REAKTOR PART 3
1. Introduction
This week we’re going to continue on our journey into building different types of Instrument in Reaktor. As you’ve already seen Reaktor is capable of producing a wide range of synthesis and the library is stacked full of Ensembles that can give you any type of sound you want.
So why look at building them? Well, on one level it can give you a greater understanding of how different types of synthesis can be implemented which can definitely help in ‘visualising’ the kinds of sound you want to create. Secondly it’s actually a lot of fun!
You will have seen last week, that Reaktor provides a collection of pre-built components, called Macros that can take the pain out of building but this week I want to delve a little deeper. The basic building blocks of a Reaktor build are called Built-in Modules and they will provide us with everything we need to build some pretty sophisticated Instruments from the ground up. So, roll up your sleeves and lets get stuck in.
2. Building a basic Additive Synthesiser
The science behind Additive Synthesis has been with us for a very long time. The technique is based on work done by a French mathematician and physicist called Joseph Fourier who died in 1830. According to Fourier any periodic (repeating) waveform, no matter how complex, can be broken down into a successive series of sine waves; this process is known as Fourier analysis. What’s even more amazing about this is that Fourier’s research is based on much earlier work dating back to the 3rd century BC!
If this process can be used to separate out complex waveforms into much simpler ones, then what about the other way around? Can you build complex waveforms out of sine waves of different periods? Well the answer is a resounding yes, in the form of Fourier Synthesis. The idea here is that you can take sine waves of different frequencies, add them together and get new sounds. If you remember back to week 1, we looked at something very similar in the form of the harmonic series. Each harmonic in the series is actually a sine wave of a different but harmonically related frequency, what we can now see is that it is theoretically possible to build a square wave (for example) out of a bunch of sine waves!
Whilst the mathematics of this is beyond the scope of this course, Reaktor can give us an insight into how it’s done, and even has a built-in module for this very purpose, the Sine x4 Oscillator.
Essentially the Sine X4 Oscillator comprises of four sine oscillators with sine waveforms. Each sine oscillator has an associated Frequency and Amplitude input that can be accessed through the ports labelled F1 through F4 and A1 through A4 respectively and the fundamental pitch is controlled with a signal at the P input port.
The output ports labelled S1 through S4 each generate a single harmonic at the frequency of that oscillator (F1 at S1 and so on).
Now, here’s the cool thing. If we fix integer
constants, starting with 1, at the Frequency inputs
we can generate different harmonics in the harmonic series for the fundamental at the P input. This means that we can output the 1st Harmonic at S1, the 2nd Harmonic at S2, the 3rd Harmonic at S3 and the 4th Harmonic at S4.
The OUT port on the right hand side gives us the sum of Ports S1 – S4, so if we connect this up to output terminals so we can hear it, we will hear the sum of Ports 1 – 4, we now have Additive Synthesis!
Finally, we can connect faders to the Amplitude input ports, which will give us volume control over the individual harmonics widening out the tonal range of our synth.
The Build
For the purposes of our Additive Synth, one Sine x4 Oscillator will not be enough to give a fine range of tonal control, so we’re going to duplicate the first. We’re also going to add some visual displays so we can see what’s going on.
The following steps will take you through the process from scratch:
- File>New Ensemble. Make sure you can see the Structure View and Panel View simultaneously
- You might see an Instrument already loaded but if not you’ll need to create one. Right Click > Insert Instrument > _New-1in-1out then connect both outputs of the new Instrument to the Audio Out Channels 1+2 of the Ensemble.
- 3.RightClick>InsertInstrument>Master
- 4.RightClick>InsertInstrument>Analysers&Displays>Spektrum
and connect the out from your new instrument to the inlet of Spektrum
- 5.Set voices to 1 on your instrument panel then double click the Instrument Icon in the structure.
- 6.RightClick>Built-inModule>Oscillator>Sine x4 and connect the Out to both the Audio voice combiners which look like this: }
To trigger this oscillator using a MIDI keyboard, we’ll need to add a NotePitch module and connect it to the P inlet of the Multi-Sine
- RightClick>Built-inModule>MIDIIn>Note Pitch and connect it to the P inlet of the Multi-Sine
- Right Click on F1 & then A1 inlet and choose Create control.
- Double click on F1 and set Minto 1, then click on the A1 knob and open Properties > Appearance tab. Set type to “Vertical Fader”
- Unlock the Panel and arrange A1 below F1
- To duplicate them select both, by highlighting one, then shift clicking on the other, then Command + D/ Ctrl + D or Right Click and choose Duplicate
- Select over all 4 controls and duplicate again. Arrange and connect up appropriately.
- Label each control according to the inlet they’re connected to.
14. Right Click > Macros> Building Blocks > Displays > Micro Scope and connect the Out of the Audio voice combiners into the Micro Scope
15. Turn down all sliders except A1
16. Press a note on your MIDI keyboard and then rotate F1 and you’ll hear it stepping through different numbered harmonics. These are known as the harmonic series
17. Next, set F1= 1, F2 = 2, F3 = 3, F4 = 4 and then vary the different levels and listen how it affects the timbre of the sound.
Using only 4 harmonics doesn’t give us a great deal of control, so to create an 8 harmonic additive synth we’ll need to duplicate our current patch.
18. Select over the Multi-Sine & its controls in the structure and duplicate 19. Click on the duplicated Multi-sine and drag it with the controls to the
space below.
20. Delete all the F controls and then right click on each inlet and choose Create Constant
21. Set the 2nd to 2, 3rd to 3 etc all the way to 8. Unlock and tidy up the panel if needed.
22. Right Click > Built-in Module > Signal Path> Amp/Mixer and connect the outlet of one Multi-Sine into the inlet,
23. Drag a cable from the Out of the other Multi-Sine and then whilst holding down the command key (or ctrl key on PC) connect it into the inlet which magically appears on the mixer module.
At the moment the sound is constant, so to turn the note off when you press your MIDI keyboard, we will use the Gate module.
24. Right Click > Built-in Module > MIDI In> Gate
25. Right Click >Built-in Module > Math > Multiply and connect the out of the
Gate into an inlet on the Multiply module
26. Connect the out from the Mixer to the other inlet on the Multiply module
27. Connect the out from the Multiply module to the inlet of the Audio Voice Combiner.
3. Building an FM Synthesiser
We’ve already looked at FM synthesis in a lot of depth previously in the course but how about building one of your own? Once again, Reaktor’s built-in modules give us the perfect starting place for out very own FM synthesiser
To recap, simple FM synthesis occurs when the frequency of one oscillator (carrier) is modulated by the frequency of another oscillator (modulator).
The Modulator oscillator modulates the carrier’s frequency up and down, by an amount specified by the Modulation Amount and at a rate controlled by the Modulator’s frequency. Check out the diagram below and see how the Carrier Frequency is controlled by the output of the Modulator.
When the modulation frequency is above 15Hz, sidebands are created. These are additional frequencies not present in both oscillators and are created due to the effect of modulation.
The more the carrier frequency is modulated, the more sidebands are created and the brighter the sound. You can see in the 4 spectrum analysis below, how the modulation amount increases the complexity of the sound. Remember all these additional harmonics you can see, are produced by the effect of one oscillator modulating the frequency of another – so only 2 oscillators are creating all these frequencies.
As we’ve seen, FM synthesis as a synthesis method is quite complicated, as the resultant sound is heavily dependant on maths rather than a specific musical control. It’s common to find parameters such as Modulation Index and Harmonic ratio, but we’ll be concentrating on the key concepts and will control the carrier frequency and Modulation amount directly which will give you a better understanding.
Creating an FM Synth isn’t particularly easy using standard Reaktor oscillator modules as there is no direct access its frequency but there is an oscillator module that is perfect for the job- the Sine FM module.
As well as the standard Pitch and Amplitude ports there is an additional (F) that enables you to modulate the frequency of the output directly. This is the key to building our FM synth.
By connecting the Output of a second Sine FM module (the modulator) to the F input port of our first (the carrier) we can modulate the carrier frequency and create FM!
Lets get building….
1. Setup Reaktor as before with a New-2in2out instrument connected to a Spektrum + Master
2. Change number of voices on instrument panel to 1
3.Double Click the Instrument Icon to enter its structure and Right Click > Macros> Building Blocks > Displays > Micro Scope
4. Connect the Out of one of the Audio voice combiners into the Micro Scope
5. Right Click > Built-in Module > Oscillator > Sine FM
6. Connect the Sine FM Out to both the Audio voice combiners
7. Right Click/ the P, F (Frequency) and A inlet and choose Create Control. Unlock the panel, the controls and then lock the panel again.
8. Double Click on Pitch control and set Min to -100, also change the Num Steps to 227 – Now it behaves like a standard sine wave generator. When Pitch is -100, the Freq control produces the exact frequency it displays.
We’re now going to set up a second oscillator to modulate the frequency of the 1st.
9. Delete the Freq control
10. Duplicate the Sine FM plus its controls and drag to the left and as in
the diagram on the next page
11. Double click on the Sine FMs and label them Modulator and Carrier respectively.
12. Name the controls Mod Pitch (P) & Mod Amount (A), Carrier Pitch & Carrier Amount
13. Double click on Mod Amount and in Settings tab: Min = 0, Max = 5000 Num of steps = 100
14. To create a Coarse and fine control duplicate the Freq control
15. Right Click > Built-in Module > Math > Add
16. Connect both controls into the Add and its outlet into the F inlet of the modulator
17. Label one Coarse Freq and edit its Min: to 0 & Max: 5000 from Properties
18. Label other Fine Freq: Set Min: 0 & Max: 50 and Stepsize to 0.25 in Properties
19. Unlock and tidy the panel.
Have a play with the controls!
The Power of The Macro
Now that we have the basic FM synth built it’s time to look at supercharging the synth by using macros. The last time we were looking at macros we were pulling them ‘off the shelf’ to help simplify the build but this time we’re going to look at building an envelope from the ground up.
- RightClick>Macros>New1In_1out, double-click on the Macro symbol to enter it.
- RightClick>Built-inModule>LFO,Envelope>ADSR
- Right Click on each ADSR inlet and Create Control for each one.
- Right Click ADSR module in the structure and open Properties, click on the Appearance Tab, and check the Visible box
- Right Click > Built-in Module > Math> Multiply
- Connect the ADSR Envoutin to the Xmodule
- Right Click the other Inlet of the Xmodule and choose Create Control.
- Name it Amount & set the Max to 5000
- Connect the out of X to the Out terminal
- Connect the In terminal to the G inlet on the ADSR env.
- Name the In terminal: Gate
- Double Click on the background to exit up the instrument level.
- Rename the Macro to Envelope
Once you’ve created your Envelope you can save the Envelope into your User library by right-clicking on and selecting ‘save macro’ this will be available to use in any Reaktor instrument you want.
Now we need to connect up the envelopes.
- Duplicate the envelope macro twice(command/ctrl+D),then name them Pitch Mod Env, Mod Amt Env and Carrier Pitch Mod Env
- Connect the Pitch Mod Env Out into the+module,(Remember to hold command/ ctrl key to create a new inlet to the + module
- Connect the Mod Amt Env out in to the Ainlet of the modulator
- Delete the Modulation Amount control which was previously in the Ainlet
- Connect the Carrier Pitch Mod Env Out into the + module which is connected to the carrier, (Remember to hold command/ ctrl key to create a new inlet to the + module
- RightClick>Built-InModule>MIDIIn>Gate
- Connect the Gate module to the 3 Gate inlets and the A inlet on the Carrier oscillator.
- Create constant for the Modulator P inlet and set to–100
So far so good then, but there is more that we can do. In FM terminology oscillators are known as Operators and the more we have the greater the sonic potential of the synth. The best way to create more is to make a self contained operator within a macro and then duplicate it a number of times. This is where the power of modular synthesis lies, as it becomes very quick and easy to expand your ideas. So the macro we’re going to create will have a couple of envelopes, as well as pitch and amount controls, which we’ll then duplicate.
- Select over the following modules-hold down shift and click on any extra modules you want to add, then select copy as normal
- Right Click and select Macro>New1In1Out
- Double click to open the macro and then paste the modules in
- Duplicate the In terminal twice
- Name the top two Pitch, Gate, the 3rd can just be called In
- Connect the Gate In terminal to Gate Ins on both Envelopes
- Connect the Into the+module(Remember to hold command/ctrl key to create a new inlet to the + module)
- RightClick>Built-In module>Panel>Switch
9. Create a constant for the switch inlet and set this to-100
10. Connect the Pitch In terminal to the switch by holding down command
11. Connect Out of the switch to P inlet on the modulator
12. Double click on the switch inlet names, and name Freq Mode for – 100, and Pitch Mode for the other.
13. Name your macro “Operator”
14. Tidy the panel.
15.Delete all the other modules and controls not including the Audio Voice combiners & out terminals
16. Duplicate the Operator macro twice (three overall)
17.Name them Operator 1, 2 & 3
18.Connect the Out of 1 to In of 2, Out of 2 to In of 3 and the Out of 3 to both audio voice combiners
19.Right click > Built-In Module > MIDI In > Note Pitch
20.Right click > Built-In Module > MIDI In > Gate
21.Connect both these up to the corresponding inlets on each operator and your structure should look something like this:
22.Tidy the panel
23.Rename the Mod Amt Env Macro on operator 3 to Amp Env
24. Within Operator 3 only, double Click on the Amount control and set Max to 1, and the Num Steps to 127
25.The synth should now be ready to create a range of awesome FM textures, so make sure you save your ensemble, then get making some shapshots!
4. Sampling in Reaktor
When we first started looking at Reaktor we saw how it’s possible to produce a vast array of sounds using the Ensembles in the factory library. Every flavour of synthesis is represented as well as a wide range of sample based Ensembles. In truth, Reaktor is capable of becoming an incredibly sophisticated sampler and has several built-in modules from the humble Sampler right through to the mind blowing Grain Cloud.
In this lesson we’re going to take a look at a couple of the sampler Modules available, the Sampler and the Sampler Loop.
Before we dive into building we need to look at how you can access and manage samples using Reaktor’s Sample Map. Every sampler module uses the Sample Map so it definitely makes sense to have a look at it now.
(The Sample Map Editor)
There are several ways to access the Sample Map Editor
Press the Sample Map Editor button on the toolbar- Goto View > Show Map Editor
- Press F9
- Right-click on a Sampler Module on the Instrument Panel and choose ‘Open Map Editor’
Through the sample map, you can add audio files (in aiff or Wav format) to your Sampler Module. You can add multiple audio files, which can be placed on individual keys or stacked on the same one for triggering multiple samples from one key.
The Sample Map Editor is split into two sections, the Sample List View on the left hand side and on the right, a window that can be switched between the Key mapping View and the Sample Waveform View.
Press the Sample Map Editor button on the toolbarSampler List View
The Sampler List View has different behaviour depending on whether Reaktor is in Play or Edit mode. In Play Mode only the Name and Location columns are visible so, to be honest, it’s best leaving Reaktor in Edit Mode.
In Edit Mode the Sample List View gives you an overview of all the samples used in the selected Sample Map, as well as giving you Sample Map editing options.
The visible columns display basic information for all the samples in the Sample Map. You should recognise the titles from your work with Kontakt, L & H refer to the Key range, LVel & HVel refer to velocity level.
The drop down list in the top left corner lets you switch between multiple sample modules if you have them in your Instrument. The structure button immediately to the right of the drop down list gives you immediate access to that particular module in the structure view
The Embed box allows you to save the selected sample (if checked) with the Ensemble otherwise it will be referenced from the hard drive.
To add audio files to the sample map you can use the Add button, which will open a window from where you can select them. Alternatively you can drag and drop from anywhere on your computer or from the Disk tab on the sidebar.
There are also options to Replace/Save As and Remove.
Finally, all of these options are available by Right-Clicking in the Sample List View
Keymapping View
Akin to the mapping editor in Kontakt 5, this view displays a virtual keyboard with the samples arranged in boxes above it. The samples can be moved and resized in the same way that Zones can in Kontakt and you can zoom in and out using the using the scroll bars and zoom buttons.
Two main things to note here are the Root value field, which sets the root note of the sample (the natural note of the sample) and the Tune value field which sets the tuning of the sample.
Waveform View
This is similar to a stripped down version of Kontakt’s Wave Editor and is accessed by clicking on the Waveform button. You have access to basic Loop controls (but not in ever Module), reversing and so forth on the selected sample and you also have the option of linking through to an External Wave Editor for more detailed editing
In my experience of this editor it’s best to do most of the sample editing that you need to do (like topping and tailing) before you bring the audio file in to the sample editor.
The Samper Module
The sampler module is the simplest sampler module available and can be considered as a ‘conventional’ sampler. As we’ve seen before, the Pitch input port can be connected to a Note Pitch Module, which sends a MIDI note to the input. In the case of the Sampler this is used to ‘look up’ a sample in the Sample Map telling it which sample should be played back and at which Pitch.
The Trig input port is used for triggering sample playback from the beginning of the sample.
To build the sampler, do the following
1. GotoFile>New Ensemble and go to the structure view
2. Delete the Input terminals and double click on the Instrument logo
3. Delete the Input terminals
4. Right Click>Built-InModule>Sampler>Sampler
5. Right Click>Built-InModule>MIDIIn>NotePitch
6. Right Click>Built-InModule>MidiInGate
7. Connect the Note Pitch module to the P input port of the Sampler
8. Connect the Gate module to the Trig input port of the the Sampler
9. Right Click on the A input Port and select Create Constant
The samples in the Sample Map respond to MIDI velocity as well as to MIDI note so in the example above the Amplitude has be set to 1 so that the amplitude is unaffected by velocity. An alternative method for using velocity with Amplitude is shown in the diagram below.
The Sampler Loop Module
Another ‘conventional’ sampler loop module but don’t dismiss it yet! The Sampler Loop module is used for the real time polyphonic and transposed playback of mono or stereo samples in Sample Maps or Wavetables. With this module you can build a range of samplers from a simple one-shot trigger to ones that allow looping of the sample and because all this is accessible from input ports you’ll be able to manipulate settings from the Panel!
You’ll notice that there are a fair few more input ports on
this module which we’ll get to in a moment for now I want you to focus on the output port Len.
What Len does is to report the length (in ms) of the currently selected sample. Now this may not seem like much but it allows you to know exactly where you are in the sample, which means you can manipulate it using other Reaktor modules. We’ll see an example of this in the build in a moment.
The input ports are as follows:
- G: Input port for the Gate signal
- P: Input port for controlling the playback rate at which the sample is played.
- Sel: Input port for selecting a sample from the sample map.
- F: Input port for modulating sample playback rate. If you connect this to another oscillator then frequency modulation can occur. Hit it with a large negative value and the sample will reverse!
- St: input port for start point of the sample.
- LS: This is loop start and is the input port for the start of the sample loop.
- LL: This is loop length and is the input port for the length of the sample.
- A: Input port for controlling playback amplitude
Let’s now take a look at building a sample loop player:
1. GotoFile>New Ensemble and go to the structure view
2. Delete the Input terminals and double click on the Instrument logo
3. Delete the Input terminals
4. RightClick>Built-InModule>Sampler>SamplerLoop
5. RightClick>Built-InModule>MIDIIn>NotePitch
6. RightClickBuilt-InModule>MidiInGate
7. Connect the Note Pitch module to the P input port of the Sampler
8. Connect the Gate module to the G input port of the Sampler.
9. Connect the Gate module to the A input port of the Sampler.
Next we’re going to set up the controls that give us access to Start. 10.Right Click > Built-In Module > Math > Multiply
11.Right Click > Built-In Module > Panel > Knob
12.Connect the Knob to the Multiply input port
13.Connect Len to the other Multiply input port 14.Connect the Multiply output port to the St input port 15.Rename Knob to ‘Start’
Now we’re going to create controls for Loop Start and Loop Length by using the duplicate command.
16. Select the Multiply Module and the Knob and hit command-D to duplicate.
17.Rename the duplicated knob to ‘Loop Start’
18.Connect the Multiply output to the LS input port
19.Select the Multiply Module and the Knob and hit command-D to duplicate.
20.Rename the duplicated knob to ‘Loop Length’
21.Connect the Multiply output to the LL input port
22. Tidy the Panel
5. Building a Ring Modulator Effect
Ring modulation is often called Amplitude Modulation, although this isn’t strictly correct they create pretty much the same effect, AM synthesis allows the original sound through, whereas with Ring modulation you only hear the sum and difference tones (exactly like the sidebands we saw in FM). They’re capable of some really interesting metallic textures, as well as the ability to sound like an old AM radio being tuned, hence the name!
In the diagram below you can see a block diagram of two oscillators, with one controlling the volume of the other, which is essentially all it is, albeit at a frequency within our hearing range. It’s quite common to use only one oscillator and then an external audio input, like a voice, and probably the most famous example of Ring Modulation is the sound of the daleks from Doctor Who.
To build a Ring Modulator in Reaktor we need to use a bit of math that we’ve already seen, namely, the Multiply Module to literally multiply the outputs of two different Oscillators.
Follow the steps below to build a ring modulator, which can be used for synthesis, processing samples or as a plugin.
- File>New Ensemble and double Click the Instrument to enter its structure.
- Right Click>BuiltInModule>Oscillator>Sine
- Right Click the P & A inlet and choose Create Control
- Select over the controls and the Sine module and Duplicate(Command + D)
- Delete one of the Amplitude controls and connect the other into the spare A inlet
- You’ll then need to tidy up the panel and the structure.
- Right Click>BuiltInModule>Math>Multiply.
- Connect the outs from the 2 Sines into the 2 inlets on the Multiply.
- Connect the out from the Multiply into the 2 Audio Voice Combiners
10. Right Click > Built In Module > Terminal > In Port
11. Connect one of the In Ports into one of the inlets on the Multiply module and delete the other one.
12. Delete the Sine and Pitch control which are no longer used 13.Double click in the Structure to return to the ensemble
14. Connect the out 1 from Audio Input into the In on your instrument 15. Now File > Save Ensemble> choose a location for the ensemble file.
Now we have a working Ring Modulator how about stepping it up a gear? Firstly a bypass switch would be useful and It would be more practical if it could process stereo audio files as well.
For the bypass:
16.Right click > Built-In Module > Panel > Switch
17.Connect the output of the switch to the audio voice combiner.
18.Connect the In Port to the Switch and label the Switch ‘Bypass’
19.Connect the output of the Multiply Module to the Switch by holding down CMD and dragging to the three small dots on the Switch.
20.Select the Switch go to Properties > View and check ‘1 Toggle Button’
21.In the same panel uncheck ‘Show Label’
22.Tidy the Panel.
Et Voila! We now have a working bypass switch. The next step is to turn the Instrument into a stereo one. In the process will we make use of a Reaktor property called Internal Connections. This can be found under the Connect tab of the properties page and it allows you to link module controls together. For example, we are going to link two switches together so that they perform as one. Once they are linked one of the switches can be hidden so you essentially have one switch for a stereo Instrument.
This should all make sense as we build.
23.Select the In Port, the Multiply Module, the Switch, the Audio Voice Combiner and the Out Port and Duplicate (CMD – D) and then tidy the structure and the Panel.
24.Rename the two In Ports, the top one to L and the bottom one to R
25.Rename the corresponding Out Ports the same
26.Select the top Switch, go to Properties > Connect > Internal Connections and click on the top button on the top right hand side.
27.Select the lower Switch, go to Properties > Connect > Internal Connections and click on the middle button on the right hand side.
28.On the Panel you should now be able to press the top Bypass button and select both at once.
29.Select the lower Switch, go to Properties > View > Visible and uncheck ‘On’
30.Now File > Save Ensemble> choose a location for the ensemble file. You should now have a stereo Ring Modulator with working Bypass!
