I was not the greatest math student growing up. Math was always intimidating and I often got poor grades. Once I got into synthesis, I realized with a quickness that I was going to have to overcome some of that insecurity. There is no better way than to make synths. The desire outweighed the fear, and away I went.
With a little simple math in Reaktor, we can achieve some pretty useful results. As we saw in the MPVHub article I wrote about harmonics, we were able to use some math modules to get the harmonic series. In this article, we are going to use only a singe math module: Multiply.
We will navigate a drum loop using two knobs that determine the Sample Start time, Loop Start Value, and Loop Length Value.
Start with a new ensemble (File > New Ensemble) and open Structure view of the Default instrument.
Using Control-Click > Built-in Modules, create the following within the default instrument:
- MIDI In > Notepitch
- MIDI In > Gate
- Sampler > Sampler Loop
Control-Click, and select Built-In Modules > Math > Multiply
Control-Click on an input port of the Multiply Module, and create a control.
Control-click on the control attached to the Multiply module and select Properties. In the functions tab, give it the following values:
- Max = 1
- Min = 0
- Num Steps =
- Mouse Resolution = 12
Also, name it ‘Start’
Shift-select both the Multiply Module and his Control. Use Edit > Copy and Edit > Paste to create another control and multiply set. Rename the new control ‘Length’.
Make the following attachments:
- Attach the Notepitch Module to the Sampler Loop Module’s ‘P’ input
- Attach the Gate Module to both ‘G’ and ‘A’ ports of the Sampler Loop Module
- Attach the output of the Multiply Module attached to ‘Start’ to both the LS, and St ports of the Sampler Loop Module
- Attach the output of the Multiply Module attached to ‘Length’ to the LL input of the Sampler Loop Module
- Attach the Sampler Loop outputs to the voice combiners attached to the ‘L’ and ‘R’ output ports
Attach the ‘Len’ output of the Sampler Loop to the inputs of both the ‘Start’ Multiply and ‘Length’ Multiply Modules:
This output from the Sampler Loop is transmitting the length of the sample loop we have loaded in. Let’s think of the ramifications:
When the start knob value is multiplied by the length value from the sampler loop, we will be starting at a fraction of the loop’s length.
For example: if the length value coming from the sampler module is, say, 145986 milliseconds, that value is multiplied by the length control module’s value of .5, (The knob is halfway up), we start right smack in the middle.
Of course, we need a sample map!
Load the map provided with this article into the Sampler Loop Module. This is achived by opening the ‘View > Show Map Editor’ and choosing ‘Edit > Load Map’. The file is called HUB_015-map.
Now go to the panel, select the wrench tool to organize the knobs and sampler so you can see them easily. Deactivate the wrench tool and play a MIDI note value around C3. We can now navigate around the sample loop in varying increments that make musical sense!
Try experimenting with the values of the controls. You can use higher numbers to help create stutter effects and drum repeats!
Download the accompanying file here: