AvsFan, tone controls have a limited range of adjustments and EQ is another old school solution (rather expensive and can be noisy). Can you add DSP (digital signal processing) software to your system? Easy if you're using a computer as a source, if not miniDSP has hardware solutions. Using DSP allows you to first measure the room/speaker setup to determine if where the fault lies (room, speakers, setup, or your tastes) and make adjustments and then re-measure. You can even add room treatments to see if that helps. REW (room eq wizard) is free software and powerful but not easy to master. Dirac isn't free or as powerful but easy to use and is what miniDSP uses. Both require use of a calibrated USB microphone for testing purposes.