A few days ago I posted a two-step tutorial on how to convert ambisonics recordings from A-format to B-format. The second tutorial was posted a few days after I figured it out, and I had already managed to forget some of the details, and got it all wrong.
In the mean time I have hit into further problems in Logic if using a sound card that doesn’t support the sample rate of the original A-format recordings. And, I have figured out that it is much easier and faster to do in Wave Editor. So, here’s a new and improved tutorial.
We start out where tutorial 1 ended: The de-interleaved files have been assembled into one 4-channel A-format sound file.
Open the interleaved 4-channel A-format file in Wave Editor:
Select the layer in the Layer sidebar, and add the SoundField SPS200 SurroundZone AudioUnit plugin:
Adjust the plug-in settings to appropriate values:
- Output should be B-format
- Depending on how the mic was positioned during the recording, you might need to activate the Invert and End Fire settings
Select the layer in the Layer sidebar, and choose Layers > Flatten Layer from the menu bar. You’ll need to adjust a few settings:
- Set number of channels to 6
- Check the Latency compensation toggle
- Set destination to new document
Hit OK and have a coffee while it is rendering.
After a while the new document will open. You’ll see it having 6 channels, but channel 3 and 4 contains nothing but silence. In the screenshot below I have changed the color of the layer to distinguish it from the old document:
Select all of the silent channels (3 and 4) by double-clicking them, and remove them using Channels > Remove channels from the menu bar:
You are left with a 4-channel B-format sound file. Save this wherever you want to, and you are done.
