Nov 122009

In this project I’m going to demonstrate a few ways you can use Thor’s filters, FX (Delay and Chorus), and LFOs creatively by routing any of your audio sources through Thor. This can be a great way to punch up some drums from a Redrum, or to create some new innovative sounds from any of the synths. Furthermore, you’re not limited to using only 1 filter. You can connect your audio through a series of Thor devices to gain access to more than 1 filter at a time. So let’s start our exploration.

Basic Audio Filtering through Thor:

  1. Open Reason. In the rack create a Combinator and inside the Combinator create a Thor, initialize the patch, and then create a Redrum underneath. Add a drum kit and create a simple pattern with a kick, high hat and a few other drums. Don’t make it too complex. Use about 4 or 5 drum samples to create the pattern.
  2. With all the hard work done, now we’ll do some routing. Flip the rack around and route the Left and Right audio output from the Redrum into the “Audio In 1” and “Audio in 2” on the Thor.
  3. Basic cable routing to pipe audio through Thor

    Basic cable routing to pipe audio through Thor

  4. Flip the rack back around, show the Programmer for Thor, and uncheck all the little green lights in the “note” section (the section that is dark and not light brown). Also, turn the analog osc.1 off, and bypass the Ladder Filter (Filter 1). Then turn off the routing between Osc.1 and Filter 1 (the little red “1” light). In the top device section, set Polyphony and Release Poliphony to “0” and turn off both trigger lights (Midi and Step Seq). The point is that you don’t need any of that mumbo jumbo.
  5. Add a Filter into the third Filter slot of Thor. A Low Pass Ladder or Comb filter works well with Drums, but you can use any filter you like.
  6. At this point, most people will press play and think that they should be hearing something. But we’re not finished yet. We need to reroute the default Thor audio signal. Here’s how to do that: In the MBRS (short for “Modulation Bus Routing Section”) of Thor, in the first row on the left, click on the “Source” and select the bottom-most option “Audio Input > 1” then set the “Amount” column to “100.” Click the “Destination” column and select “Filter 3 > Left In.” On a new row, do the same thing, but for Audio Input 2 as a source and “Filter 3 > Right In” as the destination.
  7. The MBRS at the bottom of Thor

    The MBRS at the bottom of Thor

  8. Now press play. You’ll hear the drum pattern, which is routed through Filter 3 in Thor, then to the Chorus and Delay section, and back out to the mixer.
  9. Optionally, you can use the FX (Delay and Chorus), or route the LFO2 to affect any of the parameters in Filter 3 or the FX. One thing I like to do is turn on both the Delay and Chorus. Then in the MBRS section, program the two FX Dry/Wet parameters to the two Rotaries. If you use amounts of +100 for both, then turn the actual Dry/Wet knobs on the FX all the way down, you create a controllable Delay and Chorus effect via the Rotaries. I also use the Mod wheel to control the Filter 3 Frequency or Resonance or both. That way, it’s all controllable. If you want to push it further, you can assign the LFO2 to affect the Frequency or Resonance via one of the Thor buttons. This all gives you a great degree of control over affecting the sound. Download the example file (at the bottom of this post) to see these routings.
The front of Thor, with all routings for the FX and LFO2

The front of Thor, with all routings for the FX and LFO2

First, here’s an example of the original sound:

Second, here’s an example with the audio filtered through Thor (remember, you can adjust the filter to taste):

As an aside, if you’re using Record and have an audio track, you can still route your audio through Thor, by cabling the direct output of the audio track to the Thor inputs 1 + 2 as shown below.

Routing an audio track in Record through Thor

Routing an audio track in Record through Thor

Audio Filtering through a Series of Thor Filters:

By now, you will have noticed that plugging audio through Thor gives you access to the global section (the parts of Thor that are light brown). What if you want the use of more than one filter. Let’s say you want your audio path to move this way: Audio Device > Formant > Comb > Low Pass Ladder? Well, it’s really quite simple. Follow the above directions to set up your first Thor, and then build upon that as follows:

  1. Flip the Rack around. Right-click over Thor and select “Duplicate Devices and Tracks.” Do this one more time. You should now have 3 Thor devices.
  2. Move the “Audio In” cables from the first Thor to the bottom-most Thor’s “Audio Ins” and then cable the “Audio Outs” from that bottom-most Thor into the Thor above’s “Audio Ins.” Finally, cable the “Audio Outs” from the middle Thor to the “Audio Ins” of the top-most Thor.
  3. Flip the rack around again to see the front. Then switch the bottom-most Filter 3 to “Formant” and top-most Filter 3 to “Low Pass Ladder.”
  4. Press Play and adjust the three filters to taste. It might help to bypass the filters on the top two Thors. Adjust the bottom filter, then turn the middle filter on, adjust it, and then finally turn the top Thor filter on and adjust it. That’s all there is to it. 3 filters affecting one sound source.
Routing Thor filters in series to affect a sound source

Routing Thor filters in series to affect a sound source

Example of the Filters in Series:

Audio Filtering separate Drums through Thor:

All of the above is fine and dandy, but what if you don’t want all the Drums filtered the same way. Let’s say, for example, you want the Bass Drum to be filtered by a Low Pass Ladder filter and the High Hat to be filtered through a High Pass in a State Variable filter. Well, without getting too complicated, here’s what you do:

  1. Follow the steps to create a Basic Thor Filter above.
  2. Create a Line Mixer 6:2 and move it to the top of the Devices in the Combinator.
  3. Flip the Rack around, and delete the audio output cables from the Redrum.
  4. Duplicate the Thor device (so you now have two Thor devices under the Line Mixer.
  5. Move the Audio Outputs from the first Thor into the Master Audio Outputs of the Line Mixer.
  6. Cable the Bass Drum Audio Outputs from the Redrum to the first Thor’s Audio Inputs 1 + 2
  7. Cable the High Hat Drum Audio Outputs from the Redrum to the second Thor’s Audio Inputs 1 + 2
  8. Cable the Audio Outputs from the two Thors into Channels 1 & 2 on the Line Mixer.
  9. Routing two separate filters to control the Bass and High Hat Drums

    Routing two separate filters to control the Bass and High Hat Drums

  10. Cable the other Drums into the free channels on the Line Mixer.
  11. Routing all the drums to the Line Mixer

    Routing all the drums to the Line Mixer

  12. Flip the Rack around again to the front, and then insert the Filters of your choice into the Filter 3 slots of both Thors. Adjust them to taste in order to affect the Bass and High Hat Drums

Example of separately filtered Drums (with a little delay on the High Hat):

Some Final Thoughts:

Finally, just because you filter one sound through the Global section of Thor, this doesn’t mean you can’t use the Thor to generate a sound of its own. This way, you end up merging two sounds together in a kind of layering. If you want to see how this is done, look at the “Synth+Filter – Droid Chatter” Combinator in the example files. You can do some pretty interesting things this way. Additionally, you can take one sound source, split it into two different Thor filters and then route them to two separate channels in the mixer, or back into one channel if you like. A wealth of options and possibilities, for sure. 

Example of a Synth Arp + Thor with an Analog Oscillator, both generating sound. The Synth Arp is being filtered through Thor while Thor is generating a sound of it’s own. This creates a layered effect:

So as you can see, routing audio through Thor is not difficult, but most people miss the step about the Modulation Bus Routing Section. If you remember to reroute the audio signal, you’re golden. That’s it in a nutshell. nothing fancy.

I mainly use Thor’s comb or Low Pass Ladder filter to affect drums and then put it all in a combinator. But that’s just one way you can use Thor.  Are there any other ways you Route your audio through Thor? Do you have some creative ideas that I haven’t covered here? Please share them. I’m curious to see how people are using Thor to affect external sources.

Download the Example Files

  18 Responses to “3 – Filtering Audio through Thor”

  1. Exactly what does the scale in the modulation bus routing section affect? When assigned 2 the buttons?

  2. Thanks it was clear and helpfull, i’ll follow all your posts

  3. @Marco,
    I’m sorry about the embedded player. That’s why I stopped using it after about 10 posts. I use soundcloud now, which is much more stable across all browsers and platforms. I AM glad that it worked for you after though. And I think if you try a different browser, that might have helped. But hopefully you don’t have that problem again. I appreciate you reading through though, and I hope you found the articles useful. All my best. Rob

  4. I have a problem with the embedded audio player on my site – I am unable to stop the tracks manually once started. They either play until finished, or in some cases they repeat indefinitely.

    Also, when I’ve seen this sort of thing on other sites, it’s usually set up so only one can play at a time. But since I can’t stop any of them, they just layer up and sound terrible.

    I left the page open and read through the article anyway. At the end, I went back and found all the ‘pause’ buttons now work. Not sure what’s going on here.

  5. Mangling is what it’s all about. Experiment, experiment, and experiment some more. :-)

  6. Thanks a whole lot for this.. I will be mangling my crate-digging finds through the Thor for a good long while!! I’m gonna investigate Thor a whole lot more now!! Thanks again!

  7. Meow,
    I have run into this problem as well. The problem is with the player that I use, and since it’s put together by a third party, I don’t have as much control over it as I would like. The only thing I can recommend is to try it in a different browser. I’ve found that IE7/8 and Google Chrome respond well to it.

    Another workaround might be to reload the page each time you play a soundbite. Not a great workaround, I know. But it will force the player to stop and reload everything.

    Third, I would offer that you may not need to play these files at all, since all the sounds are included in the Combinators that are in the reason (.rns) download at the bottom of the page. If you download the file and open it in Reason, you’ll have access to all the sounds that are provided in the tutorial. This might save you a bit of time, as you can preview them all separately to your heart’s content once they are on your system. And you’ll have all the Combi setups saved.

    If I can find a better player for the site, I will install it and use it instead. I’m sorry for the quirkiness of the player.

    I hope that helps.

  8. Good article.

    I seem to have a problem with the embedded audio player on this site – I am unable to stop the tracks manually once started. They either play until finished, or in some cases they repeat indefinitely.

    Also, when I’ve seen this sort of thing on other sites, it’s usually set up so only one can play at a time. But since I can’t stop any of them, they just layer up and sound terrible.

    I left the page open and read through the article anyway. At the end, I went back and found all the ‘pause’ buttons now work. Not sure what’s going on here.

  9. Glad to help man… I’ll try to keep coming back here as often as I can, but a few reminders on the PUF and my EditEd4TV FB page will remind me.

  10. Thanks Ed. Sometimes thinking things through with more than one brain helps. I’m sure you feel like a giant looking down at us ants most times. But as always, we need you giants to point out what’s obvious (to you) in order to make it obvious to us. But now that you explain it I can see how much sense this makes.

  11. Well, if the step sequencer is set for 1 step only, and the gate length is 100%, it is essentially a tied gate. Gate length of 50% is like a 1/2 note, 25% is a 1/4 note, etc. It remains a full note length though, with the balancing rest (for lack of a better term) due to the step duration remaining “1”. So just 1 step, 100% gate length = everything is stuck open. :)

  12. Yup yup. This makes perfect sense to me. I’ll probably add in a new combinator setup or two inside the downloadable file for this post to show these kinds of setups. . . when I have some time. I understand about keeping the gate length set to 100%, but I would also imagine it would need to be a tied gate step as well, correct?

    Again, thanks for all your help Ed. It is very much appreciated!

  13. Yup, that would do it. Though you should set the step sequencer for 1 step, then set the gate length of that 1 step to 100%. When you start the step sequencer it’s holding the gate open, so you can use filters 1 and 2 and 3. BUT, filters 1 and 2 are monophonic, so it all enters the amp section monophonically – bummer.

    Also note that filter 1, post-shaper, can go directly to the amp, or you can route it through filter 2. If you do go through filter 2, don’t forget to then activate filter 2’s routing button to feed it through to the amp section. It’s the magic of the routing buttons between filter 1’s shaper and filter 2.

  14. Ed,
    I actually thought of something like this. So, if I set up a matrix with 1 step to trigger the Thor continually, and then routed the audio through Thor’s “Filter 1” slot, would it then go through all the normal audio routing to Filter 2, and then through the amp and on out to the global section? That seems almost too easy. So basically you could use all three filters in a single Thor, and all the other parameters as well. Correct?

  15. Very cool Rob, great job. Another thing you can do with audio inputs into Thor is set the amount value to -100 (instead of +100). This inverts the signal 180 degrees out of phase. I won’t go into technical details, but there are some cool things you can do with mixing things out of phase. Also, people should know that the “Global” section of Thor (the bronze section on the right 1/3 of the programmer panel) is always active and on, which is why we typically route audio to filter 3 instead of filter 1 and 2. You can route audio to filters 1 or 2 but you’ll need a way to trigger Thor and open it up to process that incoming audio through the entire “post-oscillator” signal path of Thor (basically, filter 1, then the shaper, then filter 2, the amp, then filter 3, then the effects. There’s also the envelopes, but… oy… the possibilities are wide open.

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