Hello forum 
my plan is to apply parallel bandpass filters on an input signal using an array of ProcessorDuplicators. I’m getting an assertion failure in juce_ProcessorDuplicator.h:70:
jassert ((int) context.getInputBlock().getNumChannels() <= processors.size());
I have no idea what could be wrong with my code or how to set the number of processors correctly. Do you?
PluginProcessor.h:
AudioBuffer<float> audioAnalyseBuffer;
static const int filterCount = 22;
array<dsp::ProcessorDuplicator<dsp::IIR::Filter<float>, dsp::IIR::Coefficients<float>>, filterCount> modulatorFilterBank;
PluginProcessor.cpp:
prepareToPlay (double sampleRate, int samplesPerBlock)
{
audioAnalyseBuffer.setSize(getTotalNumInputChannels(), samplesPerBlock);
dsp::ProcessSpec spec;
spec.sampleRate = sampleRate;
spec.maximumBlockSize = samplesPerBlock;
spec.numChannels = getTotalNumOutputChannels();
for (int i = 0; i < modulatorFilterBank.size(); ++i) {
modulatorFilterBank[i].reset();
*modulatorFilterBank[i].state = *dsp::IIR::Coefficients<float>::makeBandPass(sampleRate, frequency, filterQ);
modulatorFilterBank[i].prepare(spec);
}
}
processBlock (AudioBuffer<float>& buffer, MidiBuffer& midiMessages)
{
dsp::AudioBlock<float> audioInputBlock(buffer);
dsp::AudioBlock<float> audioAnalyseBlock(audioAnalyseBuffer);
for (int i = 0; modulatorFilterBank.size(); ++i) {
// this is what causes the assertion failure:
modulatorFilterBank[i].process(dsp::ProcessContextNonReplacing<float>(audioInputBlock, audioAnalyseBlock));
}
}
I’ve tried replacing all the numChannels methods with a fixed value of 2, didn’t help.
Also I’ve std::cout << processor.size() right before the jassert. It prints 44 times 2, then once 0, followed by the assertion failure.
when I used dsp::StateVariableFilter before, it worked with my approach.
Do you have any hints or ideas what might be wrong?
Thanks a lot 
