[PD] pd book sprint
Derek Holzer
derek at umatic.nl
Mon Mar 30 17:45:44 CEST 2009
Could you post the adjusted patches, I'd like to see where your
corrections are before I agree to change stuff that is already there.
best!
D.
Alexandre Porres wrote:
> Hi D.
>
> Yeah, DC Offset could be covered in what is digital Audio, or maybe
> briefly mentioned. The thing is that it needs patches to explain and
> show how adjusting the DC Offset works.
>
> I know things must be kept as simple as possible, but not simpler than
> that, because it could be misleading. I had that problem myself when
> teaching with Floss Manuals, students had doubts why the square and
> sawtooth oscilators were different, or "wrong".
>
> The DC Offset is an extremely important parameter that should be a part
> of the synthesizer section of Floss Manuals. It could also be a part of
> the Amplitude Modulation Examples. Actually, changing DC Offset is all
> it needs to change from an Amplitude Modulation to a Ring Modulation. So
> having a DC Offset parameter there can explain the differences between
> the two.
>
> For instance, I find the osc7.pd example really misleading. At first, it
> is supposed to be a Ring Modulation instead of an Amplitude Modulation,
> since there is no DC offset in the modulator sigal. But, as the sawtooth
> wave oscilator has a DC Offset (that shouldnt be tghere anyway, and it
> is not even mentioned), it is actually an Amplitude modulation after
> all, with the Remark that the Carrier signal has the role of the
> Modulator signal, and Not the carrier signal itself. So, in any way
> (either presenting it as a Ring Modulation or Amplitude Modulation)
> corrections should be made.
>
> So I dont see a way of not editing these patches, because it could be
> even more confusing if we would write a disconected chapter that
> complements and gives the tools to correct things that could have been
> presented before.
>
> I just don't see how simplicity here compensates the misleading way the
> theory is presented.
>
> The DC Offset is the main problem I see in Floss Manuals. And I actually
> give my students an altered version of Floss Manuals to work with
> because of that. I am developing a book of my own that complements well
> with the Floss Manuals, but I still need to do make this Remark.
>
> I could show my book, but it is in Portuguese only, so far...
>
> by the way, we have people in Brazil who would like to collaborate and
> translate this to portuguese.
>
> I can send you a triangle wave oscilator right away.
>
> cheers
> alex
>
>
> On Mon, Mar 30, 2009 at 11:56 AM, Derek Holzer <derek at umatic.nl
> <mailto:derek at umatic.nl>> wrote:
>
> Actually, DC offset could be covered in "What is Digital Audio",
> since it is a concept that needs explaining. Then, my suggestion
> still is to include it after the basics of the Square Waves. I'd
> like to keep the patches there as simple as possible, and since the
> DC Offset can be done at the end, why not have it there?
>
> Triangle wave would also be good. Write it first and we'll see where
> exactly to put it.
>
> D.
>
>
> Alexandre Porres wrote:
>
> sure, I could do both.
>
> But I think it would be inportant to start just after
>
> * AUDIO TUTORIALS
> * SimpleSynthIntroduction
> <http://en.flossmanuals.net/PureData/SimpleSynthIntroduction>
>
>
>
> and before the oscilators with the Short DC offset chapter.
>
> Then edit and correct the oscilator patches with values from -1 to 1
>
> I also can create and put in the oscilator chapter a Triangle
> wave oscilator made with phasor
>
> what do you say?
>
> Cheers
>
>
> On Mon, Mar 30, 2009 at 11:43 AM, Derek Holzer <derek at umatic.nl
> <mailto:derek at umatic.nl> <mailto:derek at umatic.nl
> <mailto:derek at umatic.nl>>> wrote:
>
> Alexandre,
>
> Yes please, get on board!
>
> In the case of the square wave chapter, I had assumed that
> doing it
> with digital logic would result in either 0 (no amplitude) or 1
> (full amplitude). So there shouldn't be any DC offset when
> it's at
> 0. Of course, there are some other real-world problems with those
> patches, namely that there is also no antialiasing.
>
> Since the FLOSS Manuals are "modular", they can be remixed as
> needed
> for any kind of workshop, class or curriculum, including or
> leaving
> out sections from all the different FLOSS Manuals as needed.
>
> So my suggestion to you would be to write a short chapter on DC
> offset which can then be referred to in the square wave
> tutorial, or
> in any other tutorial or manual where such a situation might
> arise.
>
> Likewise, I'd love it if someone could do a single chapter on the
> different antialiasing methods (Miller's, Frank's...). The idea
> would be to simplify the explanations so that one doesn't need a
> background in DSP or computer science in order to understand
> them.
>
> Would you be interested to do either of those?
>
> D.
>
> Alexandre Porres wrote:
>
> Hi, I am really interested in helping!
>
> I actually have some stuff I wanted to "corrrect", or
> bring some
> attention to, like the DC OFFSET. You dont cover it, and when
> you show how to get a Square Wave, the DC Offset is not
> properly
> adjusted.
>
> thanks
>
> cheers
>
> On Mon, Mar 30, 2009 at 11:20 AM, Derek Holzer
> <derek at umatic.nl <mailto:derek at umatic.nl>
> <mailto:derek at umatic.nl <mailto:derek at umatic.nl>>
> <mailto:derek at umatic.nl <mailto:derek at umatic.nl>
>
> <mailto:derek at umatic.nl <mailto:derek at umatic.nl>>>> wrote:
>
> Hey Alexandre,
>
> I just posted the announcement of the Pd FLOSS Manuals
> Book
> Sprint:
>
>
> http://lists.puredata.info/pipermail/pd-list/2009-03/069107.html
>
> I was wondering if you'd be interested to help out next
> weekend? It
> shouldn't be a problem to contribute remotely, and it
> would
> really help
> build up the momentum to finish this manual.
>
> Have a look over the topics and see if there is anything
> you'd like to
> cover and let me know.
>
> Best!
> Derek
>
> -- ::: derek holzer :::
> http://blog.myspace.com/macumbista :::
> http://www.vimeo.com/macumbista :::
> ---Oblique Strategy # 11:
> "Always first steps"
>
>
>
>
>
> -- Alexandre Torres Porres
> cel. (11)8179-6226
> Website: http://porres.googlepages.com/home
> http://www.myspace.com/alexandretorresporres
>
>
> -- ::: derek holzer ::: http://blog.myspace.com/macumbista :::
> http://www.vimeo.com/macumbista :::
> ---Oblique Strategy # 109:
> "Lost in useless territory"
>
>
>
>
> --
> Alexandre Torres Porres
> cel. (11)8179-6226
> Website: http://porres.googlepages.com/home
> http://www.myspace.com/alexandretorresporres
>
>
> --
> ::: derek holzer ::: http://blog.myspace.com/macumbista :::
> http://www.vimeo.com/macumbista :::
> ---Oblique Strategy # 67:
> "Emphasize the flaws"
>
>
>
>
> --
> Alexandre Torres Porres
> cel. (11)8179-6226
> Website: http://porres.googlepages.com/home
> http://www.myspace.com/alexandretorresporres
>
--
::: derek holzer ::: http://blog.myspace.com/macumbista :::
http://www.vimeo.com/macumbista :::
---Oblique Strategy # 110:
"Lowest common denominator"
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