How to do room acoustics correction the easy way.


I have been researching all the methods to do room acoustics correction with an existing system with a existing DAC.  What I want  is a device that connects between my stereo preamp and stereo amp that will do the work.  I want it great, but I want it simple.  I want all my sources to go through the “box”. 

Am i missing something obvious, or is that not how this stuff works?

Your feedback is greatly appreciated....
fastninja12
So more info.  Room is a converted garage 24x22x10.  No longer looks like a garage.  Sheet rock walls. Lots of wall treatments.  GE Refs sit 4’ out from the wall with 9’ between and 9’ to listening positions.  Directly behind the sofa I use, there is a large weight machine and treadmill.  I know I am having reflection problems, I hear it as smeared midrange...guitar and vocals.  I hung 4 heavy shipping blankets immediately behind sofa about 6’ high that extended about 8’  across. Smear and edgyness went away..  That’s what I hope to mitigate with room correction software.  I don’t want the blankets as a trap...
To continue, will my plan work or should I do more room treatment.  I have so many reflection points before  the wall opposite the speakers...