The attachment is a block diagram of the Ventriloquist center speaker, with front sats connected. Dr. Hsu reviewed and says it is accurate. A key element is the fact that the 4" x 6" drivers have dual coils, one 4 ohms and one 8 ohms.
Retread - you could add the "switch" to show the effect of bypassing the 4x6 speakers when removing the "Ventiloquist efffect". Nice diagram! I didn't realize that there was dual coils used. Interesting...and the next question - does the switch take-out or leave-in the high pass filter to the L/R speakers?