inexpensive room treatment options

Depending on your workshop capabilities, I'd recommend my very own DIY imitations of RPG diffusors. Please email for my instructions for making them if you could consider this: you'd need a table saw or some other good way of cutting Styrofoam cleanly and neatly, and a work table, and THAT'S ALL! I have 23 square feet of RPG-style diffusors on my front wall, three of them added one at a time, and each one made a major improvement in the sound. My electrostatics have a strong back wave, maybe you don't have that, but the middle of the rear wall is an important surface to treat, and absorption isn't the best way to go.

I agree with both Sean and Tom in regard to using diffusers on the back wall and withdraw the canvas painting suggestion (unless that is all that you can do). The paintings do however work at the first reflection points on the side walls and offer superior sound (to bare walls) in my setup. When I went back in time (in my mind) I recalled that the addition of either painting on the front wall degraded the sound somewhat (even with a cloth cover). The reason that the painting is where it is right now is because it is the only place that we could find space to hang it. I hope that this is not taken to be sacrilegious, but I enjoy the painting as much as I do the Hi-fi setup.

I find paintings to be terrible at the reflection points. Canvas may be good at absorption, but oil paint on canvas is just as bad as a bare wall. Maybe you are into modern minimalist art and are staring at a blank unpainted canvas with just a signature in the corner? Said with my best euro bohemian coice "It is the artists interpretation of the difference between audio cables or maybe the effect of a PowerSnake Hydra on the background."

Damn, I screwed up my attempt at humor once again. That should be "voice".

Metaphysic's: The majority of our art is Haitian and the canvas grain though covered with acrylic paint (except on very old pieces which are oil) is still clearly visible. I disagree that this treatment is not superior to bare wall (dry wall in our case) as I have experimemeted with well over 50 paintings VS bare wall in this room, including having entire walls bared for repair and new paint. This may not be a typical room in that most of the wall space (75%) is covered by books and or art (even the doors).