I'm using 1- 12" JBL-D123 on a 3/4" plywood OB board 24" high by 36" wide with a JBL 077 tweeter from 7 KC up. It sounds GREAT!!,but the low end is weak. If I would put another D123 on the same board mounted next to the first one( horizontaly), How much would the low end improve? Would the OB airy open sound suffer, from the side by side usage of the D123's? Thanks in advance for any advise,that some of you OB experts may give.-RUDY