Overview
Multi-channel envelope detector with programmable attack and release times
Discussion
This subsystem implements N-way crossover filters of either Linkwitz-Riley or Butterworth design. Internally, the crossovers are constructed out of two other subsystems: a 1in-2out crossover which divides the input into two separate frequency bands and an allpass phase compensation network. The 1in-2out crossover consists of lowpass (first output) and highpass (second output) filters. The lowpass and highpass filters are designed such that the sum of their responses equals an allpass filter with unity gain - and this allpass response equals the response of the allphase phase compensation network. An N-way crossover is constructed by cascading these subsystems.
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In the Butterworth filter design, the lowpass and highpass filters are each standard Butterworth designs and the order must be odd. The odd order requirement ensures that the sum of the splitting filters is an allpass, and the allpass compensation filter equals the the sum of the splitting filters. The order of the allpass compensation filter matches the order of the splitting filters. Thus, 5th order splitting filters require a 5th order allpass network
Type Definition
-Not Shown-
Variables
Properties
Name | Type | Usage | isHidden | Default value | Range | Units |
cutoff | float* | parameter | 0 | [1 x 1] | 1:23997.6 | Hz |
N | int | const | 0 | 2 | Unrestricted |
Pins
Input Pins
Name: in
Description: audio input
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Sample rate range: Unrestricted
Complex support: Real
Output Pins
Name: out1
Description: Audio output
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Description: Audio output
Data type: float
Scratch Pins
Channel count: 1
Block size: 32
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Block size: 32
Sample rate: 48000
MATLAB Usage
File Name: xover_nway_subsystem.m
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