Step by Step Setup

Level: Beginner to Intermediate | Audience: Composer, technician, student, studio user.

Use this page when you want to build the ICST Ambisonics routing manually instead of starting only from a ready-made template.

Prerequisites

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

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.

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. Open ICST AmbiPlugins Decoder in the FX window.
2. Open the AmbiDecoder and select a speaker preset (e.g. Oktagon).
3. Customize AmbiDecoder settings:
   • Ambisonics weighting
   • Ambisonics order (1st to 7th order)
4. Run a speaker test:
   • Press the Speaker Test button or test individual speakers.

3. Create a Bformat master track

Create the Bformat Master track:

• This track receives signals from:
  • Ambience encoders
  • B-format SFX
  • B-format players
• This is the main recording/render point for the final B-format signal.
• Set the track color to red (recommended).
• Route it to the AmbiDecoder and in parallel to a binaural monitor track.

4. Create a Bformat player track

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

5. Enable binaural listening

• Create a new 64-channel track and load a binaural plugin (e.g. DearVR Ambi Micro.vst3).
• Move the track to the top of your Reaper project.
• Route the output of Bformat Master to this binaural track.
• Mute AmbiDecoder if you want to monitor only the binaural output.

Example below shows a 5th-order B-format Ambisonic file on the player track:

Now you can play and monitor B-format files on speakers or headphones.

Naming Convention (recommended)

Use stable names early to avoid routing mistakes:

• DECODER
• BFORMAT_MASTER
• BINAURAL_MONITOR
• SRC_01 … SRC_08
• MULTIENCODER_8SRC

6. Mono Source & Ambisonics Encoder

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

Video Tutorial: AmbiEncoder Setup

Mono AmbiEncoder overview:

• In the FX window, load the ICST MonoEncoder.
• Add an AmbiEncoder (ICST) (1-4) to the mono source.

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, we use the Multi-Encoder:

1. Insert the Multi-Encoder Track

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

   

2. Control Sources in the Multi-Encoder

   • If routing is correct, you can control the placement and movement of up to 8 sources.

AmbiEncoder Settings

3. Understanding AmbiEncoder settings

• AmbiEncoder settings are central to the workflow.
• The GIF below shows key AmbiEncoder features:

4. ICST Distance Function

• A unique feature of the ICST Ambisonics Encoder is its distance function, developed by Martin Neukom at ICST.
• This function enables different spatial configurations, from very fast to very slow movement behavior.

For in-depth instructions, refer to the Distance tutorial.

Recording & Editing Source Movements

5. Recording Movements in the Multi-Encoder

To understand Multi-Encoder behavior, run this recording example:

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

Example with Src_3:

6. Manually Editing XYZ Envelopes

• To refine motion, edit XYZ envelopes manually.
• Hold Shift and click an envelope to create a new edit point.
• Move the point to adjust 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 after touching a source
  • Touch: records only while touching
  • Write: overwrites existing automation

10. Playback & Evaluation

• Listen to the final group movement via speakers (Decoder) or headphones (Binaural Decoder).

Finalizing & Exporting

For a compact dedicated rendering guide, see Render B-Format in REAPER.

Pre-Render Checklist

Before rendering, confirm:

• Bformat Master is soloed
• Ambisonics format/order matches your target pipeline
• No unintended limiter/compressor on the master path
• Filename contains order and take (example: scene01_O5_take03.wav)

11. Rendering the Bformat Master

Once satisfied, 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 Hz.
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 rendering, Reaper shows a Rendering Info window with peak and LUFS values.

12. Drag and drop the rendered B-format file onto the Bformat player track, set it to Solo, and verify playback through the ICST decoder or binaural decoder.

Troubleshooting (Quick)

• No movement playback: check automation lane visibility and write/touch/latch mode.
• No decoder output: verify send from Bformat Master to Decoder input.
• Wrong speaker localization: run speaker test again and verify hardware output mapping.
• Binaural only / no speakers: check mute/solo state between Decoder and Binaural track.