Bass Response on Dunlavy SC-IVa

I purchases a pair of DAL SC-IVa about a month ago and have been trying find the best placement in a less than optimal room. My room is 21ft x 12Ft with cathedral ceiling starting at 8ft in the back to 12 ft in the front where the speakers are set up against the short wall. I know they should be set up against the long wall but the existing HT won't allow this. The speaker are 49" from the rear and 20" from the center of the cone to the side wall. I have carpeting on the floor and ther is a 5ft openning 11 ft from the front wall.

I have experiemented with many placements but just can't seem to get the bass to sound right.

Any suggestions ?

Thanks