Speakers are where the rubber meets the road, so focus there, rather than electronics for improvements.
The xls encores were very well executed speakers. To beat them on a budget will demand equal attention to the design, which unfortunately tends to correspond to cost. That might force you into diy at your budget, which you haven't specified. Is that an option? It's hard to recommend commercial products that may be a lateral move or worse, a step backwards.
I have a pair of xls encores, so I know where you're coming from. If you like those, you would probably also like other speakers designed by Danny Richie at GR Research (he did the xls/xls encore design), or any of a number of speakers that Dennis Murphy had a part in the design (Salk and Philharmonic fame).