Need Advice on Subwoofer Selection

Let me say up front that I'm not a bass freak but I've come to the point, regrettably, where I'm considering the addition of a subwoofer to my system. I say regrettably because I've always felt that subwoofers were an ersatz way of achieving full range sound quality and that a properly designed 2 or 3 way speaker in the appropriate room should provide more than adequate bass. And indeed, that has been the case for me with both my ProAc 2.5s and ProAc D38s in various room set ups.

Now, however, I find myself relegated to using my ProAc D2 bookshelf speakers in a rather large and not so well damped room. And despite breaking these speakers in for many hours with the Granite Audio, Ayre and Purist Audio burn in CDs along with the addition of some Primacoustic isolation pads, Van Den Hul speaker cable and driving them with a 250 watt per channel Hegel integrated amp - alas, the overall sound is a bit bass shy.

Because I am very fond of the ProAc brand, my inclination is to simply go with ProAc's ER1 subwoofer. However, as much respect as I have for the brand, the Proac sub has not been updated for 9 years and I have to believe that there has been enough advancement in subwoofer technology that a subwoofer superior to Proac's might be available at a similar price point.

It does appear to me that "speakon" connectors capability is the way to go. I'm looking for something with a small footprint and would be loathe to go with a driver any larger than 10 inches. To end range of my budget is $2,500.

Any advice would be most appreciated.