EQ
Module ID: fx.eq
Category: Effects
Header Color: Purple
The EQ module
Description
The 3-Band Parametric EQ allows precise control over the frequency content of your signal. Each band can boost or cut a specific frequency range with adjustable center frequency and bandwidth (Q).
EQ is essential for:
- Shaping tone and timbre
- Fixing frequency problems
- Making sounds fit in a mix
- Creative sound design
Inputs
| Port | Signal Type | Description |
|---|---|---|
| Input | Audio (Blue) | Signal to be equalized |
Outputs
| Port | Signal Type | Description |
|---|---|---|
| Output | Audio (Blue) | Equalized signal |
Parameters
Low Band
| Knob | Range | Default | Description |
|---|---|---|---|
| Low Freq | 20 Hz - 500 Hz | 100 Hz | Center frequency |
| Low Gain | -12 dB to +12 dB | 0 dB | Boost or cut amount |
| Low Q | 0.5 - 10.0 | 1.0 | Bandwidth (higher = narrower) |
Mid Band
| Knob | Range | Default | Description |
|---|---|---|---|
| Mid Freq | 200 Hz - 5 kHz | 1 kHz | Center frequency |
| Mid Gain | -12 dB to +12 dB | 0 dB | Boost or cut amount |
| Mid Q | 0.5 - 10.0 | 1.0 | Bandwidth (higher = narrower) |
High Band
| Knob | Range | Default | Description |
|---|---|---|---|
| High Freq | 1 kHz - 20 kHz | 8 kHz | Center frequency |
| High Gain | -12 dB to +12 dB | 0 dB | Boost or cut amount |
| High Q | 0.5 - 10.0 | 1.0 | Bandwidth (higher = narrower) |
Understanding EQ
Frequency Ranges
| Range | Frequency | Character |
|---|---|---|
| Sub | 20-60 Hz | Felt more than heard, rumble |
| Bass | 60-250 Hz | Weight, warmth, punch |
| Low Mid | 250-500 Hz | Body, muddiness |
| Mid | 500 Hz - 2 kHz | Presence, boxiness, clarity |
| Upper Mid | 2-5 kHz | Definition, attack, harshness |
| High | 5-10 kHz | Brightness, sibilance, air |
| Air | 10-20 kHz | Sparkle, air, presence |
Q (Bandwidth)
Q controls how wide or narrow the affected frequency range is:
- Low Q (0.5-1.5): Wide, gentle curves, affects many frequencies
- Medium Q (2-4): Focused but still musical
- High Q (5-10): Surgical, narrow cuts, affects specific frequencies
Boost vs Cut
General rule: Cut narrow, boost wide
- Cuts are good for removing problem frequencies (use higher Q)
- Boosts add character but can sound unnatural (use lower Q)
Usage Tips
Removing Mud
Clean up muddy sounds:
Mid Freq: 300 Hz
Mid Gain: -3 to -6 dB
Mid Q: 2.0
This is the common "mud" frequency range.
Adding Warmth
Add body and warmth:
Low Freq: 100 Hz
Low Gain: +3 dB
Low Q: 1.0
Adding Presence
Make sounds cut through:
High Freq: 3 kHz
High Gain: +3 dB
High Q: 1.5
Telephone Effect
Dramatic filtering for effect:
Low Freq: 300 Hz, Gain: -12 dB
High Freq: 3 kHz, Gain: -12 dB
Cuts lows and highs, leaving only mids.
De-Boxing
Remove boxy sound from recordings:
Mid Freq: 400-600 Hz
Mid Gain: -3 dB
Mid Q: 2.5
Air and Sparkle
Add high-end shine:
High Freq: 12 kHz
High Gain: +2 dB
High Q: 0.7
Wide boost adds open, airy quality.
Finding Problem Frequencies
- Set one band's Q to high (5.0+)
- Boost the gain to +6 dB
- Sweep the frequency while listening
- When you hear the problem clearly, reduce gain to cut
Subtractive EQ
Start by cutting problem frequencies rather than boosting:
- Often sounds more natural
- Less likely to cause clipping
- Maintains headroom
Frequency Slot Carving
Give each sound its own space:
Bass: Boost 80 Hz, cut 300 Hz
Synth: Cut 80 Hz, boost 500 Hz
Lead: Cut 500 Hz, boost 2 kHz
Each element has its own frequency territory.
Frequency Cheat Sheet
Problem Frequencies
| Problem | Frequency | Solution |
|---|---|---|
| Rumble | < 40 Hz | Cut |
| Boomy | 100-200 Hz | Cut narrow |
| Muddy | 250-400 Hz | Cut |
| Boxy | 400-600 Hz | Cut |
| Nasal | 800 Hz - 1 kHz | Cut |
| Harsh | 2-4 kHz | Cut narrow |
| Sibilant | 5-8 kHz | Cut narrow |
Enhancement Frequencies
| Quality | Frequency | Action |
|---|---|---|
| Weight | 80-100 Hz | Boost |
| Warmth | 200 Hz | Boost wide |
| Body | 300-500 Hz | Boost carefully |
| Presence | 2-4 kHz | Boost |
| Clarity | 5-7 kHz | Boost |
| Air | 10-15 kHz | Boost |
Connection Examples
Channel Strip
[Sound] ──> [EQ] ──> [Compressor] ──> [Output]
Post-Effect Processing
[Synth] ──> [Distortion] ──> [EQ] ──> [Output]
EQ after distortion can tame harsh frequencies.
Reverb Shaping
[Sound] ──> [Reverb] ──> [EQ] ──> [Output]
Cut lows from reverb to prevent mud.
Tips
- Cut before boost: Try cutting unwanted frequencies first
- Less is more: Small EQ moves often sound best
- Use your ears: Trust what sounds good, not what looks right
- A/B test: Bypass the EQ to compare processed and original
- Watch levels: Boosting increases overall level
Related Modules
- SVF Filter - Dramatic filtering
- Compressor - Dynamics after EQ
- Distortion - Harmonics to then EQ
- Reverb - Shape reverb tone with EQ