[PD] [biquad~] as cyclone's [allpass~]?

[Chris Clepper]

You only need one delay line for the allpass.

feedforward = input * -gain
feedback = delayout * gain
delayin = input + feedback
output = delayout + feedforward

http://www.spinsemi.com/knowledge_base/effects.html#Reverberation


On Thu, Oct 3, 2013 at 11:29 AM, Alexandre Torres Porres
<porres at gmail.com>wrote:

> i hope i guess i figured it out on how to implement it with delay lines.
> see attachment. And I realize you can't do this with [fexpr~] or [biquad~]
> because the sample delay length is kinda big for that, right?
>
> cheers
>
>
> 2013/10/3 Alexandre Torres Porres <porres at gmail.com>
>
>> cool, but do you know how to implement cyclone's [allpass~] with it?
>>
>> It's really unclear to me what is the relation of this pass filter with
>> the one you can generate with biquad coefficients, or with raw poles/zeros
>> objects for that matter.
>>
>> Well, one way or another, it's also unclear to me how to do it with delay
>> lines.
>>
>> seems that it is related to a comb filter, right?
>>
>> cheers
>>
>>
>> 2013/10/2 Chris Clepper <cgclepper at gmail.com>
>>
>>> Allpass for reverb is easy to do with delwrite~ and vd~.  I used 32 of
>>> them today to recreate a famous 'deep space' reverb.
>>>
>>>
>>> On Wed, Oct 2, 2013 at 1:53 AM, Alexandre Torres Porres <
>>> porres at gmail.com> wrote:
>>>
>>>> hi there, i see the biquad's coefficients can be set as an allpass
>>>> filter, generated by frequency and "Q" parameters. But can it do the same
>>>> as cyclone's [allpass~] filer? If yes, them how since the parameters for
>>>> [allpass~] are different (delaytime and such).
>>>>
>>>> One way or another, I guess that my real question is: how to implement
>>>> [allpass~] from vanilla objects?
>>>>
>>>> thanks
>>>>
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>>>
>>
>
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