If you don't want to move your speakers then build around them. The room's front is prime real estate for absorption. Regarding the exact form and placement of absorption, experimentation is your friend. More is usually better but specifically what form that takes and where and how those forms are placed is up to your room's unique acoustic interaction.
It'll be easier if you just build some stuff that can go in a few places. I've got 9 31"w 4'h super chunks (halved 23" insulation) and 20 4" 8lb roxul panels. In my current room, it just so happened that fully treating my rear wall defeated the room's Z axial mode which serves to neutralize my X axial response. In other words, I took my rear panels down, put 'em on the side, angled, and now I'm good.
The only thing I'd do differently is not make super chunks but, instead, make rectangular soffits. Why? Because more is more!