to reduce muddiness
Cut at 500Hz to eliminate honkiness
Cut to improve sound quality, boost to change character
Can’t boost what isn’t there in the original recording

Technical Approach

Use narrow Q for cuts (surgical precision)
Use wide Q for boosts (natural enhancement)
Apply high-pass filters to most tracks to clean low end
EQ order matters: before dynamics if compressor response needs improvement

Trouble Frequency Details

The 200Hz area is critical for achieving the right balance between fullness and clarity. Excess can lead to a muddy mix, while too little may result in a thin sound.
Frequencies between 300 and 500Hz are notorious for causing boxiness, particularly noticeable in lower quality microphones and certain drums, often requiring careful reduction.
The 800Hz range is associated with a cheap, tinny sound reminiscent of low-quality speakers, necessitating careful adjustment to avoid an overly “budget” audio quality.
Vocal tracks often suffer in the 1k to 1.5kHz range, leading to a nasal sound. Adjusting this range can significantly improve vocal clarity and naturalness.
The presence range (4kHz to 6kHz) is essential for definition and clarity. Underutilization leads to a dull sound, while overemphasis can cause harshness or sibilance.
Frequencies above 10kHz add “air” and a sense of space to recordings, enhancing realism and breathiness, especially important in vintage microphone recordings or to simulate such a quality with modern gear.

Bass/Kick Relationship

Kick: 60-80Hz for thump, 60-120Hz for small speaker audibility, 1-4kHz for attack
Bass: 80-250Hz for presence, allowing kick to dominate below

Balancing Bass and Drums for a Punchy Mix

Separate frequencies: kick (60-80Hz), bass (80-250Hz)
Kick EQ: boost 60-120Hz for speakers, boost 1-4kHz for attack, cut 200-600Hz boxiness
Bass EQ: boost 800Hz for clarity, use genre-specific boosts
Fix levels before reaching for EQ; compress together (3-6dB reduction)
High-pass kick at ~30Hz, bass at ~50Hz to prevent mud

Bass & Drums Balance for Punch

Frequency Separation Techniques

Kick fundamentals: 60-80Hz for initial impact, high-pass at 30Hz
Bass fundamentals: Best in 80-250Hz range, high-pass at 50Hz
Strategic EQ carving: Create dips in one instrument where the other needs prominence

Kick Drum Enhancement

Small speaker audibility: Boost 60-120Hz band
Attack definition: Add 1-4kHz for beater click
Remove boxiness: Apply 2-4dB cut between 200-600Hz
Genre-specific: Metal kicks (+3kHz), club kicks (emphasize 200-300Hz)

Bass Guitar Treatment

Clarity boost: Add 800Hz (2-4dB) for string definition
Low-cut technique: Apply high-pass at 250Hz, then find sweet spot with narrow 4dB boost between 80-180Hz
Rock bass: +50-100Hz for bottom, -400-800Hz dip, +1.5-2.5kHz for midrange presence
Hip-hop/EDM: Preserve sub-frequencies (30-60Hz)

Professional Workflow Solutions

Level management: Adjust fader balance before reaching for EQ
Compression strategies:
- Even out bass notes with 4:1 ratio, medium attack
- Bus both instruments to shared compressor (3-6dB reduction)
Phase alignment: Time-align DI and amp signals (typically 2-8ms adjustment)
Reference comparison: A/B with commercial tracks at matched volume

Guitar EQ Techniques

Fatten tone by boosting midrange (400Hz) for warmth without sacrificing clarity
Cut through the mix with strategic 5-8kHz boost while rolling off bottom end
Enhance presence with 1-5kHz boost; add string articulation at 10kHz
Filter appropriately (high-pass to avoid bass competition, low-pass below 8kHz)
Balance with other instruments through selective frequency enhancement

Achieving Vocal Depth and Clarity with EQ

Subtractive EQ: Cut boxiness (200-800Hz) and problem resonances (2-4kHz)
High-Frequency Boosts: Enhance presence (4-6kHz) and air (10kHz+) for definition
EQ on Effects: Scoop mids (2kHz) in reverbs/delays; roll off below 200Hz/above 10kHz
De-essing: Compress sibilant frequencies (3-10kHz) for smooth “S” sounds
To achieve vocal depth and clarity using EQ, consider techniques such as subtractive equalization, boosting high frequencies, utilizing EQ curves on reverbs and delays, and addressing sibilance.
Key techniques to consider:
- Subtractive Equalization: Reduce frequencies that mask definition, especially in the lower midrange (400Hz to 800Hz), which can add a “boxy” quality. You can sweep through frequencies between 200Hz and 600Hz, as well as between 2kHz and 4kHz, to find the areas to cut.
- Boosting High Frequencies: Add high-frequency EQ for definition. The 4kHz to 6kHz range (presence) is often underutilized and can prevent a track from sounding dull. Too much, however, can make the vocal sound thin. Also, frequencies above 10kHz (air) can add clarity and “realness”.
- EQ Curves on Reverbs and Delays: When using reverb on vocals, create an EQ scoop in the midrange around 2kHz to keep the effect out of the way of the vocal’s consonants. You can roll off the high and low ends of the frequency spectrum around 200Hz and 10kHz to prevent muddiness or excessive prominence. To make an effect stand out, brighten it up; to make it blend, darken it by filtering out the highs.
- De-essing: Use a de-esser to compress the “S” frequencies, which typically fall between 3kHz and 10kHz, to combat sibilance. This can be done either with dedicated hardware or software, or by using a compressor with an equalizer plugged into the sidechain.
Additional techniques and considerations:
- Enhancing Consonants: Accentuate consonants by boosting 2kHz to 4kHz, which makes the vocal seem closer.
- Dealing with problem resonances: Dynamic EQ can contain sporadic, narrow-bandwidth frequency peaks, which can help when a singer creates different timbres and vowel sounds.
- Creating space for vocals: Reduce the levels of cymbal frequencies above 5kHz or exaggerate those frequencies in the vocal sound to retain the same vocal sound against cymbals.
- EQ for Distance: Brighter sounds are perceived as closer, while duller sounds are perceived as farther away.
- Mono Compatibility: When widening the vocal’s stereo image, ensure it remains mono-compatible.