Where's the Z's?

[Harbinger]

We still don't have an end-all authoritative page on how to use the Zxx command, not only with resonance-shifting, but also VST manipulation. I'm interested to know what i can and can't do with this powerful FX command. We have scattered info among the site's forum, but nothing even in the Wiki. Anyone know enough and interested enough to write up this important info??

Questions i'd like answered in such an article:

1. How do you shift resonance on the playing of an instrument, and how can you get the computer to randomize the resonance playback?
2. How can VST effects parameters be used when composing on a channel, and how does it affect resonance-shifting, before or after using other Zxx commands?
3. What are the known issues and limitations?

etc, etc, etc....

Let's make an official teaching document.

[Sam_Zen]

I still have no idea whatsoever about these commands, so I find this a very nice initiative.

[LPChip]

I did find 2 relevant topics, although I admit, the info is not complete.

http://forum.openmpt.org/index.php?topic=1889.0

http://forum.openmpt.org/index.php?topic=1392.0

I might write a tutorial for the Zxx one of these days, but if anyone writes one and posts it here, I'll be happy to add it to the wiki for you.

[älskling]

I'm way too idle to write a guide, but I can give whoever writes it some tips. If you spot any errors don't mind correcting me, I might very well be wrong about many things.

When using midi macros (Zxx) to control filter cutoff/resonance it works lite pretty much any other effect. The default values are Z00 to Z7F controls the cutoff and Z80 - Z8F controls what is usually called resonance.

By default global filters (S9C) are enabled, which means the cutoff/resonance values stays the same for new notes. Changing to local filters (S9D) resets the aforementioned values to their default (Z7F and Z80 respecively).

In the Song Properties window you can enable High Filter Range, which means that the cutoff frequence is doubled and the transition from no cutoff to minimum cutoff is less apparent. Unfortunately I don't know the exact frequencies, then again who cares eh?

An option to using Zxx commands to control the filter is to use the reso and cutoff sliders in the instrument window. It's a relativley new feature, and since it's instrument specific rather than channel specific (like the Zxx version) I don't know how predictable the results are when combining the two.

There are two modes for the filters in mpt, high pass and low pass. You *can* set filter mode with the Zxx command, but I don't really know how... I'm confident I've done it, and I thought there was a special command for it (like S9x something) but apparantly there isn't. If you want to use high pass mode, then the easiest way is to set it in the instrument editor. Not the best way, but a way.

Another newish feature is th \xx command. It works like Zxx, but instead of just setting the value it slides to it (smoothness depending on ticks resolution I suppose) to create a smoother transition.

About your question on how VST's affect internal filters, they don't. The output of the channel or instrument (preferably) is simply sent to the effect of your choice, and if it's filtered then that's what's sent. Note that you should select the right macro to control what you want, using the SFx command. the first macro, SF0, is set to control the internal filter by default.

The only issue I know of (apart from the lack of documentation) is that it's easy to forget to turn the filters off.

[Sam_Zen]

Great.
I understand these filter settings and ranges now. On an analog filter resonance would be called 'the Q-factor'.
Isn't this already enough data to have a reason to move this thread to the techdocs department ?

One question though.
I read "midi macros (Zxx)". Does this mean that the filter only affects sounds coming from a midi-bank, not samples ?

[älskling]

I read "midi macros (Zxx)". Does this mean that the filter only affects sounds coming from a midi-bank, not samples ?

No, they're just called midi macros for some reason unknown to me. Perhaps that was the original intention?

Also, I'm not sure what you mean with sounds coming from a midi bank. The internal filters only affects samples, not the sound of any plugins.

[LPChip]

They're called midi macro's because setting the filter and controlling plugins is done through the midi language.

[Sam_Zen]

I'm not sure what you mean with sounds coming from a midi bank.

Good question, I'm not sure either, because I never used MIDI in tracking.
But I got the impression that I can open open up a bank and pick some sound from the list to become an instrument.
Because the same is happening when importing a .MID file.

[LPChip]

I'm not sure what you mean with sounds coming from a midi bank.

Good question, I'm not sure either, because I never used MIDI in tracking.
But I got the impression that I can open open up a bank and pick some sound from the list to become an instrument.
Because the same is happening when importing a .MID file.

I think he means when you use a .DLS (like the gm.dls) and load it into OpenMPT. that Zxx only controls that. This certainly is not the case, because when you load an instrument through a soundbank, it will import, and convert to samples+instruments.

[Sam_Zen]

Yes, that's what I meant. Thanks for clarifying this. One question to be sure though :
- Will this sound converted to samples+instruments also be saved in the module-file, so, after that, the soundbank isn't necessary any more?

[Harbinger]

By default global filters (S9C) are enabled, which means the cutoff/resonance values stays the same for new notes. Changing to local filters (S9D) resets the aforementioned values to their default (Z7F and Z80 respecively).

So what that means is that if i call a macro (say to control VST parameters), then i can still use Zxx in the same channel to go back to resonance-shifting (by calling a new note with its instrument)? Does the macro stop if i begin resonance shifting before the macro is finished within the same channel?

Thanks, alskling and LChip, for the info, but this stuff really needs to be put on one sheet, so i can print it and use it when i'm composing...

[älskling]

So what that means is that if i call a macro (say to control VST parameters), then i can still use Zxx in the same channel to go back to resonance-shifting (by calling a new note with its instrument)?

In my opinion "calling a macro" and "using Zxx" are the same thing, so I don't really understand the question... The macro you use within a channel is selected by the SFx command. Local filter mode just means the internal filter gets reset with a new note and has nothing to do with VST parameters. (apart from using macros)

Does the macro stop if i begin resonance shifting before the macro is finished within the same channel?

The macros aren't constantly running, they're simple executed once. If you send a macro to a VST to change it's volume parameter, it just changes the volume parameter and that's it. If you change which macro to control with SF1, any Zxx commands after that will be according to the currently active macro but that doesn't change anything about what's been done with other macros earlier (unless they control the same parameters which doesn't make sense).

I think for things to make more sense one should think of controlling the internal filter and VST parameters as being two separate things that just happens to use the same commands.

this stuff really needs to be put on one sheet, so i can print it and use it when i'm composing...

I agree, I think this thread was moved a little early as it's still a discussion in my opinion.

[LPChip]

Yes, that's what I meant. Thanks for clarifying this. One question to be sure though :
- Will this sound converted to samples+instruments also be saved in the module-file, so, after that, the soundbank isn't necessary any more?

The samples + instruments will be saved in the file, so you don't need the gm.dls file after you've imported the sounds, unless ofcource you use the itproject file that uses references instead of direct includes.

[bvanoudtshoorn]

So, to use the Zxx macros, you basically do this:

1. Set up your configuration, so that each SFx command corresponds to whatever property you want to control, whether it's a plugin parameter or the internal filter controls.


2a. In your pattern, select the appropriate control by using the SFx command.
2b. Vary the parameters using Zxx and \xx (hard set and slide to value).



It's possible to control multiple params at a time, as long as there's a note playing in that channel. For example,

won't work (at least when I just tested it), but

works perfectly. Of course, you could get past this by setting the volume to zero for the unwanted note in channel 2.

[LPChip]

The second channel will also work without a note, if you apply the VST/VSTi to that channel directly.