Cycling 74 » Topic: Equivalents http://cycling74.com/forums/topic/equivalents/feed Wed, 19 Jun 2013 16:08:14 +0000 http://bbpress.org/?v=2.2.4 http://cycling74.com/forums/topic/equivalents/#post-45267 <![CDATA[Equivalents]]> http://cycling74.com/forums/topic/equivalents/#post-45267 Sat, 29 Aug 2009 13:34:16 +0000 Cripto Hello there!
Just a simple question… Does anybody knows which are the
objects as the Pure Data’s rpole~ and rzero~ in max/MSP??
Thank u very much! Smile

]]> http://cycling74.com/forums/topic/equivalents/#post-163120 <![CDATA[Re: Equivalents]]> http://cycling74.com/forums/topic/equivalents/#post-163120 Tue, 11 Jan 2011 01:29:47 +0000 Holland Hopson I’m having fun working through Andy Farnell’s “Designing Sound” book and have run into this as well. Farnell writes about using rzero~ for “differentiation” – the opposite of integrating a signal. I’ve gotten similar results using a hipass filter at 0.999 Hz. Is there a more exact equivalent for rzero~?

The pd help file says this about rzero~:
“rzero~ real one-zero (non-recursive) filter, raw

Rzero~ filters an audio signal (left inlet) via a one-zero real filter, whose coefficient is controlled by a creation argument or by an audio signal (right inlet).

The action of rzero~ is: y[n] = x[n] – a[n] * x[n-1]
where y[n] is the output, x[n] the input, and a[n] the filter coefficient. The filter is always stable.
The transfer function is H(Z) = 1 – aZ^-1.”

]]> http://cycling74.com/forums/topic/equivalents/#post-163121 <![CDATA[Re: Equivalents]]> http://cycling74.com/forums/topic/equivalents/#post-163121 Thu, 27 Jan 2011 17:00:13 +0000 Holland Hopson Here’s an rzero~ abstraction based on the filter equation given in the PD help patch. Seems to work fine. rpole~ can’t be built as an abstraction since it’s a recursive filter. I tried wrapping it in a poly~ set to vs 1, but it didn’t work properly.

– Pasted Max Patch, click to expand. –
]]> http://cycling74.com/forums/topic/equivalents/#post-163122 <![CDATA[Re: Equivalents]]> http://cycling74.com/forums/topic/equivalents/#post-163122 Thu, 27 Jan 2011 22:14:19 +0000 stefantiedje rpole~ can be build as an abstraction, as its a special case of a biquad~ ( which is rzero~as well btw):

– Pasted Max Patch, click to expand. –
]]> http://cycling74.com/forums/topic/equivalents/#post-163123 <![CDATA[Re: Equivalents]]> http://cycling74.com/forums/topic/equivalents/#post-163123 Sun, 06 Feb 2011 21:00:13 +0000 Holland Hopson Very helpful! biquad~ is the way to go. It’s been a good exercise for me to build these filters from the ground up (with delay~, +~, etc.). Now it makes perfect sense to me how zeroing a1, a2 and b2 causes biquad~ to function as a single pole filter. Thanks!

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