Home made absorption panels.....

I did the exact thing Tvad suggested and covered the panels with a natural white needled cotton fabric at Wallmart, works good and looks good also.

My solution was similar to Tvad's but I used a heavy cotton cloth which my grandson and I painted. It was a nice project for him. We spent an entire day buying the material, building and then painting the panels. They have his signature.

A cheap method to help with boomy base is to take a few of those corrugated cardboard boxes from your local grocery store (in particular the ones with those 1-2" holes along the sides) and stuff them with pink insulation material. You can then put one upside down box into the other, effectively making a cube, or leave them open on top. Wrapping them in a soft cloth will also help with aesthetics. Unless you find the "Chicita" logo appealing.

These will work well, placing 2 behind the speakers in each corner and two behind the listening position in each of the rear corners if needed.

Heck, I have an IKEA couch wich has these huge, plushy pillows covered in some type of denim that has also worked well (well, well enough) when I was trying to convince my wife and daughter that audio can be fun .........

I suppose, that you could also cut up an old comforter and fasten the pieces to 1/4" 3x3 ft. pieces of plywood. I may try that.

Something else that comes to mind, would be a large plant at both ref. points. Of course, that would diffuse the sound rather than absorb it. I don`t suppose the diffusion would be as good as absorption. Just guessing.