@woland Hello all. I am sorry I am ut of the forum at the moment. But Here is my take for the ambisonics in Isadora. I'll report much much more in the future because I believe this is one of the future of sound in real time applications, recorded sound and xr projects creations in Isadora.
In order to solve Simon problem we have to think in 4 stages
1) Recorded versus live
So, first of all, I have no experience in real time use of microphones in Isadora. I was able to conect a Zylia SM1 and a Zylia SM1S, third order ambisonics microphone in Isadora but for the moment I don't see a use case for it. It worked, but I'll dive into live later. My work is done solely on recorded sound at this moment, but I answer here for recorded sound. I hope it can help and I think it might.
A little bit of theory
You all probably know the rule of thumb to understant High Order Ambisonics (HOA). The higher the order the higher the number of micrphone capsules inside an ambisonic microphone and the higher is the spatial precision and lower signal to noise ratio.
The rule is the following : order +1 suqared
First order : (order 1) + 1 =2, squared = 4 : First oder (like Ambeo) is 4 capsules
Second order (order 2) +1 = 3, squared = 9 (minimum)
Thiurs order (order 3) +1 = 4, sqared = 16 (minimum)
etc.
2) A format versus B format
Now, the second thing to know (and maybe this is a part of the problem that Simon is having), is that the raw recording, called A format, is useless per se. A format is just used to transcode into B format in order to get to he spatial harmonics that can be really used to rotate pitch yaw and roll the rource and spatialize it.
Normally a microphone outputs just the A format. A daw, through a plugin -vst or otherwise- can transform it into B format and then only rotations and translations can happen. It CAN do it in real time, but if you work like me with recorded sound... there is no need to ask isadora to do something that you can render as a file to free cpu for other stuff.
So I only work with files transcoded into B format.
3) Virtual microphones (or not)
Once you have the b format the new amazing sound possibilities in Isadora allow the Audio FIe player to play HOA files, only then you can use rotators like my favourite IEM Scene Rotator you could place virtually infinite virtual microphones in the chain and move the microphones towards or far away from the sources in ordeer to navigate into the sound in real time in 6 DoF (six degrees of freedom : translation on x, y, z axis and rotation on x y and z axis). But just rotating inven without placinv virtual microphones is already astonishing because scene rotation is very different from traditional panorami potentiomenters in daw and mixers. PanPot (Panoramic potentiometers so called in the audio world just lower the volume of one ear (like isadora Audio Output "pan" input property). In ambisonic workd this is meaningless because through a rotato you really feel that the source is moving WITHOUT lowering the volume of one of the ears. The source is "REALLY" moving into space. So, unless you want 6DOF (for VR applications for instance) you don't need virtual microphones creation and translation in space : rotation is enough. Ambisonic rotation is more subtle, but so much more realistic. I'll never be able to go back, personally
4) Rendering
Thaat is where lies another complexity but essential stage for playing the sound. Ambisonic files fo either throug a multispeaker setup or a headphone. in my experience a 2 speaker set is not enough to perceive at the same time the sublte source shifts. It works better starting from 4 speakers. But it can work very well in a headphone. In the case of 2 speakers or headphones you need a binauralizer that renders whatever order into 2 channels. This is called binauralization.
So please remember that isadora is ONLY compatible with VST 3 (so, forget the Sparta Ambisonic plugins for the moment because they are VST 2) Download IEM plugin suite and try this patch directly with b format. It works for me b-format-isadora-test.izz douible click the scene rotator and move the yaw from -90 to +90 you'll hear (better with a headphone first) the miracle of ambisonics screenshot-2026-08-26-at-02.37.56-resized.png
Please keep me posted