[LAD] Open Source to be or not to be?

Fons Adriaensen fons at linuxaudio.org
Tue Jul 1 10:16:25 UTC 2014

On Tue, Jul 01, 2014 at 09:24:43AM +0200, hermann meyer wrote:

> As a example, we have the jcm800pre, a GCB95 and a baxandall tone
> control simulation as plugin in guitarix, generated with this
> toolkit.

Do you really believe that a Baxandall tone control is in any
way different from the combination of a standard first order
LF and an HF 'shelf' equaliser ? 

Well, it isn't, the two are mathematically equivalent.

The Baxandall circuit is just a very convenient way to realise such
filters in analog HW. Its main advantage is that it will provide
symmetrical (in dB) EQ curves having a decent control law, while
still using standard linear pots, and that it is fairly tolerant
of typical component errors. That's all there is to it, it doesn't
sound different from any first order shelf filter.

Any suggestion that the digital emulation of such a circuit would
be 'better' than standard digital filters is nonsense and pure
snake oil.

And you can't even model the circuit correctly in discrete time
as it requires a zero delay feedback path (as do many classic
analog circuits). Unless you pump up the sample rate to some
mad value.



A world of exhaustive, reliable metadata would be an utopia.
It's also a pipe-dream, founded on self-delusion, nerd hubris
and hysterically inflated market opportunities. (Cory Doctorow)

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