Format I requires: 1 omni, 1 shortgun, 1 figure 8.

Purpose: I format provides a strong fast front to back motion. It's 360 degrees proximity sensitive. It does not provide a very accurate L/R position, but it favorites the front to rear passage instead.

-Advantages: stereo encoding (DAT etc.)
Compatibility: Stereo, mono (with proximity) and good 5.1 ready to encode
Disadvantages: Poor stereo accuracy, proximity sensitive.
Main applications: It's best use is with loud impact sound where you can position the mics far away. Gunshots, explosions, flares, swash etc.

X-Mat: Ch1 the omni to B1 and 2 to L/R on phase. On Ch 2 the Gunshot on B3 and 4 to L/R B3 out of phase. On Ch 3 the figure 8 on B1 and 2.

Position: near coincident.The shortgun point at fugue point surround, the figure 8 at side positions (180 relative to shortgun).