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For Sample Creators: How to use the Wavefolder and Waveshaper effects

Oscilloscope view of a sawtooth wave form that has been folding back on itself.

Decent Sampler v1.7.3 introduces the new wave folder and wave shaper effects. These can be used to add extra harmonic content to your signals (aka distortion). What both of these effects have in common is that they usually sound much better when applied to a single voice rather than to an entire signal. In Decent Sampler, it is possible to apply effects at the voice level by attaching them to groups. Since each group is triggered independently, they do not share effects. In other words, each time you hit a key, a new copy of that voice will be created.

Wave folder

The wave_folder effect allows you to fold a waveform back on itself. This is very useful for generating additional harmonic content. Here is what that looks like in practice:

Oscilloscope view of a sawtooth wave form before wavefolding
Sawtooth waveform before wavefolding
Oscilloscope view of a sawtooth wave form after wavefolding
The same sawtooth wave form after wavefolding

These are the parameters that can be controlled:

AttributeTypeValid RangeDefault
typeRequiredMust be wave_folderwave_folder
driveOptionalThe volume of the input signal1 – 100, where 100 means the signal is amplified by a factor of 100 and 1 means no amplification is applied1
thresholdOptionalThe amplitude above which wave folding should take place0 – 10.00.25
Wavefolder parameters

Because wave folding tends to sound better when applied on a per-voice basis, it usually makes sense to set up the wave folder at the group level (separate group effects get created for each keypress). Example:

<?xml version="1.0" encoding="UTF-8"?>
<DecentSampler pluginVersion="1">
  <ui>
    <tab>
      <labeled-knob x="180" y="40" label="Drive" type="float" minValue="1" maxValue="100" textColor="FF000000" value="1">
        <binding type="effect" level="group" groupIndex="0" effectIndex="1" parameter="FX_DRIVE" translation="linear" />
      </labeled-knob>
      <labeled-knob x="280" y="40" label="Threshold" type="float" minValue="0" maxValue="1" value="1" textColor="FF000000">
        <binding type="effect" level="group" groupIndex="0" effectIndex="1" parameter="FX_THRESHOLD" translation="linear" />
      </labeled-knob>
    </tab>
  </ui>
  <groups>
    <group>
      <!-- samples go here -->
      <effects>
        <effect type="lowpass_4pl" resonance="1" frequency="500" />
        <effect type="wave_folder" drive="1" threshold="1" />
      </effects>
    </group>
  </groups>
  
</DecentSampler>
Code language: HTML, XML (xml)

Waveshaper

The wave_shaper effect allows you to apply standard tanh waveshaping to your input signal. Here are some examples what that looks like in practice:

An oscilloscope display of an example of sine wave before wave shaping is applied.
A sine wave before wave shaping is applied
An oscilloscope display of a sine wave after wave shaping is applied.
A sine wave after wave shaping is applied

There are a few parameters which can be controlled:

AttributeTypeValid RangeDefault
typeRequiredMust be wave_shaperwave_folder
driveOptionalThe amount of distortion. This really just controls the volume of the input signal.1 to 1000 where 1 means no change to the input signal and 1000 means the amplitude is multiplied by a factor of 1000.1
driveBoostOptionalChanges the character of distortion that gets produced0 – 1.00
outputLevelOptionalThe linear output level of the signal0 – 1.00.1
Waveshaper parameters

Because wave shaping tends to sound better when applied on a per-voice basis, it usually makes sense to set up the wave shaper at the group level (separate group effects get created for each keypress). Example:

<DecentSampler pluginVersion="1">
  <ui>
    <tab>
      <labeled-knob x="180" y="40" label="Drive" type="float" minValue="0" maxValue="1000" textColor="FF000000" value="0.5473124980926514">
        <binding type="effect" level="group" groupIndex="0" effectIndex="0" parameter="FX_DRIVE" translation="linear"/>
      </labeled-knob>
      <labeled-knob x="280" y="40" label="Boost" type="float" minValue="0" maxValue="1" value="0.328312486410141" textColor="FF000000">
        <binding type="effect" level="group" groupIndex="0" effectIndex="0" parameter="FX_DRIVE_BOOST" translation="linear"/>
      </labeled-knob>
      <labeled-knob x="380" y="40" label="Output Lvl" type="float" minValue="0" maxValue="1" value="0.1" textColor="FF000000">
        <binding type="effect" level="group" groupIndex="0" effectIndex="0" parameter="FX_OUTPUT_LEVEL" translation="linear"/>
      </labeled-knob>
    </tab>
  </ui>
  <groups>
    <group>
        <em><!-- Samples go here. --></em>
      <effects>
        <effect type="wave_shaper" drive="0.5473124980926514" driveBoost="0.328312486410141" outputLevel="0.1"/>
      </effects>
    </group>
  </groups>
Code language: HTML, XML (xml)

Examples

The examples from this blog post can be download here.

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For Sample Creators: How to use Convolution in your Decent Sampler presets

A spectrogram of a convolution reverb impulse response.

Version 1.6.12 of Decent Sampler brings a Convolution effect to the Decent Sampler platform. If you don’t know what Convolution is, you can see a great explanation here. The most common use case for convolution is in creating reverb, and that is the use case that will be demonstrated here.

How to add the Convolution effect to a preset

The convolution effect is invoked in much the same way that any other effect is defined:

<effects>
  <effect type="convolution" mix="0.5" irFile="Samples/Hall_IR.wav" />
</effects>Code language: HTML, XML (xml)

As you can see, other than the required type attribute, there are two other attributes:

  • The mix attribute controls how much of the convolved signal is present in the output. A value of 0 is completely dry whereas a value of 1 is completely wet containing only the convolved signal.
  • The irFile attribute specifies the file that should be used as an impulse response or IR.

How to control the convolution effect using UI controls

Two of the convolution effect’s attributes can be controlled using UI controls. The mix level can be controlled by a knob as follows:

<labeled-knob x="680" y="40" label="Conv Mix" type="float" minValue="0" maxValue="1" value="0.5" textColor="FF000000" >
  <binding type="effect" level="instrument" position="0" parameter="FX_MIX" translation="linear"  />
</labeled-knob>Code language: HTML, XML (xml)

The IR impulse can be changed dynamically using a menu control:

<label text="IR File" x="480" y="40" width="120" height="30"></label>
<menu x="580" y="40"  width="120" height="30" requireSelection="true" placeholderText="Choose..." value="1">
  <option name="long hall.wav">
    <binding type="effect" level="instrument" position="1" parameter="FX_IR_FILE" translation="fixed_value" translationValue="Samples/long hall.wav" />
  </option>
  <option name="ABLCR Chord Vocal.aif">
   <binding type="effect" level="instrument" position="1" parameter="FX_IR_FILE" translation="fixed_value" translationValue="Samples/ABLCR Chord Vocal.aif" />
  </option>
  <option name="Amp Spring High.aif">
    <binding type="effect" level="instrument" position="1" parameter="FX_IR_FILE" translation="fixed_value" translationValue="Samples/Amp Spring High.aif" />
  </option>
  <option name="Swede Plate 3.5s.aif">
    <binding type="effect" level="instrument" position="1" parameter="FX_IR_FILE" translation="fixed_value" translationValue="Samples/Swede Plate 3.5s.aif" />
  </option>
</menu>Code language: HTML, XML (xml)

Examples

An example Decent Sampler preset that uses IR reverb can be downloaded here.

Performance considerations

While convolution is a powerful tool that can go a long way towards shaping a sample library’s sound, it can also be quite costly in terms of CPU usage. Sample creators would do well to create versions both with and without convolution effect and compare the relative CPU usage of the two versions before opting to use convolution.

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Kontakt Video Tutorial: How To Remove Unwanted Frequencies + FREE Kontakt Library

Have you ever had an audio file that contained a bunch of extra frequencies in it that you wish you could just remove? Spectral editing may be for you. In this video, I show how to use spectral editing to clean up a sample so that I can make a Kontakt instrument–but not just any instrument:

A few weeks ago, Christian Henson announced a competition: he challenged the internet community to try to turn two oddball samples he’d recorded into true sample-based instruments.

So this video serves two purposes: it’s both a quick introduction to spectral editing as well as my entry into Christian Henson’s Rusty Gate sample competition.

Here’s a link to the free sample (Kontakt 5.3 or higher).

Here’s a link to Christian Henson’s Rusty Gate Sample Competition.

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New sample library: Melodica!

The melodica is a free-reed instrument that became popular in the 1950s. We’ve sampled it twice and turned it into a Kontakt instrument.

Buy it here: https://www.decentsamples.com/product/melodica-kontakt/

Features:

  • Compatible with the full version of Native Instruments Kontakt 5.3.1 (or later)
  • Two sample sets: Melodica I (4 round robins, 2 velocity layers) and Melodica II (4 round robins, 1 velocity layer)
  • Voice controls allow you to choose between 1, 2, and 4 voices simutaneously
  • ADSR controls
  • EQ controls
  • Custom convolution reverb with reverb level knob
  • Chorus level knob
  • Two versions of each instrument are included: 1) velocity controls dynamics; and 2) modwheel controls dynamics.
  • Sample rate: 24-bit 48khz
  • Library size: 148MB
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Present in the Box Cello Kontakt Library

In December 2018, Dave Hilowitz built a fully playable cello out of an old silverware box. We spent the month of January sampling the instrument and have no turned it into a feature-packed Kontakt library. Introductory price: $20!

Buy it here: https://www.decentsamples.com/product/box-cello-kontakt/

Features:

  • Three articulations: sustain (both velocity and modwheel), spiccato and pizzicato
  • Up to 8 round robins per note, 2 velocity layers for a maximum total of 16 different samples per note!
  • ADSR controls on all patches (except spiccato)
  • EQ controls on all patches
  • Recorded with three different mics (including a piezo contact mic). Mic levels are controllable after the fact to give maximum sonic flexibility
  • Three experimental patches: Texture I, Open Strings, Open Strings (Ensemble)
  • Requires the full version of Kontakt 5.3.1 or later.
  • Library size: 1.03GB (each articulation is separate patch so you can easily get rid of articulations you don’t need if you find yourself short on disk space)
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Video Tutorial: How to Make Release Triggers + FREE Tea Kettle Whistle Kontakt Library

In this video, I show how to make release triggers in Kontakt. In the process, I create a full-featured Kontakt library out of the whistle from a Chantal tea kettle.

The instrument that I make in the video can be downloaded for free here.

– Dave

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Video Tutorial: How to Make Mic Level Controls in Kontakt + FREE BOWED NAGOYA HARP SAMPLE

In this video, I find out what happens when you play a Japanese Nagoya Harp (Taishogoto) with a violin bow! In the process, I demonstrate how to make microphone volume level control knobs.

The Plucked Nagoya Harp Library (with 3 mics, velocity layers, round robins, etc.) is still available for $10 here.

The completely different but related Bowed Nagoya Harp Kontakt Library that I created in this video is available for FREE here.

Enjoy!

– Dave