• Hardware-Measured Precision: All frequency bands, gain laws, and Q geometries were captured from physical console channels, matching original hardware filter curves within 0.44 dB RMS.
• Dual-Channel Tolerance Modeling: Accurately simulates the subtle electrical tolerances and channel-to-channel discrepancies between physical Left and Right desk modules, creating an authentic, three-dimensional stereo spread.
• Four Historical EQ Voicings: Instant switching between four distinct eras of console EQ:
  • Pink (G-Style): Proportional-Q design where bandwidth narrows as boost/cut increases, offering smooth, musical shelving and gentle midrange control.
  • Brown (Early E-Series): The original 02-design with broader bell curves and classic musical resonance.
  • Orange (Mid E-Series): Reworked low/high shelf curves for tighter punch and focused mid control.
  • Black (Late E-Series): Renowned 242-design featuring constant-Q bell characteristics, steeper high-pass filtering (18 dB/octave), and aggressive low-end punch.
• Dual Engine Architecture: Switch seamlessly between fully modeled Analog EQ Mode (including saturation, transformer load, and phase response) and pristine Digital EQ Mode.
• Pioneering Reference Calibration (Ref Cal): Decouples incoming track volume from analog stage drive, ensuring presets land at their intended harmonic sweet spot without touching the Input Trim knob.
• Preamplifier & Clipper Modeling: Features dedicated Mic/Line input stages, Drive, Impedance modeling, Analog Expansion, and selectable soft-clipping modes (Practical 0 dBFS vs. Accurate +30 dBu).
• Comprehensive Mid/Side Matrixing: Independent or linked M/S equalization for precision mastering and stereo-bus unmasking.

The Challenge in Modeled Analog Plugins:
Analog modeled circuits react dynamically to incoming signal levels. When a preset is engineered, the sound designer assumes the signal hits the modeled stage at the console's physical reference level (e.g., -18 dBFS = 0 VU / +4 dBu). If your incoming track is recorded quieter or hotter:

1. The circuit saturation and harmonic coloration designed into the preset will not react correctly.
2. The standard solution—adjusting the Input Trim—forces you to alter the primary knob meant to control how hard you drive the simulated analog circuits.

The Ref Cal & Auto Input Solution:

• AEQ-4000 solves this via Ref Cal (accessed as the third operational state of the Unity switch).
• Clicking Auto Input measures incoming signal levels and stores a background correction value directly inside the DSP engine without moving the physical Input Trim knob.
• The applied calibration offset is indicated directly on the button display.
• Because calibration is an internal calibration state rather than a standard DAW-automatable plugin parameter, it is never baked into or overwritten by preset loading.
• Exiting Ref Cal bypasses calibration without losing the calculated value; toggling back immediately restores the calibrated level without needing a re-measurement pass.

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NK PRODUCTIONS — AEQ-4000 FUSION EXTREME v1.3.1 CHANGELOG

[DSP & CORE]

• Optimizations for SSL E/G series curve modeling algorithms.
• Fixed phase alignment issues when combining High-Pass and Low-Pass filters simultaneously.
• Reduced overall CPU consumption during high oversampling modes (4x / 8x).

[INTERFACE & STABILITY]

• GUI scale rendering fixes on High-DPI and 4K displays.
• Fixed parameter automation stepping and state recall anomalies within VST3 hosts.
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1. Filter Section (HPF & LPF):

   • High-Pass Filter (HPF): 16 Hz to 350 Hz with steep 18 dB/oct attenuation.
   • Low-Pass Filter (LPF): 3 kHz to 22 kHz with gentle 12 dB/oct slope.
   • Realigned phase response prevents transient thinning when both filters overlap.

2. 4-Band Parametric Equalizer:

   • High Frequency (HF): 1.5 kHz to 16 kHz; switchable between shelving and bell curves.
   • High-Mid Frequency (HMF): 600 Hz to 7 kHz; continuously variable Q factor (0.5 to 2.5) with ±15 dB boost/cut and x1 / x3 multiplier switches.
   • Low-Mid Frequency (LMF): 200 Hz to 2.5 kHz; continuously variable Q with ±15 dB boost/cut and /1 / /3 divider switches.
   • Low Frequency (LF): 30 Hz to 450 Hz; switchable between bell and shelf curves.

3. Analog Preamp & Output Stage:

   • Input Stages: Selectable Mic In (higher harmonic saturation profile) or Line In (clean, high-headroom line driver).
   • Drive & Impedance: Adjusts nonlinear circuit compression and source resistance loading.
   • Analog Expansion: Widens the acoustic depth by exaggerating measured component tolerances between Left and Right channels.
   • Clip Mode: Choose between Practical (0 dBFS) for standard in-the-box limiting or Accurate (+30 dBu) for hardware-matched console headroom behavior.

• Plugin Format: VST3 Native (64-bit)
• Internal DSP Engine: 64-bit floating point with switchable real-time 2x, 4x, and 8x oversampling
• Sample Rate Support: 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz, 176.4 kHz, 192 kHz
• Channel Topologies: Mono, Stereo Interleaved, Mid/Side (M/S)

Compatible Digital Audio Workstations:

• Steinberg Cubase 11 / 12 / 13 / 14 & Nuendo
• Image-Line FL Studio 20 / 21 / 2026
• Ableton Live 11 / 12
• PreSonus Studio One
• Cockos REAPER
• Bitwig Studio
• Cakewalk by BandLab

Step-by-Step Installation:

1. System Preparation:

   • Close your DAW and any active VST3 host applications.

2. Install Plugin:

   • Run the provided installer executable (Setup.exe or equivalent) as Administrator.
   • Confirm your 64-bit VST3 directory (typically C:\Program Files\Common Files\VST3\).
   • Complete the installation sequence.

3. Activation via Keygen / Patch:

   • Launch the included Team R2R Keygen utility (NK_Productions_Keygen.exe) as Administrator.
   • Select AEQ-4000 Fusion eXtreme from the software list.
   • Generate and apply your license file (or follow the automated patching script if pre-cured).

4. Verify Installation:

   • Open your DAW, initiate a plugin rescan, and load AEQ-4000 onto an audio or bus track.
   • Confirm that the GUI renders smoothly at your native monitor scaling and all four EQ style modes switch without authorization prompts.