# DEF-like filter for K2?



## BH (Jun 20, 2007)

I'm interested in a DEF-like filter for K2 - anyone?


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## Thonex (Jun 20, 2007)

What exactly does the DEF filter do? Maybe it can be closely approximated in K2 with clever Filter or EQ programming via a script.

Cheers,

T


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## Rodney Glenn (Jun 20, 2007)

Thonex, I've been wondering the same thing. The DEF and PRF filter functions are described in detail on this page (from the Tascamgiga site):

http://www.tascamgiga.com/gv/filter.html

Judging from the description, it seems there's some sort of phase corrected morphing going on.

Didn't SvK (user on this forum) do something along these lines using filters in K2?

R


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## Thonex (Jun 20, 2007)

Thanks Rodney.

ok.. in simplest terms... from what I understand after reading the link you provided (thanks for that) it seems like the DEF could be very simple if all it's doing is following the frequency of the note you play on the keyboard and then doing some cutting or boosting (depending on this application).

If so, this can already be done in K2 without scripting by assigning Keyboard as a modulator the the Frequency of a filter... and I presume an eq. But there is probably more going on than that.

Anyone use DEF on a Giga studio that can accurately describe what it does?? I have GS3 on one of my computers but I believe I took out all the Giga Libraries on it. So... I'm hoping someone else can chime in here to de-mystify this filter.


based on this explanation... it would be easy to get the same effect as in GS3... :



> DEF - Dynamic Expression Filter
> The DEF filter provides a continuous, note-specific, morphing filter for adding expressiveness before and after sustaining note-on events. Using a traditional MIDI controller, the user can accurately and continuously morph the frequency response of sustaining samples between velocity dynamics, even after note-on events have occurred.
> 
> What this means for GigaViolin users is the ability to perform phase accurate real-time crescendos and decrescendos using a single sustaining note, effectively replacing the need for layered X-fade instruments that increase polyphony and introduce phase inaccuracies. The result is a more lyrical and "live" sounding instrument that gives the user expanded depth of control over musical phrasing and dynamic range.



All filters are different... so who knows for sure.

Cheers,
T


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## Fernando Warez (Jun 20, 2007)

I do miss it a bit. For brass mainly. But i would not go back to GS3 just for DEF that's for sure. SIPS and other script adds way more than DEF alone.


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## Rodney Glenn (Jun 20, 2007)

In case anyone is interested, here is the thread by _SvK_ about his K2 brass/woodwind filtering technique that I mentioned in my previous post:

http://vi-control.net/forum/viewtopic.php?t=5067

I'm not sure how relevant it is to this specific discussion about DEF filtering, but I think its interesting nevertheless. 

R


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## tfishbein82 (Jun 20, 2007)

Isn't that exactly what DEF is supposed to do? Simulate timbre changes when volume changes.


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## Thonex (Jun 20, 2007)

tfishbein82 @ Wed Jun 20 said:


> Isn't that exactly what DEF is supposed to do? Simulate timbre changes when volume changes.



Well... this is what I'd like to get to the bottom of.. does it "simulate timbre changes" or is it just a filter that follows pitch? In the latter case it would be easy to do that on K2. 

Cheers,

T


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## Mark Belbin (Jun 27, 2007)

Dang...didn't get here in time to defend the DEF....

Here's a brief:

The DEF is a continuous morphing filter, meaning that it is not as simple as, say, a lowpass with cutoff freq assigned to a controller. Not even if you add a resonance control and a bandpass or highpass to boot. What it does is morphs several bands of parametric eq from one set of Fc/Q/dB settings per band to another. The extreme settings of of these bands are calibrated to emulate the extremes of velocity (as cross referenced with real "reference" samples. which are discarded after calibration), when applied to just a mezzo-forte (or other, but this is typical). So it is similar to what SvK did, though if I recall correctly, he only used filtering to emulate extremes of the quiet part of an instrument's dynamic range. That said, he did a pretty amazing job!

Some other points about the DEF:

-It is note-specific; A completely different set of filter coefficients can be applied to each semitone of an instrument. This fact means that it can accomodate anything from a set of percussion accessories mapped to the keyboard, to solo or ensemble strings. In addition to this, it can be used to produce some wild synth effects.

-With samples that were recorded correctly, it can emulate a very wide dynamic range with just one layer. I am testing a new instrument with this method (using the absolute quietest samples I can record for calibrating the ppppp range. You would not believe that the result uses just one velocity layer. 

-The DEF control can be assigned to velocity, any midi CC#, or a combination thereof.

-The DEF, when applied over the range of a portamento, can be set to significantly reduce the chipmunk effect of stretching a sample beyond its range. This is the PRF (portamento reshaping filter), which uses the same calibration method as the DEF, but applies strictly as a morphing filter, as opposed to the combination of a filter with volume. As before, correct use involves samples recorded with this purpose in mind. For example, any inclusion of ambience is likely to interfere with one's ability to convincingly calibrate the filter for this purpose.

-When excess velocity layers are discarded by means of the DEF, instrument programming in gigastudio becomes flexible enough to compare to K2 scripting. A tremendous amount of control is possible, though this fact is largely neglected due to the fact that TASCAM never did proliferate all the information necessary for users to implement this feature in full. I have an agreement with TASCAM to carry out such proliferation in the form of tutorial material on the finer points of the processes involved. Stay tuned...

That last point is a stab in the dark; I don't own K2, so I'm not sure to what extent it surpasses Giga at its best. I do know that it is widely accepted as light years ahead, mostly due to scripting. That said, I have a feeling that no one here quite knows what Giga is capable of when it's most powerful features are unlocked. That's the reason for the above mentioned tutorials. I hope those of you who have/use gigastudio will check this material out when it is released. These features have been sorely underdocumented by TASCAM, and I am glad that they have accepted my offer to help share the techniques of using them. 

Sorry to invade the Kontakt forum with this blatently pro-giga post.... :wink: 

Mark Belbin
Wavelore Instruments
www.wavelore.com


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## Rodney Glenn (Jun 28, 2007)

Hi Mark

Thank's for your detailed description of the DEF feature, much appreciated.

As for the whole Giga vs Kontakt discussion, I'm sure they both have their pros and cons so maybe its more a question of what features are most important to you etc.

I can't speak for the other Kontakt users, but for me the scripting possibilities was indeed the most important feature and was what ultimately made me go for K2. However, had GigaStudio been offering the same scripting possibilities, then I might have gone either way.

Anyways, although features like DEF might not be possible to replicate exactly in K2, we might at least simulate it to some extent using scripting. In the end, all that really matters is how it sounds...so whatever tool works for you is fine IMO.

Cheers

Rodney


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## Mark Belbin (Jun 28, 2007)

Hey guys,

Thanks for your interest in this.

@Rodney: You're absolutely right. The pros and cons of either platform will be different depending on the user. It would seem that giga has more cons than pros, and vice versa for K2, though I believe that this is kind of a misrepresentation based on the aforementioned mystery surrounding giga's higher levels of functionality. As far as scripting is concerned, the DEF is part of the solution to giga's apparent lack of flexibility, as it frees up loads of room to implement more intelligent programming while reducing the size of the library, and eliminating phasing artifacts. As above, as a giga-only guy, I'm not qualified to say whether this levels the playing field entirely, but I'm certain that it closes the gap considerably.

@Ben: Oh, come on-Giga vs. K2 arguments are fun! :wink: Actually, I'm not interested in them either, but I will take any opportunity to discuss giga's neglected powers. There was a thread at NSS a couple of years ago, which was a bunch of people saying, "K2 scripting is cool, but what about giga's DEF? How does it work? Why hasn't TASCAM explained it to us? etc, etc." I wish I knew then what I know now.

@Thonex: I am due to get back to work on my DEF tutorial stuff. This will include sample materials for people to learn DEF calibration hands-on, as well as audio examples. I will prioritize the A/B samples so they can be posted sooner than later. 

Cheers,
-Mark


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## Fernando Warez (Jun 28, 2007)

Marc, first thanks for the explaination.

I just wanted to tell you the main advantage to switch to K2 as i see it. Other than the scripting capability and the fact that i can have all my libraries in one format. 

The reason is memory management. I've just loaded all my performance legato from VSL Opus 1 and I've only used 321.52 MB of memory. Which means i still have around 780 MB left on a 2 GB system(1.5 GB total). Note that i could not even load all my perf legato(from Opus) on the same system if i remember correctly. 

Granted this is a bit of an extreme settings. I've set the Override instrument preload size to 12.00KB and may have to set it back to 18.00 KB but still. 

About the DEF, worse case scenario i may reinstall GS3 and sequence and record dynamics for brass a la VSL(1 sec, 2 sec, 3 sec etc,) to avoid phasing, and import it back in K2. I don't know, it just crossed my mind. But it would be great to have this in K2. Something tells me NI will add something similar in K3. I hope.


P.S. I'm on Pc BTW. I don't think you can adjust the Override instrument preload size on a Mac.

P.P.S. I don't mean to start a war with this either BTW.


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## nadeama (Jun 28, 2007)

Mark,

I can't wait to have a look at your DEF/PRF tutorial. I love the DEF and use it in pretty much all my Giga libraries, but maybe I could tweak it to sound even better on specific instrumets. The PRF I'm afraid I've never been impressed with, even in libraries like Sonic Implants where they custom programmed it to fit their specific needs. I'll admit that I like the sound of the SIPS script much better in Kontakt. But hey, maybe once I see your tutorial I'll be able to tweak it to sound awesome...

Any idea when the tutorial will be ready?

As for the Giga/Kontakt war, there's no need for it. You should all o as I do and use both! They both have their strengths and I wouldn't want to be without one or the other. If you can afford it, it's great to have the best of both worlds. I'm even running both at the same time on the same PCs, and it's working out great.


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## Hannes_F (Jul 26, 2007)

For the records ... I may be wrong but I think although there has been not much been talked about this the basic idea has been brought up by Tom Hopkins for GPO. 

Since he wanted to create an orchestra sketchpad that could run on a laptop (known as GPO ) he replaced the velocity layers by differently EQ'ed versions of a single sample. As an idea this is brilliant. Plus, he later added an automateable EQ band that works similar to SvK's idea ... who probably came up with this idea independently. But the basic ideas are already in GPO since years. Very handy, and the additional EQ allows astonishing results even with GPO, however hardly anybody of the current users seem to be aware of it.

I have been fiddling around with an extension of that idea - finding EQ settings with a match EQ and then automating multiple bands of a parametric EQ with one cc. But my CPU horsepower at that time did not allow to do this for many channels, so I returned to the one-band solution which is something like the first-order approximation of the ideal.

How many EQ bands does DEF automate? Is there any match EQ or something that allows to find the proper settings for the EQ extremes?


Hannes


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