I've recently purchased a pair of monitor speakers in order to build myself a better critical listening environment.
I've tried setting them up near one wall in a small room off of my living room, whose dimensions are about 8'x7', and which is about 8' high. The left-side wall is missing, as it connects to the living room. There are no acoustic treatments yet, as I want to get the basic setup right before investing in some treatment.
I have found that from where I sit, which is about in the center of the room, very low frequencies (below about 130Hz) roll off very quickly. However, if I slide my chair to the back wall, I can hear the bass quite well, down to about 50Hz.
What might cause bass to attenuate so sharply in the middle of a room like this, and is there anything I can do about it short of rearranging my desk to be up against the back wall?