I too am considering DIRAC but before taking the plunge I spent fair amount of time working on speaker placement and room treatments as ejr1953 recommends. According to my spl meter I am pretty much getting +-2db from 20-1000hz. Needless to say, the sound has improved dramatically. I may get the usb calibration mic and the 2 week trial of DIRAC or REW and measure my room to see if there are any other areas I can address.
