Welcome Mansardian,

thanks for your interest in MIR and MIRx.

The question you pose is a good one!  :-)  I'll try to answer it as thoroughly as possible, as it may be interesting for others, too.

It's important to understand that the concept behind MIR is based on Ambisonics completely. Among many other benefits^*) this gives us the possibility to put the original (dry) signal on exactly the same spot in the virtual room where the signal source stood during the actual IR-recording process.

This portion of the sound can now be regarded as "virtual spot microphone", which will blend perfectly time-aligned with the wet signal derived from the Main and Secondary Microphones in MIR Pro (or the combined blend of them in case of MIRx). Working with main microphone arrays and mixed-in spot mics is a very common approach for all kind of orchestral recordings, but the amount of the close spot-mics is a variable, not a fixed value (... depending on several technical factors like the Venue, position, distance from the main mic, but also on artistic ones like the composition, the arrangement, and of course personal taste, needs and preferences).

To cater this vast and quite different demands wouldn't be possible with the direct signals that come "burnt-in" with the raw impulse responses used for MIR. You wouldn't be able to change the amount of the "spot mic" mentioned above (read: the panned and pre-processed dry signal). And even worse: Due to the fact that MIR relies on Multiple IRs, the mixture of the direct signals coming from eight IRs will result in a bloody mess of phase cancellation and transient smear. ;-P

Therefore, all remnants of direct signals were removed carefully from the impulse responses used for MIR. In other words: "Full wet" is not what you would hear in the chosen Venue! Like that you will miss all the highly important location cues of that reach you ear before any reflection coming from the room will do.

*) ... more technical details are covered in a little add-on to MIR Pro's manual called "Think MIR!". It is available for download from the "MyVSL" user area.

... please let me know if there's more information needed. :-)

Kind regards,

:-) *winkt vom Rosenhuegel hinueber zum Wienerberg*

Originally Posted by: Oguz Sehiralti

[...] In other words, if I'd like a mix of main mics with NO spot mics, how would I achieve this with MIR Pro 

You will always have to use a certain amount of dry signal (even if it's just very low in volume, by comparison), as the recorded (original) direct signal component has been removed from all IRs used in MIR, for reasons outlined above. It was meant to be replaced by the readily Ambisoncs-positioned input signal.

BTW: You can assign dedictated outputs to MIR Pro's Secondary Mic by means of the Matrix view in the Output Format Editor window. _This_ signal will be wet-only, though. Two different Ambisoncis-decodings would mess things up completely. :-)

HTH,