Shop for a better subwoofer. Bitin pa rin ang Wharfedale SW150 or SW250.
OK lang ang Wharfedale subs when paired with bookshelf mains in a small room. The sub is supposed to supply the frequencies that are too low for the mains to reach. The problem is that your 9.6 floorstanders are pretty huge and already deliver loads and loads of bass. In this case, the SW150 sub (from 35 Hz) and the SW250 sub (from 30 Hz), would be next to useless because the frequencies they supply are already covered by the 9.6 (from 28 Hz).
With a Diamond 9.6, you will probably need a good 12 incher to keep you happy. Velodyne is the most popular sub in this forum, followed closely by Klipsch.
If you can't get a good 12 inch sub, don't bother getting a sub at all. Sayang lang.
