Seeking Consultant/Designer for Acoustic Treatment of Room

I built a dedicated audio room a little over a year ago that has a whole lot of plusses, but definitely needs some acoustical work to deal with some tonal artifacts.  I am looking for someone to help me diagnose the issues and then design treatment to address things.  Any 'Goners happy with a particular firm that worked on your rooms?  (I recall Rives Audio, but they no longer service home installations.)