Cascaded Allpass Filter Test Bed
L
R
-∞ dB
Order
Frequency
(Hz)
(Hz)
Feedback
(g)
(g)
Resonance
(Q)
(Q)
Cascade
Stages
Stages
Frequency
Spread
Spread
Spread
Pattern
Pattern
LFO
Depth (Hz)
Depth (Hz)
LFO
Rate (Hz)
Rate (Hz)
LFO
Wave
Wave
Stereo
Offset (Hz)
Offset (Hz)
Dry/Wet
Mix (%)
Mix (%)
Input Gain
(dB)
(dB)
Output Gain
(dB)
(dB)
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Cascaded Allpass Filter Test Bed
Order: Select the order of each allpass stage (1st through 128th order = 6-768 dB/octave)
Frequency: Base frequency for the allpass filter(s) (logarithmic scale)
Feedback (g): Coefficient for 1st order allpass delays (0.0-0.9)
Resonance (Q): Q factor for 2nd order and higher (0.707 = Butterworth)
Cascade Stages: Number of allpass filters in series (1-128)
Frequency Spread: Multiplier range for stage frequencies (1-10x)
Spread Pattern: How frequencies are distributed across stages
LFO Depth: Frequency modulation range in Hz (20-10000 Hz)
LFO Rate: Speed of modulation (0.01-100 Hz, logarithmic)
LFO Wave: Waveform shape for modulation
Stereo Offset: Frequency offset in Hz for right channel (0 = mono, higher values = wider stereo)
Dry/Wet: Mix between original and processed signal
Input/Output Gain: Level control in decibels
Downsample: Reduce sample rate for lo-fi effects (1x=normal, 2x=half rate, 4x=quarter rate) – affects wet signal only
Clipper: Soft clipping algorithms to prevent blowups (tanh, atan, soft, hard, cubic, sine, exponential, fuzz)
DC Filter: 100Hz highpass filter at 48dB/oct to remove DC offset
Allpass filters maintain unity gain while shifting phase. Cascading multiple stages creates complex phase relationships useful for diffusion and spatial effects.
Order: Select the order of each allpass stage (1st through 128th order = 6-768 dB/octave)
Frequency: Base frequency for the allpass filter(s) (logarithmic scale)
Feedback (g): Coefficient for 1st order allpass delays (0.0-0.9)
Resonance (Q): Q factor for 2nd order and higher (0.707 = Butterworth)
Cascade Stages: Number of allpass filters in series (1-128)
Frequency Spread: Multiplier range for stage frequencies (1-10x)
Spread Pattern: How frequencies are distributed across stages
LFO Depth: Frequency modulation range in Hz (20-10000 Hz)
LFO Rate: Speed of modulation (0.01-100 Hz, logarithmic)
LFO Wave: Waveform shape for modulation
Stereo Offset: Frequency offset in Hz for right channel (0 = mono, higher values = wider stereo)
Dry/Wet: Mix between original and processed signal
Input/Output Gain: Level control in decibels
Downsample: Reduce sample rate for lo-fi effects (1x=normal, 2x=half rate, 4x=quarter rate) – affects wet signal only
Clipper: Soft clipping algorithms to prevent blowups (tanh, atan, soft, hard, cubic, sine, exponential, fuzz)
DC Filter: 100Hz highpass filter at 48dB/oct to remove DC offset
Allpass filters maintain unity gain while shifting phase. Cascading multiple stages creates complex phase relationships useful for diffusion and spatial effects.