[sdiy] saw vs ramp, audible?

[Tom Wiltshire]

> On 19 Dec 2024, at 22:06, Mattias Rickardsson <mr at analogue.org> wrote:
> 
> On Thu, 19 Dec 2024 at 10:35, Richie Burnett <rburnett at richieburnett.co.uk <mailto:rburnett at richieburnett.co.uk>> wrote:
> MR wrote:
> 
> > ....But the triangle becomes a nice
> > almost-half-circular waveform if you align them!
> 
> It looks pretty much like a sinewave, but still has all the harmonics and 
> the timbre of a triangle.  That's pretty cool.  Another example of 
> substantially different looking waveforms with the same sound.  Also goes to 
> show that what initially *looks* like a decent sinewave can actually have 
> quite high distortion!
> 
> Oh no, they don't look much like a sinewave. It's more like a row of semi-circles upwards/downwards from the zero line. We use to call this waveshape "designers sinewave", since it's so often seen in illustrations of sinewaves, but totally wrong and in best case a misunderstanding of how sinewaves relate to circles. :-D
> 
> https://www.desmos.com/calculator/vtai9amxtl <https://www.desmos.com/calculator/vtai9amxtl>
> 
> What's interesting (and a bit annoying) is how it's not a perfect semi-circle but very very close... why would math bother with getting so close to a shape but not really mean it?

It could only be a perfect semicircle if the amplitude and the period happened to coincide anyway. You can set it up nicely, but as soon as you change the volume or frequency, the illusion is shattered!

I did some experiments with this shape since it's easy to generate the wave data to produce such a thing, and it's a pretty obvious next step after "Square" and "Triangle" waveforms.


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20241219/1f23da60/attachment.htm>