Polk Audio DB691 Speaker (Ceramic) That rear deck is aching for thunderous loudspeakers like the db 691 6x9-inch 3-way loudspeakers, featuring both a 25 mm liquid-cooled dome tweeter, a 19 mm super tweeter and plenty of polk technology that makes db series mobile audio loudspeakers a great choice. dimensions - oval cut-out height 5 13/16 (14. 76cm) inch dimensions - oval cut-out width 8 5/16 (21. 11cm) inch dimensions full-range mounting depth - bottom mount 3 3/4 (9. 53cm) inch dimensions full-range mounting depth - top mount 3 3/16 (8. 10cm) inch dimensions grille - height 1 1/4 (3. 17cm) inch driver complement mid/ woofer - diameter 6 (15. 24cm) inch driver complement mid/ woofer - oval height 6 (15. 24cm) inch driver complement mid/ woofer - oval width 9 (22. 86cm) inch driver complement mid/ woofer - quantity 1driver complement mid/ woofer - type dynamic balance driver with poly composite conedriver complement tweeter - diameter 1 (2. 54cm) inch driver complement tweeter - quantity 2driver complement tweeter - type silk/polymer comp