[LAU] Exciter / Enhancer Plugin [WAS:] Linux-audio-user?Digest , Vol 19, Issue 9

Reuben Martin reuben.m at gmail.com
Fri Sep 12 13:21:43 EDT 2008


Back on Friday 12 September 2008, Fons Adriaensen was like:
> On Thu, Sep 11, 2008 at 10:45:35PM -0500, Reuben Martin wrote:

> > The magnitude can be positive or negative. It really doesn't matter which
> > way you go, you get a similar effect.
>
> Positive or negatve *at what point* ?
> Start gnuplot and type
>
> plot [0:6.28] sin(x), sin(3*x)
>
> At 0, both are going positive. At 1.57 one is positive and
> the other negative.  If you invert the second, they will
> be 'in phase' at 1.57.

I'm talking in reference to the ladspa harmonics generator plugin.


>
> Simple fact is that you can't compare phases of two signals
> that don't have the same frequency. It just depends on where
> you look.
>
> > But each successive odd harmonic needs to
> > be in the opposite direction in order for them to build upon one another.
> > Otherwise they begin to cancel each other out.
>
> Signals of different frequencies cam't ever cancel each other.

No, but they can seriously mangle one another in an undesirable manner. If 
successive odd harmonics are given the same positive or negative magnitude in 
the harmonics generator plugin, the exciter effect is more muted and sounds 
muffled, whereas if they are pushed in opposite directions of magnitude, each 
odd harmonic intensifies the effect of the odd harmonic before it.

>
> So what does all this mean ?

It means that if you run the third and fifth harmonic magnitude both in the 
positive or negative direction on the jack rack setup I provided, it's 
probably going to sound like poo.

-Reuben








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