Back to Home

Professional EQ Demo

Accurate parametric EQ with mathematical frequency response

About Professional Parametric EQ

A parametric equalizer provides precise frequency shaping using mathematical biquad filters. This demo implements accurate filter calculations, Q factor bandwidth relationships, logarithmic frequency scaling, and real-time transfer function visualization.

Mathematical Parameters:

  • Frequency: Center frequency of the bell filter (Hz)
  • Gain: Boost/cut amount at center frequency (±15dB)
  • Q Factor: Filter selectivity - Q = f₀/BW
  • Bandwidth: Width of affected frequencies (Hz)
  • Biquad Coefficients: Digital filter implementation
  • Logarithmic Scaling: Perceptually accurate frequency display

Implementation Features:

  • Accurate bell filter frequency response calculations
  • Real-time biquad coefficient computation
  • Professional RTA with 4.5dB/oct analyzer slope
  • Logarithmic frequency axis (20Hz-20kHz)
  • Interactive frequency response curve
  • Q factor bandwidth visualization

Professional Parametric EQ Plugin Interface

Input Spectrum

20Hz20kHz
Pink Noise Reference
Pink noise reference
4.5dB/oct analyzer slope

4-BAND PARAMETRIC EQ

0 Active | Ref: 0.0dB @ 1kHz
Band 1
200 Hz
0 dB
1.5
Band 2
1000 Hz
0 dB
1.5
Band 3
5000 Hz
0 dB
1.5
Band 4
10000 Hz
0 dB
1.5

Output Spectrum

20Hz20kHz
EQ Applied
EQ response applied
0 bands active

Mathematical Frequency Response

Frequency (Hz)Gain (dB)
Real-time biquad filter response calculation
Active bands: None

Professional Implementation Notes

Q Factor Relationships

Q = f₀/BW. High Q (>5) for surgical cuts, medium Q (1-3) for musical shaping, low Q (0.5-1) for broad tonal changes. Q affects bandwidth logarithmically.

Frequency Targeting

Sub: 20-60Hz, Bass: 60-250Hz, Low-Mid: 250-500Hz, Mid: 500-2kHz, Upper-Mid: 2-5kHz, Presence: 5-8kHz, Brilliance: 8-20kHz.

Mathematical Precision

Biquad filters provide exact frequency response. Use RTA to visualize cumulative effect. Each 6dB boost doubles perceived loudness at that frequency.