Introduction: Understanding Frequency Ranges in Mixing
Equalization (EQ) is one of the most powerful tools in audio mixing, allowing you to shape the tonal balance of individual tracks and your overall mix. Understanding frequency ranges and how they affect different instruments is essential for creating clear, balanced, and professional mixes. This guide provides a comprehensive overview of frequency ranges, their sonic characteristics, and specific recommendations for common instruments.
The Complete Frequency Spectrum
| Frequency Range | Name | Sonic Characteristics | Common Instruments |
|---|---|---|---|
| 20-60 Hz | Sub Bass | Felt more than heard, foundational rumble | Synthesizers, sub bass, pipe organ |
| 60-120 Hz | Bass | Fundamental low-end, power, warmth | Kick drum, bass guitar, bass synths |
| 120-250 Hz | Low Mids | Fullness, warmth, boxiness | Bass, lower piano, guitars, kick body |
| 250-500 Hz | Lower Midrange | Muddiness, body, thickness | Guitars, snare body, vocal fullness |
| 500-2 kHz | Midrange | Clarity, presence, definition | Vocals, guitars, snare, piano |
| 2-4 kHz | Upper Midrange | Presence, attack, harshness | Vocal intelligibility, guitar bite |
| 4-10 kHz | High End | Brightness, air, definition | Cymbals, hi-hats, vocal sibilance |
| 10-20 kHz | Air/Brilliance | Shimmer, sparkle, air | Cymbals, overhead mics, ambient space |
Frequency Ranges: Characteristics and Common Issues
Sub Bass (20-60 Hz)
- Characteristics: Foundation, power, physical feeling
- Common Issues: Muddiness, overpowering low end, inaudible on small speakers
- Processing Tips:
- High-pass most elements (except kick and bass) in this range
- Use a spectrum analyzer to check sub content
- Monitor on systems with subwoofers when adjusting
Bass (60-120 Hz)
- Characteristics: Fundamental bass notes, warmth, power
- Common Issues: Boomy, unclear, competing with kick drum
- Processing Tips:
- Choose either kick or bass to dominate (usually kick at ~60-80 Hz, bass at ~80-100 Hz)
- Use sidechain compression to duck bass when kick hits
- Keep bass elements centered in the mix
Low Mids (120-250 Hz)
- Characteristics: Fullness, warmth, resonance
- Common Issues: Muddy, boomy, cluttered mix
- Processing Tips:
- Often needs reduction in many instruments
- Cut narrow bands rather than broad boosts
- Check this range when mix lacks clarity
Lower Midrange (250-500 Hz)
- Characteristics: Body, thickness, boxiness
- Common Issues: Muddy, boxy, unclear mix
- Processing Tips:
- The “mud” frequency range – often benefits from cuts
- Make space for important elements by reducing others
- Most common problematic frequency range in amateur mixes
Midrange (500-2 kHz)
- Characteristics: Presence, clarity, forwardness
- Common Issues: Honky, nasal, too forward
- Processing Tips:
- Critical for vocal intelligibility (~1 kHz)
- Gentle, wide boosts for presence
- Narrow cuts for resonances
Upper Midrange (2-4 kHz)
- Characteristics: Definition, attack, bite
- Common Issues: Harsh, fatiguing, aggressive
- Processing Tips:
- Adds clarity and presence to vocals
- Can create ear fatigue if too prominent
- Often where guitar distortion lives
High End (4-10 kHz)
- Characteristics: Brightness, clarity, detail
- Common Issues: Sibilance, harshness, brittle sound
- Processing Tips:
- De-essing for vocals (~6-9 kHz)
- Adds snap to snare (~5-8 kHz)
- Be careful of buildup across multiple instruments
Air/Brilliance (10-20 kHz)
- Characteristics: Air, shimmer, sparkle
- Common Issues: Hiss, digital harshness
- Processing Tips:
- Subtle shelf boosts for “expensive” sound
- Can add space and dimension to a mix
- Less is more – subtle adjustments make big differences
Instrument-Specific EQ Guide
Kick Drum
| Frequency | Purpose | EQ Move | Notes |
|---|---|---|---|
| 40-60 Hz | Sub impact | Gentle boost | For club/EDM music, may be inaudible on small speakers |
| 60-80 Hz | Thump | Moderate boost | Fundamental power of kick |
| 100-250 Hz | Body | Slight cut or boost | Depends on desired fullness |
| 400-600 Hz | Boxiness | Cut | Reduce boxy resonance |
| 1-3 kHz | Attack | Boost | Click/beater sound |
| 4-8 kHz | Snap | Boost | Modern kick snap/click |
Typical Moves:
- High-pass at 30-40 Hz to remove sub-rumble
- Cut at 400-500 Hz to remove boxiness
- Boost at 60-80 Hz for thump
- Boost at 3-5 kHz for click/attack
Snare Drum
| Frequency | Purpose | EQ Move | Notes |
|---|---|---|---|
| 80-120 Hz | Bottom end | Boost/Cut | For deeper/lighter snare sound |
| 200-400 Hz | Body, fullness | Boost | Adds weight and fullness |
| 400-800 Hz | Boxiness | Cut | Reduces cardboard sound |
| 1-3 kHz | Attack, woodiness | Boost | Stick attack |
| 3-6 kHz | Crack, snap | Boost | Snare wire sound |
| 8-12 kHz | Sizzle | Boost | Adds brightness, air |
Typical Moves:
- High-pass at 80-100 Hz
- Boost around 200-250 Hz for body
- Cut around 400-600 Hz to reduce boxiness
- Boost 5-8 kHz for snap/crack
Hi-Hats & Cymbals
| Frequency | Purpose | EQ Move | Notes |
|---|---|---|---|
| below 300 Hz | Cleaning up | Cut | High-pass to remove rumble |
| 500-1 kHz | Body | Slight boost | Adds weight to thin hats |
| 2-5 kHz | Attack | Boost | Adds definition |
| 5-10 kHz | Brightness | Boost/Cut | Shapes overall tone |
| 10-16 kHz | Sizzle, air | Boost | Adds shimmer and sparkle |
Typical Moves:
- High-pass aggressively (300-500 Hz)
- Cut narrow bands if too harsh around 3-6 kHz
- Gentle shelf boost above 10 kHz for air
Toms
| Frequency | Purpose | EQ Move | Notes |
|---|---|---|---|
| 80-180 Hz | Fullness | Boost | Fundamental (varies by tom size) |
| 200-500 Hz | Body | Boost/Cut | Can add fullness or muddiness |
| 500-800 Hz | Boxiness | Cut | Reduces cardboard sound |
| 1-3 kHz | Attack | Boost | Stick attack |
| 4-7 kHz | Slap | Boost | Enhances attack |
Typical Moves:
- High-pass floor toms at ~70-80 Hz, rack toms at ~100-120 Hz
- Cut 400-600 Hz to reduce boxiness
- Boost fundamentals based on tom size
- Boost 3-5 kHz for attack
Bass Guitar
| Frequency | Purpose | EQ Move | Notes |
|---|---|---|---|
| 40-60 Hz | Sub bass | Boost/Cut | Foundation, depth |
| 60-100 Hz | Bottom end | Boost | Fundamental bass notes |
| 100-250 Hz | Fullness | Boost/Cut | Weight and body |
| 300-500 Hz | Muddiness | Cut | Often needs reduction |
| 700-1 kHz | Definition | Boost | String sound, clarity |
| 2-5 kHz | Attack, presence | Boost | Finger/pick noise, clarity |
Typical Moves:
- High-pass around 30-40 Hz
- Cut 300-400 Hz to reduce mud
- Boost 700-1 kHz for definition
- Gentle boost at 80-100 Hz for fullness
Electric Guitar
| Frequency | Purpose | EQ Move | Notes |
|---|---|---|---|
| Below 80 Hz | Rumble | Cut | High-pass to clean up low end |
| 100-250 Hz | Fullness | Boost/Cut | Warmth, can get muddy |
| 300-500 Hz | Boxiness | Cut | Often needs reduction |
| 500-1 kHz | Body | Boost | Adds thickness |
| 1.5-3 kHz | Presence, bite | Boost | Makes guitar cut through |
| 3-5 kHz | Edge, aggression | Boost/Cut | Can be harsh |
| 5-8 kHz | Definition | Boost | Adds clarity and detail |
Typical Moves:
- High-pass at 80-120 Hz
- Cut 300-500 Hz to reduce mud/boxiness
- Boost 1.5-3 kHz for presence in mix
- Gentle high shelf boost for brightness if needed
Acoustic Guitar
| Frequency | Purpose | EQ Move | Notes |
|---|---|---|---|
| 80-120 Hz | Low end | Cut/Boost | Fullness vs. clarity |
| 150-300 Hz | Body | Boost | Adds warmth |
| 300-500 Hz | Boxiness | Cut | Reduces cardboard sound |
| 600-1 kHz | Honkiness | Cut | Can sound nasal |
| 2-5 kHz | Presence, definition | Boost | String detail, pick attack |
| 6-10 kHz | Brightness | Boost | Adds shimmer |
| 10-16 kHz | Air | Boost | Adds sparkle and life |
Typical Moves:
- High-pass at 80-100 Hz
- Cut 300-500 Hz to clean up boxiness
- Boost 2-4 kHz for presence
- Gentle high shelf boost around 10 kHz for air
Piano
| Frequency | Purpose | EQ Move | Notes |
|---|---|---|---|
| 50-100 Hz | Low end | Cut/Boost | Fullness of lower octaves |
| 100-300 Hz | Warmth | Boost | Body and richness |
| 300-600 Hz | Muddiness | Cut | Often needs reduction |
| 600-1.5 kHz | Body, honkiness | Boost/Cut | Can sound honky if too much |
| 1.5-5 kHz | Presence, hammer | Boost | Brings out hammer attack |
| 5-10 kHz | Brightness | Boost | Adds clarity and definition |
| 10-15 kHz | Air, shimmer | Boost | Adds sparkle and life |
Typical Moves:
- High-pass at 50-80 Hz
- Cut 300-500 Hz to reduce mud
- Boost 2-5 kHz for presence
- Gentle high shelf boost for air
Vocals
| Frequency | Purpose | EQ Move | Notes |
|---|---|---|---|
| Below 80 Hz | Rumble | Cut | High-pass to remove handling noise |
| 100-200 Hz | Fullness | Boost/Cut | Male vocal fundamentals |
| 200-500 Hz | Muddiness | Cut | Often needs reduction |
| 500-1 kHz | Body | Boost | Adds warmth, roundness |
| 1-3 kHz | Presence | Boost | Intelligibility, forward sound |
| 3-5 kHz | Presence, detail | Boost | Makes vocals cut through |
| 5-8 kHz | Sibilance | Cut | De-essing range |
| 8-12 kHz | Air, breath | Boost | Adds brightness and intimacy |
Typical Moves:
- High-pass at 80-120 Hz
- Cut 200-400 Hz to reduce mud
- Boost 2-4 kHz for presence
- Shelf boost above 10 kHz for air
- Consider a de-esser targeting 5-8 kHz
Strings (Violin, Viola, Cello)
| Frequency | Purpose | EQ Move | Notes |
|---|---|---|---|
| 80-150 Hz | Low end (cello, viola) | Boost | Fundamental range for lower strings |
| 150-300 Hz | Body | Boost | Adds warmth |
| 300-500 Hz | Muddiness | Cut | Can sound boxy |
| 500-1 kHz | Body, woodiness | Boost | String resonance |
| 2-5 kHz | Presence, bite | Boost | Bow sound, definition |
| 5-10 kHz | Scratchiness | Cut/Boost | Can sound harsh if too much |
| 10-15 kHz | Air | Boost | Adds detail and space |
Typical Moves:
- High-pass violins at 100-150 Hz, cellos at 60-80 Hz
- Cut 300-500 Hz to reduce boxiness
- Boost 2-4 kHz for definition
- Gentle shelf boost above 10 kHz for air
Brass (Trumpet, Trombone, Saxophone)
| Frequency | Purpose | EQ Move | Notes |
|---|---|---|---|
| 80-150 Hz | Low end (trombone, sax) | Boost | Fundamental range for lower brass |
| 150-500 Hz | Body, warmth | Boost | Adds fullness |
| 500-1 kHz | Honkiness | Cut | Can sound nasal |
| 1-3 kHz | Presence | Boost | Makes brass cut through |
| 3-6 kHz | Brightness, bite | Boost/Cut | Can be harsh or brilliant |
| 6-10 kHz | Air, brightness | Boost | Adds definition |
Typical Moves:
- High-pass trumpets at 100-150 Hz, trombones at 80-100 Hz
- Cut 400-800 Hz to reduce honkiness
- Boost 1-3 kHz for presence
- Careful with 3-6 kHz to avoid harshness
Synthesizers
| Frequency | Purpose | EQ Move | Notes |
|---|---|---|---|
| 30-80 Hz | Sub bass | Boost/Cut | Foundation for bass synths |
| 80-200 Hz | Low end | Boost/Cut | Fundamental range |
| 200-500 Hz | Body, mud | Cut | Often needs reduction |
| 500-2 kHz | Presence | Boost | Helps cut through |
| 2-5 kHz | Definition | Boost | Adds clarity |
| 5-10 kHz | Brightness | Boost | Adds shimmer |
| 10-20 kHz | Air | Boost | Adds sparkle |
Typical Moves:
- Varies widely by synth type
- For bass synths: shape sub region carefully (30-80 Hz)
- For lead synths: emphasize presence (1-5 kHz)
- For pads: reduce mud (200-500 Hz) and add air (10+ kHz)
EQ Techniques and Best Practices
Subtractive vs. Additive EQ
- Subtractive EQ (cutting): Often more natural-sounding, helps create space for other elements
- Additive EQ (boosting): Can add color and character, but may introduce phase issues
- Best Practice: Cut first to create space, then boost if needed
Narrow vs. Wide Q (Bandwidth)
- Narrow Q: Best for surgical cuts of problem frequencies
- Wide Q: Better for musical, gentle tonal shaping
- Best Practice: Use narrow Q (0.5-1.5) for cuts, wider Q (1.0-2.5) for boosts
High-Pass and Low-Pass Filters
- High-Pass Filter (HPF): Removes frequencies below the cutoff point
- Low-Pass Filter (LPF): Removes frequencies above the cutoff point
- Best Practice: Apply HPF to most tracks; gentle slope (6-12 dB/octave) sounds more natural
Complementary EQ
- Cutting frequencies in one instrument where you boost in another
- Creates space for each element in the mix
- Works especially well for instruments competing in the same frequency range
Dynamic EQ
- EQ that responds to input level, like a combination of EQ and compression
- Useful for controlling problematic frequencies only when they become excessive
- Ideal for de-essing, controlling boomy notes, taming harsh frequencies
Mid-Side EQ
- Processing the center and sides of the stereo field differently
- Use on stereo tracks or mix bus
- Common applications:
- Bass clarity: Boost lows in mid, cut lows in sides
- Stereo width: Boost highs in sides, reduce in mid
- Vocal focus: Enhance mids in center, reduce in sides
EQ Strategies for Common Mixing Problems
Muddy Mix
- Cut 200-500 Hz in multiple instruments
- Ensure proper high-pass filtering
- Pay attention to low-mid buildup across tracks
- Create designated space for bass and kick
Harsh or Brittle Sound
- Look for excessive energy in 2-5 kHz range
- Try cutting narrow bands around 3 kHz
- Check for sibilance issues (5-8 kHz)
- Reduce overall high frequency content
Thin or Weak Mix
- Check for over-aggressive high-pass filtering
- Add gentle low-mid boosts (100-300 Hz)
- Enhance fundamental frequencies of key instruments
- Consider saturation or harmonic enhancement
Lack of Clarity
- Ensure each instrument has its own frequency “pocket”
- Cut competing mid frequencies (300-500 Hz)
- Enhance presence range (1-5 kHz) on important elements
- Use automation to emphasize important elements
Dull or Lifeless Mix
- Add gentle high shelf boost (10 kHz+)
- Enhance presence frequencies (2-5 kHz)
- Check for over-filtering of high frequencies
- Consider exciter or saturation plugins
Resources for Further Learning
Recommended Reading
- “Mixing Secrets for the Small Studio” by Mike Senior
- “The Mixing Engineer’s Handbook” by Bobby Owsinski
- “Zen and the Art of Mixing” by Mixerman
Recommended Tools
- Spectrum analyzers: FabFilter Pro-Q, iZotope Insight, Voxengo SPAN
- Reference tracks collection
- Multiple monitoring systems
Advanced Topics to Explore
- Linear phase vs. minimum phase EQ
- Analog EQ emulations
- Dynamic EQ and multiband processing
- Frequency-dependent compression
Remember that these frequency ranges are guidelines, not hard rules. Every source is different, and context matters. Always trust your ears over charts and numbers, and consider how each element works in the context of the full mix.