HighPassFilter

A high-pass audio filter that attenuates frequencies below a cutoff point.

High-pass filters allow high frequencies to pass through while reducing or eliminating low frequencies. Common uses include:

• Removing rumble or low-frequency noise
• Creating "tinny" or "telephone" effects
• Frequency band isolation for audio analysis
• Cleaning up muddy audio mixes

The filter uses a biquad implementation for stable, efficient processing with adjustable resonance (Q factor) for frequency emphasis at the cutoff.

// Remove low frequencies below 200Hz
var highPass = new HighPassFilter();
highPass.cutoffFrequency = 200;
highPass.gain = 1.0;

// Create a resonant high-pass effect
var resonantHP = new HighPassFilter();
resonantHP.cutoffFrequency = 1000;
resonantHP.resonance = 5.0;  // Emphasize the cutoff frequency

// Apply to an audio mixer
audioMixer.addFilter(highPass);

Instance Members #

Cutoff frequency in Hz. Frequencies below this value will be attenuated. Range: 1 Hz to half the sample rate (Nyquist frequency). Default: 1000 Hz

Filter gain/amplitude multiplier. Adjusts the overall output level after filtering. Range: 0.0 to any positive value (1.0 = unity gain). Default: 1.0

Filter resonance/Q factor. Controls the sharpness of the filter and frequency emphasis at the cutoff.

• 0.707: No resonance (Butterworth response)
• < 0.707: Gentler rolloff
• > 0.707: Sharper rolloff with peak at cutoff Range: 0.1 to 30.0 (higher values = more resonance) Default: 0.707

Metadata #