You need one Jl Audio F 113 or two of the smaller F 112 which are magnificent subwoofers.
Your room is huge, and the Maggies 1.6 are really too small for this size room 3.6 would be better,
More power couldn't hurt either it depends on how loud you play and how far away from the speaker you are.
The JL audio subs are really fast and blend well with these types of speakers, one of my customers had this subwoofer with a pair of $45,000.00 Scaena loudspeakers and the woofer could blend with this speaker which is really fast as well.