Emu XL-7 & MP-7 User's Group

During a given note's lifespan, yes, there is one tweakable parameter, usually tied to Fc.  That said, every new note can have a completely different set of filter coefficients.  There are plenty of ways around this, though, the easiest being putting different filters on different layers...

-Æ


----- Original Message ----
From: Atom Smasher <atom@...>
To: xl7@yahoogroups.com
Sent: Sunday, January 11, 2009 5:02:35 PM
Subject: Re: [xl7] Re: z-plane - is it "all that"?

so... the way it's implemented on the command stations, it comes down to 
_one_ dynamic (aka: tweakable) parameter: filter cutoff. and instead of 
being able to set our own filter types/parameters at either end of the 
knob, each filter in the drop-down list is built around one or two types 
of filters hard-coded at the factory...? and the way some of the filter 
models are designed we can expect results that are very different from a 
traditional VFC as we turn the "cuttoff" knob...?

did any of the emu synths implement it as described as lines, squares & 
cubes with arbitrary (user configurable) filters at the corners? or are 
they all implemented like the command stations?


On Sun, 11 Jan 2009, Aaron Eppolito wrote:

> That said, there *is* a grain of truth to the whole "Z = morphing" 
> misconception.  By modeling your entire filter as individual poles and 
> zeros, you could modify each pole or zero individually, letting you 
> dynamically alter a filter into a completely different kind of filter. 
> The filter chip in the E-mu products has one hardware interpolator, 
> allowing it to go from one set of filter coefficients to another in 
> hardware..  This also means that it only has one hardware degree of 
> freedom (hence the only dynamic parameter being Fc).  To do other 
> realtime manipulations, the software has to load a whole other set of 
> coefficients, then use the hardware to switch to them smoothly.  This 
> takes a lot of CPU, and can sound choppy if not updated frequently 
> enough.  It is, however, really really cool when it sounds right.