Interesting (or not) dilemma

I could use some advice here.
I have owned and enjoyed a pair of Revel M20's for a decade. Still like them 
with one important exception.
Due to logistics, I have them on stands some three feet from the back wall
with my seating position seven feet from the speakers --as far back as possible--there's a wall behind the chair.

The room is far from optimum-no carpeting and bare (ok some paintings) walls very solid parquet floors.
(I have a wife enraptured by minimalist design! Room treatments are out.

The problem. These speakers have a serious (on some recordings) bass "hump" at around 100HZ (my guess based upon a comment in Stereophile's original review--it IS there.). It is a distinct boominess
at a very specific HZ level and not present above and below it. These are rear ported speakers with otherwise wonderful sound.

As a solution I was thinking of adding a small subwoofer (REL7) and utilizing a cross over point to
take some of the bass load away from the Revels. Am I nuts? I could use some intelligent advice.

Thanks