emusonacid! legacy

Just a little tip for getting your head around the Z-plane filters:

1) Make a preset using a white noise sample

2) Connect your sampler to a computer running live spectrum analyzis

3) Without using any filtering - check that the the spectrum show a flat spectrum when playing the white noise preset

4) now use a the different lowpass filters combined with a midi controller for filter and resonance. you should see the shape of the filter on the spectrum analyzis. turning up the resonance will give a better visual repesentation, especially with the band pass filters.

5) With the z-plane filters, set all parameters in a neutral position (this will mostly be 0) - in other words make sure that the filter is not colouring the sound (check that the spectrum is flat). Then tweak one prarmeter at the time while sweeping filter freq with a controller.) watch the spectrum analyzis.

I think you will soon discover how the z-plane filters work, and actually learn it by first hand experience.

have fun!
emugonzo

any chance of posting a couple screenshots of what you are talking about.


on the topic of z-planes, are the filters in the emu called morph filters the z-planes? and how many are there suposed to be.

just messed aorund with the filters section for the first time today and cant remember how many i saw, but it didnt seem like to many.

anyway, thanks for the tip. if i ever get a frequency analyzer ill check this out

you have a great set of frequency analysers ... I beleive you earthlings call them ears.

Okay, why are no practical z-plane tips ever told? Is it the 'big secret'? Do people feel they're at an advantage over others and therefore not pass on knowledge? Or are the results got at random with no real logic and therefore difficult to formulate? Or none of the above?
I feel I've learnt an amount, but don't fully understand how the zplane is working. I've found no resources on the net and I wonder how my Z Planes compare? Mine are usally way too bassy on certain notes, way too weedy on others.

Thanks,
Ezman
...hic.....

KRS-2 wrote:any chance of posting a couple screenshots of what you are talking about.

I'm 99% sure that someone posted a graphical representation of this quite a while back, probably not on this forum. I'll see if I can remember where I saw it - does anyone else remember where it was?

[quote="ezman"]Okay, why are no practical z-plane tips ever told? [quote]

I honestly think nobody is 100% sure of how the hell they work, so people just find what works and go with it. I sort of do. The Peak/Shelf Morph is super dope, but to me, there's too many parameters for me to work it out logically. Specifically, why are there 3 Peak parameters?

Anybody REALLY understand this filter?

Sound on Sound wrote a nice article that mentions the morph filter.

Klaseed wrote:

ezman wrote:Okay, why are no practical z-plane tips ever told?

I honestly think nobody is 100% sure of how the hell they work, so people just find what works and go with it. I sort of do. The Peak/Shelf Morph is super dope, but to me, there's too many parameters for me to work it out logically. Specifically, why are there 3 Peak parameters?

Anybody REALLY understand this filter?

lol you may be right ... it's kind of suspicious that the manual doesn't explain it at all.

OK Z-Plane in its most basic form is just being able to modulate between two different filters. So ... in the EQ one (not in front of the EMU so bare width) you have 2 frames (each is an EQ) and a morph parameter. Basically you can have it EQed two ways (fairly self explanitory ... werks like the the single non-zplane EQ filters in the EMU - which I looooove BTW) and then morph between the two.

But I think that most already know this, right?

The real question on everyones mind is ... what the fuck is the Peak/Shelving Filter and why is it so weird?!?

In recent months I've come to understand it a bit better. Now, explaining it clearly is going to be harder ... but I'm now at a point where I know what each parameter is going to do to the sound. I'm hoping that someone on here knows it better than I because a clear and concise explaination would greatly benefit me as well (fuck me I sound like a twat today ... I swear I don't actually talk like that).

Before I start ... a word to the n00bs (yeah, I'm talking to you!) ... if you are adjusting the frequency of the frame on a Z-plane but it's not changing the sound: make sure that if the morph parameter is on 255 that you are changing the parameters in frame 2, not in frame 1. Conversly, if morph=0, only the parameters in frame 1 will have an effect. This took me a couple of months of being pissed off and thinking that they were bullshit when in fact all I had to do was adjust frame 2 cos morph=255. But I digress ...

OK ... this is what I know about the shelving filter:
.......................frame 1..........frame 2
Morph: 255.......Freq: 81.........Freq: 81......(can't remember the exact
Gain: -24.0.......Shelf: -64.......Shelf: -64....lower limit for the freq
.......................Gain: -24.0 Gain: -24.0...parameter could be 81hz)

Basically, the shelf parameter (ok ... the second one ... I beleive its called shelf) controls the general shape of the filter ...

A negative value will produce a shelf (vaguely) like this:

a......________________
m......................................\
p.........................................\..........(pay no mind to the "."s)
l............................................\
i..............................................\
t...............................................\
u................................................\
d..................................................\______________________________
e (amplitude on the Y-axis)

.....................f.....r.....e.....q.....u.....e.....n.....c.....y (on the X-axis)

A positive will produce a shelf like this (same X and Y):

...........................................................__________________________
........................................................../
......................................................../
....................................................../
..................................................../
................................................../
................................................/
_______________________/

Basically think of the negative shelf as a lowpass, but one that does not completely cut the highend out. Conversly, the positive values of shelf act like a highpass where the lowend is not completely cut out.

(at this time I'd like to state that I could be wrong and would like to ask anyone who gets this better than I do to set me straight)

The freqency parameter is pretty self-explainatory. Its the frequency where the change in amplitude takes place (represented by forward and backward slashes).

-A point of note: try taking an unfiltered bass tone and placing it in this filter. When shelf = -64 and freq = 81hz (or whatever the lowest is) it sounds like the bass is emphasized a bit but you can still hear the high freqencies. But when you change the freq to 300hz it seems to strip the sound of its top end. I believe that this is because when the freq is all the way down, almost all of the sound "rests" on the lower (in amplitude, see above diagram) shelf. The highend is therefor not much quieter than the rest of the sound. However, When you set the freq to 300hz (or whatever) much more of the sound "rests" on the upper (in amplitude) shelf, causing a much greater difference in volume between the lower and higher frequencies.
^^^This is independent of the morph function.

The gain parameters (OK this is where I start losing the plot). I know that if I bang these up the freqency selected for the frame will be boosted. The only thing is, what about the negative values? ... sometimes they don't seem to do anything untill you cross 0 into + values?

And the gain parameter under the morph. WTF is this?!?!?!? I know how it sounds ... it seems to lessen the overall effect of the z-planes ... ezman ... if your sounds are too bassy or top heavy (freq wise) this will help to lessen the extremity of the filter(assuming you want to keep your freq settings the same). This gain seems to have a great effect when approching 0 from - values.

edit :(ezman you could also try reducing the amount of shelving going on ... ie. if too bassy change from -64 to -15 or something)

Anyway ... that's about the extent of what I understand. I'm sure that I probably got something wrong so speak up and set the record straight!

If you know what the gains do (especially the one under the morph parameter) and can explain it other than saying it "changes the sound" please let me know!

damn great explanation/graphs and all man. really appreciate you guys takin the time to explain stuff like this. this board is fast becoming my favorite spot for pure knowledge.

cant wait to mess with this now. i am at the point you were where i was changing all the parameters in the filter and nothing was happening. I was also wondering why everyone thought the z-planes were so great

anyway, thanks again

Cheers for that Madmax. I'm definitely understanding the peaks underneath the low and hi morphs but the one under Morph is buggin the hell out of me

I had a theory for a moment that that one exists so you can balance out the levels of the lo and hi and then bring up the gain or lower it if needs be using Peak. But it seems to act almost like normal resonance on a low or hi shelf filter. Hmmmmmmm. I will learn this sucker.