A beginner’s question about sources and microphone positions

[rAC]

i know there is a lot I don’t understand about MIR and its relationship to VSL instruments but can@Dietz or anyone else explain how a output of say a instrument that has output of say both the high surrounds and Decca tree should be positioned in MIR and where the MIR microphones (limited to two?) should go?

[Dietz]

Errrr .... you mean Synchron Instruments? If that's the case, please keep in mind that MIR is intended to be applied to dry signal sources. Room microphones aren't a meaningful source for it.

Or did I misunderstand the question?

[rAC]

That’s clear enough to me@Dietz Thanks.

[Dietz]

You're welcome! Glad I could help.

@rAC said:
MIR microphones (limited to two?)

Could be that you're mistaking Main Microphone and Secondary Microphone as "only two mics". 😊

Both of them can be chosen from up to four actual recording positions in the respective Venue. Due to the fact that we're talking about Ambisonics recordings, each of them can offer up to 32 virtual capsules, or virtual speakers if decoded spherically from Higher Order Ambisonics (HOA).

This is a typical example for a surround mic array in "legacy" 1st Order Ambisonics:

.... while this one relies on the more complex (and most of the time better-sounding) coefficient-based, spherical approach, showing the Azimut and the Elevation for each virtual source in a 3D space, downmixed to 5.0 surround:

Many of the Output Format Presets I created rely on a carefully chosen mixture of both approaches.