[LAU] Pro Audio? OT rant.

[Monty Montgomery]

On Sun, Dec 23, 2012 at 10:06 PM, Chris Bannister
<cbannister at slingshot.co.nz> wrote:

> So artifacts (transient peaks) on the trailing or leading edges of a
> square wave is not a form of ringing?

In this case, yes.  They're a fundamental aspect of any bandlimited
signal and you'll see them even when the filters are all FIR.  You can
see also them on any scope-- so long as the scope has a greater
bandwidth than the squarewave you're inspecting (perfect squarewaves
require infinite frequencies, and so do not actually exist).

And, like I said, you can massage the frequency response of a filter
to hide the ripples and overshoots by spreading the Gibbs effect over
a wider spectral area, giving the illusion that they're not there when
you look at it on a scope.  That's mostly a trick of presentation.
Your ear doesn't care (though your circuits might, if you're trying to
limit the analog signal range).

You could also have a filter that really is adding ringing, but that's
something different.

Monty