Institute for Computer Music and Sound Technology / (ICST) Zurich University of the Arts

Step-by-Step Setup Guide for the ICST AmbiPlugins in Reaper

Prerequisites

Before we begin, make sure you have Reaper, the ICST Ambisonics plugins and any recommended 3rd party pluginsinstalled.

Creating a Reaper template

We will create the template step by step from top to bottom.

1. Prepare Reaper

1. Open a new, empty Reaper session.
2. Create a new track (double click or use the menu).
3. Name the track Decoder and remove the master bus.

[!Tip:] Create all tracks with 64 channels by default and keep an eye on the routing.

2. Set up decoder routing

• Decoder routing for an Oktagon setup:
• Inputs: 64 channels from the “Bformat Master Track”
• outputs: 8 channels to the audio interface

1. ICST AmbiPlugins Decoder in the FX window.
2. open the AmbiDecoder
3. Select a speaker preset (e.g. Oktagon).
4. Customize AmbiDecoder settings:

• Ambisonics Weighting
• Ambisonics Order (1st to 7th order) 5. Run speaker test:
  • press the “Speaker Test” button or test individual speakers.

[!Attention:]  Keep an eye on the volume level!

9. Create the ‘Bformat-Master track’

3. Create a Bformat master track

• The Bformat master track receives all signals from:
• Ambience Encoders
• BFormat SFX
• BFormat players
• Since this is the master track, the final B format is recorded or bounced here.
• This track is colored red.
• It leads both to the AmbiDecoder and in parallel to a binaural track.

4. Create a Bformat player track

• Create a 64-channel track and route it into the Bformat master track.

[!Tip:] This allows B-format files from the 1st to the 7th order to be played.

5. Enable binaural listening

• Create a new 64-channel track and load a binaural plug-in (e.g. DearVR Ambi Micro.vst3).
• Move the track upwards.
• Route the output from the format master to this binaural decoder.
• Mute AmbiDecoder to hear only the binaurally decoded signal.

[!Tip:] Compare with Solo/Mute between AmbiDecoder and Binaural Decoder.

Example B shows a 5th-order b-format Ambisonic.

Now we can play back and listen to B-format files on eight speakers.

To be able to listen to the B format through headphones, we will now set up a binaural decoder:

• Create a new 64-channel track and load a binaural plugin of your choice into the FX window (e.g. DearVR Ambi Micro.vst3).
• Move the track to the beginning of the Reaper rack.
• Route the output of the Bformat master track to this binaural decoder (see GIF).

• Mute the AmbiDecoder to hear only the binaurally decoded signal.

[!Tip:] Compare solo/mute between AmbiDecoder and binaural decoder.

6. Mono Source & Ambisonics Encoder

• Create a new track Mono-Source and load a mono audio file.

Tip: Watch this Video

12. Mono AmbieEncoder overview.

• In the FX window, load the ICST MonoEncoder.

• Add a AmbiEncoder(ICST) (1-4) –> Mono-Encoder Routing:

• MonoEncoder → 64-channel output → Bformat master.

  

7. Record motions in the Reaper track

Record motions in the MonoEncoder:

Play back saved motion:

8. Using the Multi-Encoder

In the next example, I’ll demonstrate how we use the Multi-Encoder:

1. Insert the Multi-Encoder Track

   • Right-click in the empty Reaper track area and select “Insert Track from Template”.
   • Navigate to ICST AmbiPlugins and choose “ICST_AmbiEncoder_Multi_8src”.
   • This will open a Multi-Encoder with 8 mono sources, already routed into the encoder.

   2. Controlling Sources in the Multi-Encoder

   • If the routing is set up correctly, you can now control the placement and movement of up to 8 sources within the Multi-Encoder.

AmbiEncoder Settings

3. Understanding AmbiEncoder Settings**- The AmbiEncoder settings are crucial for your workflow. - The following GIF showcases the key AmbiEncoder features:

   

[!Tip: ] Watch the AmbiEncoder Video tutorial for more details.

4. ICST Distance Function
   • A unique feature of the ICST Ambisonics Encoder is its distance function, developed by Martin Neukom at ICST.
   • This function allows you to create various spatial configurations, simulating movement speeds from very fast to extremely slow. For in-depth instructions, refer to the Distance tutorial.

[!Tip:] If working with distance, define it at the start of your project to scale all XYZ coordinates correctly. _(Example: Distance scale from 0.0 to 1.0).

Recording & Editing Source Movements

5. Recording Movements in the Multi-Encoder

   • To understand how the Multi-Encoder works, let’s go through a recording example:

     • Set automation envelopes to “Write” mode.
     • Press Play (Spacebar) in Reaper and move Src_1 in the Multi-Encoder Radar.
     • Repeat the process for other sources.

     MultiEnc_01_write:

     Here’s an example with Src_3:

     

Here’s an example with Src_3:The next step demonstrates how to manually edit the xyz envelopes.

6. Manually Editing XYZ Envelopes

   • To refine movements, manually adjust the XYZ envelopes:
   • Hold Shift and click on the envelope to create a new edit point.
   • Move the point to adjust the XYZ coordinates.

7. Playing Back the Recorded Ambisonic Scene

Working with Groups

8. Creating a Group in the Multi-Encoder

   • In the Radar Display, select multiple Src points to form a group.
   • Assign a group name (e.g., G1).

9. Recording Group Movements

• Choose a recording mode:

  • “Latch” – Records only one source point.
  • “Touch” – Starts recording when a point is touched.
  • “Write” – Overwrites previous recordings.
  9. Playback & Evaluation
  • Listen to the final group movement recording via speakers (Decoder) or headphones (Binaural Decoder).

Finalizing & Exporting

11. Rendering the B-Format Master
    • Once satisfied, follow these steps to export the B-Format:
      • Select Bformat-Master Track and set it to Solo.
      • Open Menu > Render.

Render Settings:

1. Select Track (Stem Render) → Choose Bformat-Master.
2. File Name → Assign a B-Format filename.
3. Sample Rate → 48,000 kHz.
4. Channels → 64 (for 7th-order Ambisonics).
5. Multichannel Format → Set to Multichannel Files.
6. Large File Support → Use Wave/RF64.
7. Click “Render”.

Rendering-info: After the rendering process, you will get a Rendering Info window with the Peak and LUFS information.

8. That’s all, now you can drag and drop your B-Format onto the B-Format player track, set it to “Solo” and listen to the final result via the ICST decoder or the binaural decoder.

🎧 Happy ambisonics!

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