Z-Plane Filter

[The Chase]

Call me silly, but, erm, what exactly is a Z-Plane filter? And what makes a filter so Z-plane?

Cheers,
Chase

[mojogigolo]

it was invented by tattoo, the midget off paradise island.
[/i]

[androidlove]

it was invented by tattoo, the midget off paradise island.
http://www.tv1.com.au/content/shows/cut ... island.jpg

[lawapa]

Think E-MU. That is their filter, and it set there sampler keyboards apart from the rest. Since this was always assochiated with there hardware I think it's has no software emu-lation? The structure and how it functions though is not known to me.

[meister eder]

Call me silly, but, erm, what exactly is a Z-Plane filter? And what makes a filter so Z-plane?

Think of it like a cube, where all 8 corners of the cube have their own filter model. Kind of like a vector pad, but 3-dimensional.
Now you can morph between those 8 filter models: The X axis being controlled by the note number, the Y axis being controlled by velocity, and the Z axis being controlled by a controller of your choice. Hence the name Z-plane.

[munchkin]

It's a morphing filter capable of changing settings over time for creating changes in very complex sounds. It's available in the synths that come bundled with some of E-mu's soundcards.

I think I'll just stick with the presets rather than twiddling the z-plane's.

[TechnoWeeniePas]

If you want to read from EMU download the ESI-4000 sampler manual (I know its in there because thats the sampler I own). Check out Chapter9 page 7.
In short a Z filter controlably morphs multiple filters.

[tomg]

From the e-mu manual...

The Z-plane filter has the ability to change its function over time.

Consider, as an example, the human vocal tract, which is a type of complex filter or
resonator. There are dozens of different muscles controlling the shape of the vocal tract.
When speaking, however, we don't think of the muscles, we just remember how it feels
to form the vowels. A vowel is really a configuration of many muscles, but we consider it
a single object. In changing from one vowel to another, we don't need to consider the
frequencies of the resonant peaks! You remember the shape of your mouth for each
sound and interpolate between them. This is similar to what the Z-plane filter does.

Sweetwater Glossary - Z-Plane Synthesis

http://www.sweetwater.com/expert-center ... eSynthesis

[The Chase]

Interesting. I often will make complex filters with the FL Studio parametric EQ by making one band an LP and another band an HP filter and linking the cutoff frequencies for both to the same controller knob. SOmetimes I throw a BP or 2 in there. Is it possible to create a Z-Plane filter this way?

[> DiGiT <]

isnt every filter a z-plane filter in that theres frequency, amplitude, and time? the time dimension is the z-plane, and indeed morphs from one setting to another.

[meister eder]

I think I'll just stick with the presets rather than twiddling the z-plane's.

Just start with assigning different envelopes or LFOs to the Z axis of the filter. It's fun to twiddle!

[meister eder]

isnt every filter a z-plane filter in that theres frequency, amplitude, and time? the time dimension is the z-plane, and indeed morphs from one setting to another.

It's not settings of one filter that are being morphed, it's actually different filter models being morphed. In the most simple case that would be e.g. morphing between a 24db LP, a 12db HP, Notch filter, another 48db LP, ..... you get the idea. Now the numerous models that the Z plane filters offer are much more complex, from simple filters to equalizers to vowel and formant filters to phasers, etc.

[Shane Sanders]

Interesting. I often will make complex filters with the FL Studio parametric EQ by making one band an LP and another band an HP filter and linking the cutoff frequencies for both to the same controller knob. SOmetimes I throw a BP or 2 in there. Is it possible to create a Z-Plane filter this way?

I don't think it is unless you have those filters linked by a more complex system. What you've describe sounds like more of a static effect approach, though you may have each thing with some automation.

I think the key to a z-plane type filter set is to associate various playable variables such as velocity or aftertouch with them. Then, and this is the most important part, arrange it so that once those variables are in play, have them subsequently morph over time in a smooth way. Sounds more impressive verbally than it does aurally, imo, though one might occasionally make something worthy of the time involved in trying to develop it. Most musical sounds are fairly short and have their own properties that humans find interesting already. So making a bell sound crawl between a low-pass state to something else while in the presence of other sounds may end up not being all that impressive because small details sometimes die once sounds are together in a mix.

This is probably why orchestration is a separate discipline from composition, albeit symbiotic with it.

[androidlove]

mr green
http://www.kvraudio.com/get/1607.html

[Barbed Wire Kiss]

How close is Filterscape to E-mu's Z-Planes? With the combination of the variable state filter and the morphing EQ this has always appeared the nearest in vst-land.