I, like Zaikesman, am very surprised by your findings. However, every now and then some things serendipitously fall into place and what should be a huge problem is balanced out by something else that should also be a huge problem just by luck. That being said I would suggest that you do as Newbee suggested, but I would add a bit too it. Take the measurements at the listening position then pick 2 or 3 other positions that are various distances (say 1 to 3 feet) and various directions away from the primary listening positon. The purpose of this is to see if you are sitting in null points for the frequencies that should be accentuated. It's simple enough to calculate these and I would point you to our website tutorial
the listening room . We also have a test CD that may be useful, as it has test tones calibrated for the Radio Shack analog SPL meter.