EQ shapes the tone of each sound so it fits with everything else. Most mixing problems are solved with a few precise cuts rather than big boosts. This hub collects every Solar Heavy Studios guide on eq in one place, grouped by subtopic, so you can learn in order or jump straight to the problem you have today.
A learning path through EQ
Start with the frequency spectrum itself: what lives in the sub bass, the low mids where mud and boxiness collect, the presence range, the region where harshness appears, and the air band at the top. Then learn the filter shapes: high pass filters, low and high shelves, bell filters, notch filters, and the role of Q factor. Practise EQ sweeping to find problems, and learn the difference between parametric, graphic and tilt EQs. Finally, study frequency masking between instruments, dynamic EQ for problems that come and go, and the trade-offs between minimum phase and linear phase designs.
The guiding principle: EQ is for making sounds fit together. A sound that is perfect on its own may need cuts to sit in a full mix, and a sound that seems thin when soloed may be exactly right in context. Make most decisions with the whole mix playing.
Start here
- Piano Eq
- Bass Guitar Eq
- Eq Tips Tricks
- Acoustic Guitar Eq
- Eq Frequency Guide
- Eq Electric Guitar
- Eiosis Air Eq Review
- Vocal Eq Compression
Free tools and quick guides
- EQ Cheat Sheet (free tool: EQ Frequency Chart)
Subtopics in this hub
Each subtopic has a short explanation below. Where a full guide already exists on the site, it is linked; the rest are being written.
EQ sweeping
Sweeping means boosting a narrow bell filter and moving it across the spectrum to find resonances or ugly frequencies, then cutting at the spot that sounds worst. It is a useful learning tool, but every frequency sounds bad when boosted heavily, so it is easy to over-cut. Sweep with a moderate boost, cut only what stood out clearly, and confirm the change with the full mix playing.
Q factor
Q sets the bandwidth of a bell or notch filter. A high Q affects a narrow range of frequencies and is used for surgical cuts such as removing a ringing resonance. A low Q affects a broad range and sounds more natural for tonal shaping. Some EQs show bandwidth in octaves instead; a Q of about 1.4 corresponds to roughly one octave.
Air band
The air band usually refers to the very top of the audible spectrum, roughly 10 kHz and above. A gentle high shelf here adds openness and sparkle to vocals, acoustic guitars, cymbals and full mixes. Boost subtly, because too much air makes sibilance and noise obvious. Some EQs designed for this range use smooth shelves that sound less harsh than a standard boost.
Bell filter
A bell (or peaking) filter boosts or cuts around a centre frequency, with Q controlling how wide the bell is. It is the most flexible EQ shape, used for everything from wide tonal boosts to narrow cuts on resonances. Most parametric EQs offer several bell bands so you can shape a sound precisely.
Boxiness
Boxiness is a hollow, cardboard-like quality, usually somewhere between about 300 and 600 Hz, common on drums, vocals recorded in small rooms and acoustic guitars. A moderate cut in this range often makes a sound clearer and more open. Find the exact spot by sweeping, because it varies with the source and room.
Dynamic EQ
Dynamic EQ combines an EQ band with a compressor or expander, so the band only cuts or boosts when the signal in that range crosses a threshold. It is ideal for problems that come and go, like a harsh note in a vocal, a boomy bass note, or sibilance. Because it acts only when needed, it avoids dulling the sound the rest of the time.
Read the full guide: What is a Dynamic EQ Plugin
Frequency masking
Masking happens when two sounds share the same frequency range and the louder one hides the quieter. Kick and bass, vocals and guitars, and pads and keys are common examples. Solve it by deciding which sound leads in each range, then cutting a little from the other, panning them apart, or using sidechain or dynamic EQ to make space only when both play.
Read the full guide: Frequency Masking Insights And Pro Tips
Graphic EQ
A graphic EQ has fixed frequency bands, each with its own fader, often in octave or third-octave spacing. It is quick for broad tonal shaping and is common in live sound for tuning speakers to rooms. Its fixed bands and bandwidths make it less precise than a parametric EQ for detailed mix work.
Harshness
Harshness is an aggressive, fatiguing sound typically in the upper mids, roughly 2 to 5 kHz, where our ears are most sensitive. It comes from bright mics, distorted guitars, cymbals and over-compressed vocals. Gentle cuts, dynamic EQ or a de-esser style processor can help, and the best fix is often at the source with mic choice and placement.
Read the full guide: How To Fix Harshness When Mastering Music
High pass filter
A high pass filter removes frequencies below a cutoff while letting higher ones through. Using it on vocals, guitars, overheads and synths that do not need deep bass cleans up rumble and leaves room for kick and bass. Set the cutoff by ear in context, because filtering too high makes sounds thin. Slope settings decide how steeply the filter cuts.
Read the full guide: How is a High Pass Filter Used in Audio Production?
High shelf
A high shelf boosts or cuts everything above a chosen frequency by the same amount. Boosting adds brightness and air; cutting tames harshness or dulls a sound to push it back in the mix. Shelves sound smooth and natural because they change a whole range evenly rather than a narrow peak.
Linear phase EQ
Linear phase EQ changes frequency balance without shifting the phase relationship between frequencies. That makes it useful in mastering and on parallel or multi-mic sources where phase shifts could cause problems. The trade-offs are latency, higher CPU use and pre-ringing, a faint smear before transients, which is most noticeable with steep low-frequency boosts or cuts.
Low shelf
A low shelf boosts or cuts everything below a chosen frequency. A small boost adds weight to bass or kick; a cut reduces boominess or clears space in a busy mix. Many shelves include a resonant bump near the corner frequency, which can add a pleasing emphasis on classic analog designs.
Minimum phase EQ
Minimum phase EQ is the standard type in most plugins and all analog EQs. It introduces phase shift around the frequencies being changed, which is part of the natural sound of EQ and usually inaudible on a single track. It has no latency and no pre-ringing. Use it for almost all mixing tasks.
Mud frequencies
Mud is a cloudy, congested build-up usually between about 200 and 500 Hz. Each instrument contributes a little energy there, and together they blur the mix. Small cuts in this range on several tracks, especially guitars, pads, pianos and vocals, often clear more than one big cut on the master. Check that you have not thinned the mix too much afterwards.
Notch filter
A notch filter is a very narrow cut that removes a small range of frequencies. It is used to remove hum (for example at 50 or 60 Hz and their harmonics), whistles, feedback and drum resonances. Because it is so narrow, it can remove deep problems with little effect on the overall tone.
Parametric EQ
A parametric EQ gives full control over each band's frequency, gain and bandwidth, plus filter shape. It is the main EQ type for mixing and mastering because it can do both broad tonal shaping and precise surgical work. Most DAWs include a capable parametric EQ with a spectrum display.
Read the full guide: How To Use Parametric Eq
Presence range
The presence range, roughly 2 to 6 kHz, controls how forward and intelligible a sound is. A gentle boost here brings a vocal or guitar closer to the listener; a cut pushes it back. Because human hearing is sensitive in this range, small changes are very noticeable and too much quickly becomes harsh.
Sub bass frequencies
Sub bass generally means frequencies below about 60 Hz. It is felt as much as heard, and many small speakers cannot reproduce it. Keep sub energy controlled and mono, decide whether the kick or the bass owns the lowest range, and check on headphones or a system with a subwoofer, since most rooms make sub bass hard to judge.
Tilt EQ
A tilt EQ raises one end of the spectrum while lowering the other around a centre point, like tilting a seesaw. It is a quick, musical way to make a sound brighter or darker without changing the overall level much. It is useful on buses and in mastering for broad tonal balance.
A practical frequency map
| Range | Approximate frequencies | What it contributes |
|---|---|---|
| Sub bass | 20–60 Hz | Weight and physical impact, felt more than heard |
| Bass | 60–250 Hz | Fullness and the fundamentals of kick, bass and low instruments |
| Low mids | 250–500 Hz | Body and warmth; where mud and boxiness build up |
| Mids | 500 Hz–2 kHz | Tone and character of most instruments; honk and nasal qualities |
| Upper mids | 2–6 kHz | Presence, attack and intelligibility; harshness if excessive |
| Highs | 6–20 kHz | Brightness, sibilance, cymbal shimmer and air |
The ranges overlap and vary by source, so treat them as a starting map rather than fixed rules. Use our free cheatsheets for quick reference while you mix.
Cut first, then boost with intent
Removing what you do not want usually improves clarity more than adding what you think is missing. Cuts reduce masking and free headroom; boosts add level and can increase masking. That does not mean boosts are wrong. A broad, gentle boost to bring out character is often the right move. The habit to build is asking what problem each move solves before you make it, then checking the change in context and at matched loudness.
EQ in context
Soloing helps find problems, but final EQ decisions belong in the full mix. A guitar with its low end filtered may sound thin alone and perfect alongside bass and drums. A vocal with a presence boost may sound harsh solo and just right over dense music. Switch solo off regularly, and judge the result on more than one playback system.
Hearing frequencies
Learning to recognise frequency ranges by ear speeds up mixing more than any plugin. Short daily sessions of frequency ear training, where you guess which band has been boosted, build that skill. Combine them with critical listening to reference tracks to understand how professional mixes balance the spectrum.
EQ starting points by instrument
- Kick drum: find the low-end thump (often 50–100 Hz) and the beater click (often 2–5 kHz); a cut in the boxy low mids can make it punchier.
- Snare: body sits roughly around 150–250 Hz, crack and snap higher up; ringing overtones can be notched out if they distract.
- Bass: decide how the bass and kick share the lows, and use the upper harmonics (around 700 Hz to 2 kHz) to make the bass audible on small speakers.
- Vocals: high-pass to remove rumble, cut mud or boxiness as needed, add presence carefully, and control sibilance with a de-esser rather than a static cut.
- Electric guitars: high-pass to leave space for the bass, and tame fizz at the top if distortion is harsh.
- Acoustic guitar: reduce boom from the body around the low mids, and add a little air for sparkle.
- Pads and keys: often need low-end and low-mid cuts so they support rather than crowd the vocal.
All of these are starting points. Every recording is different, so sweep and listen instead of copying numbers.
Character EQs
Emulations of classic hardware, such as Pultec-style passive EQs and British console EQs, add their own curves and harmonic colour. A Pultec-style low end trick, boosting and cutting at the same low frequency, creates a pleasing shelf with a dip above it. Console EQs often have broad, musical curves that flatter vocals and drums. Use clean parametric EQ for corrective work and character EQs for tone.
Subtractive EQ workflow, step by step
- Set a rough balance with faders before touching EQ, so you know what actually needs fixing.
- High-pass tracks that carry no useful low end, listening for the point where they start to thin out, then back off slightly.
- Listen for the main problem in each important track: mud, boxiness, harshness or a resonance. Cut it with a moderate Q.
- Identify masking between pairs of instruments and give each one priority in a different range.
- Add gentle tonal boosts only where a sound still lacks character in context.
- Bypass each EQ at matched loudness to confirm it improves the mix, then check on another playback system, such as headphones or a phone.
EQ and phase
Every standard EQ shifts phase around the frequencies it changes. On a single track this is normally inaudible. It matters when the same source is captured by several mics, such as a drum kit, or when you blend parallel copies of a signal, because EQ on one path can change how the paths combine. If a multi-mic source gets thinner after EQ, try applying the EQ to a bus instead of individual mics, or use linear phase EQ. Always check the change with every mic in the group playing together, not one at a time.
A good habit is to bypass every EQ periodically at matched level. If the track sounds better or no different without it, the move was unnecessary and can be removed or reduced.
Common mistakes
- Boosting many bands until everything is louder but nothing is clearer.
- Making all EQ decisions with tracks soloed.
- Using very narrow, deep cuts everywhere, which can make sounds hollow.
- High-pass filtering every track so aggressively that the mix loses warmth.
- Relying on the analyser display instead of listening.
- Copying settings from a tutorial without listening in your own track.
FAQ
Should I cut or boost?
Cut problems first, then boost character sparingly.
What is a high-pass filter for?
It removes low frequencies an instrument does not need, cleaning up space for kick and bass.
Should I EQ before or after compression?
Cut problems before the compressor so they do not drive it, and add tonal boosts after if needed. Try both orders and listen.
Do I need expensive EQ plugins?
No. The stock parametric EQ in every major DAW is accurate enough for professional work. Character EQs add colour, not capability.
How much should I boost or cut?
Small moves of one to three decibels often solve tonal balance, while narrow problem cuts can be deeper. If a move needs more than about 6 dB, check whether a different sound, mic position or arrangement choice would solve it better.
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