API5500 EQ

EQ — Position 1

5-band semi-parametric equalizer modeled on the API 5500 Dual Channel EQ — a classic console EQ that defined the sound of New York hit recordings through the 1970s–90s. Celebrated for adding energy and punch without harshness.

Quick Start

For a clean mix-bus EQ: touch only the HF shelf (+1.5 dB at 10 kHz for air) and MF bell (−1 dB at 1 kHz to reduce honk). Leave everything else at 0. The API5500 rewards restraint.

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Controls

Control	Range	Default	Description
High-Pass Filter	20 – 600 Hz	Off	12 dB/oct Butterworth HPF. Removes sub rumble before any boosting occurs.
Low Shelf Freq	30 – 200 Hz	100 Hz	Center frequency for the low-frequency shelving filter.
Low Shelf Gain	±15 dB	0 dB	Low-frequency shelving boost/cut. Adds body without boom at moderate boosts.
Low-Mid Freq	100 Hz – 3 kHz	350 Hz	Center frequency of the parametric low-mid band.
Low-Mid Gain	±15 dB	0 dB	Primary mud control: cut 200–400 Hz for clarity; boost 100–150 Hz for warmth.
Low-Mid Q	0.5 – 5.0	1.0	Bandwidth. Lower = wider, gentler; higher = surgical.
High-Mid Freq	500 Hz – 8 kHz	2.5 kHz	Presence and upper-mid control.
High-Mid Gain	±15 dB	0 dB	+2–4 dB at 2–4 kHz adds punch and intelligibility.
High-Mid Q	0.5 – 5.0	1.0	Bandwidth.
High Shelf Freq	2 – 20 kHz	10 kHz	Air and brightness center frequency.
High Shelf Gain	±15 dB	0 dB	API-style high shelf; +2–4 dB at 10–16 kHz adds sparkle.
Bypass	On/Off	Off	Bypasses the entire module with zero processing.

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Techniques

The API Smile Curve

The classic API console move that adds energy and excitement without increasing perceived loudness excessively:

Band	Setting
Low shelf	+3 dB @ 80 Hz
Low-mid	−2 dB @ 300–400 Hz
High shelf	+3 dB @ 10 kHz

The low-mid dip creates separation between bass and kick drum. The dual boosts flatter the frequency extremes without adding harshness.

Surgical Mud Removal

For dense mixes with low-mid buildup:

• Low-mid: −3 to −5 dB @ 200–350 Hz, Q 2.0–3.0
• Use Solo mode on Dynamic EQ Band 2 to identify the exact mud frequency first

Mix Bus Air

Adding openness to a dense mix without a Pultec:

• High shelf: +1.5 to +2.5 dB @ 12–16 kHz
• High-mid: +1 dB @ 5 kHz for presence

Gain Staging

Place API5500 first in the signal chain. Correcting tonal imbalances before compression means the compressor works on a more balanced signal and responds more musically.

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Signal Flow

Input → HPF → Low Shelf → Low-Mid Bell → High-Mid Bell → High Shelf → Output

See Also

• Techniques & Presets — API5500 EQ curve recipes
• Genre Signal Chains — how the API5500 is used per genre
• Instrument Buses — per-bus EQ starting points