12 – Crossfading Mals & Filters

Since Ed’s Thor Shaper article, I’ve been thinking about how to use this information in real-world examples. One idea is to crossfade the Grain Samples in the Malstrom and another idea is to crossfade all 4 Thor filters to affect one sound source. Lots of fun!

Since Ed’s Thor Shaper article, I’ve been thinking about how to use this information in real-world examples. One thought came from a post I saw on the Props forum. Basically, the issue was that you can’t assign the Malstrom Grains to a Combinator Rotary to effectively switch between the 80+ Grain Samples. It’s pretty easy to assign and switch between Modulator waveforms using a Rotary, but not the actual samples in the Malstrom. So this got me thinking of how you could go about switching between these Samples. And truth be told, there’s probably some really obscure way to do it which uses Thor and some heavy CV connections. But here is something that might just inspire you and be the next best thing.

You can download the project zip file here: crossfading-malstroms-and-filters. This file contains 2 rns files with the Combinator setups explained below. One is a 16-Malstrom crossfader, and the other is a 4-way Thor filter crossfader. I would recommend you download them and open them up as you read. It will make things a little easier that way.

Crossfading 16 Malstrom Grain Samples

In this setup, I’m using 16 Malstrom devices and each device is sent to a Mixer Channel in two 14:2 Mixers. The CV from the various Thors are sent to the Mixer Levels, where the level trim knobs are pushed all the way right, and the Mixer channel Levels are set to zero. If you haven’t already seen Ed’s interesting and enlightening tutorial on the subject, you should read it here: Ed’s Thor Shaper Tutorial. It goes through using the Sine Wave Shaper in Thor to create a 4-way Crossfader. In this way, you can cross-fade between 4 different Malstroms. Each Malstrom’s Oscillator A is set to a different Sample.

Since you have 4 Rotaries, each Rotary is set to 4 Malstrom devices. Giving you a total of 16 different Oscillators. Also, since one or more oscillators will be playing at any one given time, I’ve set up each button on the Combinator to mute the specific series of Oscillators. Button/Rotary 1 affects the first group of 4 (Malstroms 1-4), Button/Rotary 2 affects the second group of 4 (Malstroms 5-8), and so on. Only 10 Malstroms should be applied to a single Mixer because you can only map 10 parameters from any one device to the Combinator, and you need all 10 channel mutes mapped to the various Combinator buttons.

To take this a step further, you could create 6 Combinators, which together would contain the full 82 Oscillator Samples used by the Malstrom. Then you could crossfade between any oscillator you like. The sweet spots for each of the rotaries are as follows:

0 = Oscillator 1 Full Level

42 = Oscillator 2 Full Level

85 = Oscillator 3 Full Level

127 = Oscillator 4 Full Level

Any integer between those values will provide a crossfade between the two Oscillators on either side of the value. This can be seen as a downside or an upside. If you want a pure switch between Oscillator 2 and 4 for example, you can automate the Rotary to go straight from 40 to 85 in your sequencer using a Rotary automation lane. In this sense, you can use the Rotary as a 4-way button switcher between each Oscillator.

On the downside, you couldn’t effectively crossfade between Oscillator 2 and Oscillator 6 (on Rotary 2) the way the current Combinator is set up. But if you Reorganize the way the buttons mute, you could effectively do this. I’m open to anyone who has any other suggestions on how this could be achieved. Another downside is that since a different Malstrom is used for each Oscillator, you’ll have to tweak the settings on each Malstrom to get exactly the sound you want. If you want to keep everything consistent between all Malstroms, you’ll have to do it through automation (the easiest way I think). Simply automate one parameter on the first Malstrom in the sequencer, and copy that automation clip into every other Malstrom’s automation lane. It’s a bit of a pain, but it will keep all Malstroms in line, if that’s what you want.

On the upside, since there are 16 different Malstroms, you can fine tune the sound of each of them separately. If you have all the mutes off, you can effectively crossfade between 4-8 Malstrom sounds/devices at once just by shifting the Rotaries around. This adds some very interesting Sound Layering potential.

As it stands, the first 16 Oscillators from the Malstrom are applied to the 4 Rotaries on the Combinator. As I said, you could build up a stack of 6 Combinators to include all the Malstrom Oscillators. In this way you can build up various sounds and switch between the various Oscillators. Does this help anyone out?

Crossfading all 4 Thor Filters, and then some. . .

Next, let’s take a look at how we can crossfade all of Thor’s filters to affect one synth sound. In this case, it’s fairly simple to set up. First, create a Combinator, and set up Ed’s 3 Sine Shaper Thor’s to handle the CV like the previous example (along with a 14:2 Mixer). Then create a Thor and load up a synth sound. Start off with something simple so that you can really hear the different filters affecting the sound. Then create a Spider Audio CV Merger / Splitter, and send the synth’s Left and Right Audio Outputs to the splitter’s inputs. Create 4 Thors underneath the splitter and send each of the 4 splits to these respective Thor’s Audio Inputs 1 and 2. Finally, send the 4 Thor’s Left and Right Audio Outputs to the first four 14:2 Mixer channels.

The setup with The Sine Shaper CV and Audio outputs from Thor into the Mixer
The setup with The Sine Shaper CV and Audio outputs from Thor into the Mixer
The Thor Synth Audio being split and sent through the 4 Thor Filters
The Thor Synth Audio being split and sent through the 4 Thor Filters

On the front of the Rack, add a Low Pass Ladder Filter in the first Thor’s Filter 3 Slot. The settings for this filter are shown in the image below. In addition, add the following into the Modulation Bus Routing System (MBRS):

Audio In1: 100 > Filt3 L.In

Audio In2: 100 > Filt3 R.In

The Low Pass Ladder Thor Filter settings on the front Panel
The Low Pass Ladder Thor Filter settings on the front Panel

Enter the same settings in the other 3 Thors, but with different filters, so you have the State Variable filter in Thor 2, Comb filter in Thor 3, and Formant filter in Thor 4. While you’re at it, play around with the Global ADSR envelope so that it sounds to your liking for the 4 different filters. It’s ok if these settings are different for each filter. This will just make your sound more interesting. One thing I kept the same across all 4 Thor Filters is the FX section (Delay and Chorus). This way, when the filters are transitioned, the FX remain similar across the board.

Now let’s turn to our Combinator section and do some serious routings in the Mod Matrix. Here’s the settings you will need for each of the Thor Filters (they are the same for all 4, but must be applied to all 4):

Rotary 1 is reserved for the Filter Crossfade, so I’m not going to go over it here. You can see it in the Project File rns.

Rotary 2 > Filter 3 Freq: 0 / 127

Rotary 3 > Filter 3 Res: 0 / 127

Rotary 4 > Filter 3 Global Env Amount: 0 / 127

Button 1 > Delay On: 0 / 1

Button 2 > Delay Sync: 0 / 1

Button 3 > Chorus On: 0 / 1

Button 4 > Filter 3 Global Env Invert: 0 / 1

Mod.W > Filter 3 Drive: 50 / 127

The Combinator Mod Bus Routing settings for each of the Filters
The Combinator Mod Bus Routing settings for each of the Filters

Now, what’s happening is that the Mod Wheel controls the drive amount on each of the Filters, While Rotary 1 cross-fades all the filters. This is the main Rotary, and it has the same sweet spots as the previous Malstrom patch. Rotary 2 and 3 control the Frequency and Resonance of the filters, and Rotary 4 adjusts the Envelope of the filter. Button 4 inverts this envelope. The remaining buttons are left for the Delay, Delay Sync and Chorus. Since all the parameters are the same for all the filters, they all shift together. This can be a positive or a negative. You can’t individually set the filters, but at least they sound pretty good when transitioned. Depending on your ADSR settings for the Global Filter, the Envelope Rotary and Envelope Inversion Button may be different for each filter. But as I said before, this can add some nice variety to the sound.

Use this Combinator as a template for your own sounds. All you have to do is add your own patch into the Thor “Synth” or change the Thor “Synth” to any other Synth or Sampler device if you like. Then you’re in filter crossfading heaven.

A huge thanks to Ed for being the inspiration for these patches. Please let me know what you think and if you can think of any other applications that this crossfading technique can have, by all means share it with us. Until next time, have fun with these.

3 thoughts on “12 – Crossfading Mals & Filters”

    1. Thanks Ed. I’m not certain the Malstrom is as “usable” as I would like. I do, however, really like the idea of crossfading the Thor filters. I can see that being very useful for shifting the sound of a long slow evolving Pad, for example. Or on the other end of the spectrum, shifting short glitchy sounds and bouncing them around from one filter to the next. You could probably even set up 4 Screams or 4 Vocoders to shift between the various effects. Lots of interesting possibilities. Thanks for shedding light on the use of the Thor Shaper Sine wave for crossfading purposes.

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