***        Anechoic recordings done by Dario D'Orazio           ***
*** reprocessed by Angelo Farina in SPS-12 and Ambix-16 formats ***

This folder contains the multichannel anechoic recordings of individual instruments and singers done dy Dario D'Orazio using an array of 12 microphones surrounding the sound source.
There are three opera pieces:
- G.Donizetti: “Come Paride vezzoso” from Elisir d'amore (Baritone, Choir and orchestra)
- G.Verdi:  “Di tale amor, che dirsi” from Il Trovatore (Soprano and orchestra)
- G.Puccini: “Oh Mio Babbino Caro” from Gianni Schicchi (Soprano and orchestra)

More info on the recording method and separate single-microphone dual-mono soundtracks are available here: https://zenodo.org/record/3628247#.YsG7NWBBzaw

In this folder I reprocessed the raw recordings, creating for each sound source a single 12-channel WAV file.
This is what is usually called an SPS recording (Spatial PCM Sampling), or P-format
I also encoded each sound source in a 3rd-order Ambisonics format (16-channels).
This has been done following the Ambix convention (ACN channel ordering, SN3D gains)
The 16-channels Ambisonics WAV files are also called B-format.
All the recordings for each of the three pieces are time-aligned. 
Most of them are exactly the same length, except a few ones which have unfortunately been cut a bit short.

These anechoic recordings are useful for creating MIMO auralization of a measured or computed acoustical space.
This requires performing the matrix convolution between the 12 or 16 channels of each sound source and the MIMO matrix impulse response representing the spatial transfer function between the source and receiver positions.
These MIMO impulse responses are usually formatted in two ways:
- 16x16 matrix (Ambix 3rd order to Ambix 3rd order)
- 12x32 matrix (SPS-12 to SPS-32)
The big advantage of using the Ambix format is that it allows you to rotate the source and the receiver.
The big advantage of using the SPS format is that it maximally preserves the spatial information.
The anechoic recordings can also be used for creating a "virtual orchestra", playing simultaneously all the individual sources employing a real or virtual multi-loudspeaker system placed on stage.

(C) Dario D'Orazio and Angelo Farina, 2022