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

[Reuben Martin]

Back on Monday 22 September 2008, Fons Adriaensen was like:
> On Fri, Sep 12, 2008 at 06:17:38PM -0500, Reuben Martin wrote:
> > If you are truly that into the math side of it, the source for those
> > plugins is always available for you to pull apart and see for yourself
> > the innerworkings and algorithms used.
>
> I did some measurements on a real (hardware) Aural Exciter.
> Whatever it does is *very* different from what the harmonic
> generator plugin is doing.
>
> - Almost all harmonics up to at least the 15th are present.
>   The first few (2,3,4) have almost the same level, above
>   that levels go down gradually, with a clear dip at the
>   seventh.
>
> - The relative (to the fundamental) level of the harmonics
>   stays more or less the same for a wide range of input
>   levels. This is very different from any simple form of
>   harmonic generator, where the level of the Nth harmonic
>   would be roughly proportional to the Nth power of the
>   input level.


I have an Aphex 104 myself, and have been curious in how it works. My hack 
using the simple harmonics generator sounds nowhere near as smooth. It 
generally does "ok" for live recorded audio, but it doesn't sound very smooth 
on snyth generated sources. And it is nowhere near what I get with the Aphex 
unit.

I find it odd that the harmonics levels stay at the same level reguardless of 
the input level. Very interesting.

-Reuben