1) Press the [PLAY DUAL] button to enter 'Dual' mode. The letters 'DU' in the upper left corner of the display indicate that Dual Mode has been selected.
2) Select one Voice from Bank 'A' and one Voice from Bank 'B' from the green buttons located to the right of the display screen.
NOTE: The upper line of the display indicates the number and name of any voice selected from the 'A' row of memory selectors. Likewise, the lower display line shows the number and name of any voice selected from the 'B' row.
3) Move the 'BALANCE' slider to adjust the balance between the selected voices.
Reference: Owner's Manual, p.6