Format X - O requires 4 Cardioid + 1 Omni.
Purpose: The X-O format recreate a balanced 360° surround environment, due to sum and differences with L,R and Ls, Rs the acoustic balance is very functional for 5.1 projects as well.
Advantages: stereo encoding (DAT etc.) very accurate positioning.
X-Mat: Ch1 and 2 L/R on B1 and 2 on phase, Ch 3-4 Sl and SR with Sl out of phase on B1 and 2. Ch3-4 level must be >1/4 comparing ch 1-2 and 5. On Ch 5 the omni assigned both to B1 and 2.
-L/R cardiod on X/Y coincident from 90° to 110° degrees
-SL/SR cardiod on X/Y coincident from 90° to 110° degrees 180° shifted from L/R
-Omni in the middle of the 4 capsules at same distance.