Filterscape & Z-Plane?

[Dave Bourke]

In another gear forum, I recently read a post stating that Filterscape offers the equivalent to the Z-Plane functionality of the E-mu filters found in their legacy EIV range of samplers and in the Morpheus.

Can someone please comment on this?

Kind regards.

[Urs]

The Z-Plane architecture is basically a normal filter topology (lowpass/highpass/bandpass/notch) with some peaking eq bands added in. That's how they do those formant-type sweeps.

Back in the days this was resolved with some tricks to tame the maths. It unfortunately meant that each 14-pole filter had only 2 degrees of freedom (or was it 3?), such as cutoff and resonance. Or cutoff and vowel. So they shipped their stuff with a gazillion of presets for various filter sweeps.

Nowadays all it takes is adding in a parameteric eq with 3-5 bands into a normal oscillator-filter-amplifier structure. And that's exactly what FilterscapeVA does. Only, in Filterscape you have loads of degrees of freedom because you can modulate any parameter of each band separately. Hence FilterscapeVA is you easy to use "DIY Z-Plane box".

Urs

[billstei]

So is it reasonable to assume that FilterscapeVA can do some formanty sounds without too much trouble?

[MitchK1989]

So is it reasonable to assume that FilterscapeVA can do some formanty sounds without too much trouble?

You do have to work out where to place the frequencies to get each formant, but then morphing between them is easy by saving each to a snapshot. It's not as immediate as a dedicated vowel filter where you can tell it to sweep between "E" and "O" or whatever, but it's FAR more flexible.

[jupiter8]

Here's some info on frequencies i found. You'll need at least 3 frequencies but all 5 are prefered. The filters should be in paralell.

Soprano 'a' f1 f2 f3 f4 f5
frequency (Hz) 800 1150 2900 3900 4950
Amp (dB) 0 -6 -32 -20 -50
bw (Hz) 80 90 120 130 140

Soprano 'e' f1 f2 f3 f4 f5
frequency (Hz) 350 2000 2800 3600 4950
Amp (dB) 0 -20 -15 -40 -56
bw (Hz) 60 100 120 150 200

Soprano 'i' f1 f2 f3 f4 f5
frequency (Hz) 270 2140 2950 3900 4950
Amp (dB) 0 -12 -26 -26 -44
bw (Hz) 60 90 100 120 120

Soprano 'o' f1 f2 f3 f4 f5
frequency (Hz) 450 800 2830 3800 4950
Amp (dB) 0 -11 -22 -22 -50
bw (Hz) 70 80 100 130 135

Soprano 'u' f1 f2 f3 f4 f5
frequency (Hz) 325 700 2700 3800 4950
Amp (dB) 0 -16 -35 -40 -60
bw (Hz) 50 60 170 180 200

Alto 'a' f1 f2 f3 f4 f5
frequency (Hz) 800 1150 2800 3500 4950
Amp (dB) 0 -4 -20 -36 -60
bw (Hz) 80 90 120 130 140

Alto 'e' f1 f2 f3 f4 f5
frequency (Hz) 400 1600 2700 3300 4950
Amp (dB) 0 -24 -30 -35 -60
bw (Hz) 60 80 120 150 200

Alto 'i' f1 f2 f3 f4 f5
frequency (Hz) 350 1700 2700 3700 4950
Amp (dB) 0 -20 -30 -36 -60
bw (Hz) 50 100 120 150 200

Alto 'o' f1 f2 f3 f4 f5
frequency (Hz) 450 800 2830 3500 4950
Amp (dB) 0 -9 -16 -28 -55
bw (Hz) 70 80 100 130 135

Alto 'u' f1 f2 f3 f4 f5
frequency (Hz) 325 700 2530 3500 4950
Amp (dB) 0 -12 -30 -40 -64
bw (Hz) 50 60 170 180 200

CounterTenor 'a' f1 f2 f3 f4 f5
frequency (Hz) 660 1120 2750 3000 3350
Amp (dB) 0 -6 -23 -24 -38
bw (Hz) 80 90 120 130 140

CounterTenor 'e' f1 f2 f3 f4 f5
frequency (Hz) 440 1800 2700 3000 3300
Amp (dB) 0 -14 -18 -20 -20
bw (Hz) 70 80 100 120 120

CounterTenor 'i' f1 f2 f3 f4 f5
frequency (Hz) 270 1850 2900 3350 3590
Amp (dB) 0 -24 -24 -36 -36
bw (Hz) 40 90 100 120 120

CounterTenor 'o' f1 f2 f3 f4 f5
frequency (Hz) 430 820 2700 3000 3300
Amp (dB) 0 -10 -26 -22 -34
bw (Hz) 40 80 100 120 120

CounterTenor 'u' f1 f2 f3 f4 f5
frequency (Hz) 370 630 2750 3000 3400
Amp (dB) 0 -10 -26 -22 -34
bw (Hz) 40 60 100 120 120

Tenor 'a' f1 f2 f3 f4 f5
frequency (Hz) 650 1080 2650 2900 3250
Amp (dB) 0 -6 -7 -8 -22
bw (Hz) 40 60 100 120 120

Tenor 'e' f1 f2 f3 f4 f5
frequency (Hz) 400 1700 2600 3200 3580
Amp (dB) 0 -14 -12 -14 -20
bw (Hz) 70 80 100 120 120

Tenor 'i' f1 f2 f3 f4 f5
frequency (Hz) 290 1870 2800 3250 3540
Amp (dB) 0 -15 -18 -20 -30
bw (Hz) 40 90 100 120 120

Tenor 'o' f1 f2 f3 f4 f5
frequency (Hz) 400 800 2600 2800 3000
Amp (dB) 0 -10 -12 -12 -26
bw (Hz) 40 80 100 120 120

Tenor 'u' f1 f2 f3 f4 f5
frequency (Hz) 350 600 2700 2900 3300
Amp (dB) 0 -20 -17 -14 -26
bw (Hz) 40 60 100 120 120

Bass 'a' f1 f2 f3 f4 f5
frequency (Hz) 600 1040 2250 2450 2750
Amp (dB) 0 -7 -9 -9 -20
bw (Hz) 60 70 110 120 130

Bass 'e' f1 f2 f3 f4 f5
frequency (Hz) 400 1620 2400 2800 3100
Amp (dB) 0 -12 -9 -12 -18
bw (Hz) 40 80 100 120 120

Bass 'i' f1 f2 f3 f4 f5
frequency (Hz) 250 1750 2600 3050 3340
Amp (dB) 0 -30 -16 -22 -28
bw (Hz) 60 90 100 120 120

Bass 'o' f1 f2 f3 f4 f5
frequency (Hz) 400 750 2400 2600 2900
Amp (dB) 0 -11 -21 -20 -40
bw (Hz) 40 80 100 120 120

Bass 'u' f1 f2 f3 f4 f5
frequency (Hz) 350 600 2400 2675 2950
Amp (dB) 0 -20 -32 -28 -36
bw (Hz) 40 80 100 120 120

[MitchK1989]

I've seen that chart too, but I disagree about the whole "needing 3 but 5 is preferred". You can get some pretty vowel-y sounds out of just two band passes in parallel. Also the whole "need to be in parallel" thing is kind of irrelevant here since we're using a parametric EQ to create peaks rather than using filters to cut everything BUT the formant frequencies out.

[Dave Bourke]

The Z-Plane architecture is basically a normal filter topology (lowpass/highpass/bandpass/notch) with some peaking eq bands added in. That's how they do those formant-type sweeps.

Back in the days this was resolved with some tricks to tame the maths. It unfortunately meant that each 14-pole filter had only 2 degrees of freedom (or was it 3?), such as cutoff and resonance. Or cutoff and vowel. So they shipped their stuff with a gazillion of presets for various filter sweeps.

Yes! That explains why my Morpheus manual illustrates more than 190 "templates" or setups for the filter. Something that always puzzled me...

Nowadays all it takes is adding in a parameteric eq with 3-5 bands into a normal oscillator-filter-amplifier structure. And that's exactly what FilterscapeVA does. Only, in Filterscape you have loads of degrees of freedom because you can modulate any parameter of each band separately. Hence FilterscapeVA is you easy to use "DIY Z-Plane box".

Urs

Thank you. That's wonderful news for me, Urs. My EIV died some time ago and I've moved all my samples to Kontakt 2/3. Unfortunately, the lack of a Z-Plane filter has meant that many of my home-brew sounds haven't been the same. So this means I can insert Filterscape on Kontakt and properly rebuild my presets to sound the way they did on the EIV.

Thanks a million for this information.

Kind regards.

[Urs]

Sheesh... be careful though... the stuff in the EIV was very well thought out and possibly tuned to death. A convincing recreation might not be easy. And while the snapshot-eq in Filterscape might be one of the easiest tools to recreate such things, it's not a pre-voice thing (as opposed to the synth...). Much of the magic of teh EIV might be owed to its per-voice filters...

[Dave Bourke]

OK, many thanks for the tips, Urs. I think Filterscape, at the very least, should enable me to get part of the way there. And who know, it may even help me to improve on the originals.

Kind regards.