[LAU] M/S EQ in Linux

Fons Adriaensen fons at linuxaudio.org
Tue Sep 10 22:21:29 UTC 2013

On Tue, Sep 10, 2013 at 02:43:37PM -0700, J. Liles wrote:

> BTW upon further review, I think the Multiband EQ from SWH LADSPA plugin
> suite is linear phase--you'd only have to watch out for the latency it
> introduces (which wouldn't be a problem if you used an instance each for M
> and S).

There is really no reason at all to think that linear phase EQ
would provide any advantage or be required. Almost all physical
processes that modify a frequency response (e.g. resonances) 
are minimum-phase, not linear phase. The minimum phase response
is in a sense 'natural', it's the one that requires the least
internal state and it can be the result of a very simple physical

This is the reason why sounds that have a fast attack and an
exponential decay (a 'ping', min-phase) occur much more easily
that those that do the inverse (a 'gnip', max-phase) or have 
a symmetrical envelope ('gnipping', linear phase).



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)

More information about the Linux-audio-user mailing list