Room Treatment

I've used GIK and yes, I made room measurements using REW software first.  Before you buy anything, do yourself a favor and optimize speaker and listening position before you begin adding treatments.  Simply optimizing speaker and listening position, guided by measuring responses, can do more to improve frequency response than a whole room full of treatments.   Treatments actually help most with reducing low frequency decay times, which produces articulate vocals, and treating early first reflection points, which improves imaging.   The more you can do on your own, the more you will benefit from consultation.  GIK is a great resource, but they are in business to sell, not to help you make most efficient use of your investment in treatments.   All of the companies that sell treatments offer really good tutorials and tools on their websites.  Real traps, for instance, offers a wealth of information which I encourage you to use.  But I suggest you stick with GIK for products and advice. 

ama732mx1, It makes a difference that you are dealing with a living room  where you do not have complete freedom due to a concern for aesthetics. Typically one also has limited flexibility in speaker and listening position in a living room. 

I have miserable acoustics in my living room, where having traps and panels all over the place is a non starter.   I went with a different approach in my Living Room.  There I used a Synergistic Research Black Box and about twenty SR HFTs.  I was skeptical about both of these products, but I found them surprisingly effective in improving vocal articulation which was a real problem in that room.  It was so bad it was hard to have a conversation much less enjoy music.  Even my wife, who is a complete non-believer in such things, was really impressed by the difference.    However, I evaluated them upstairs in my dedicated living room, and the SR products did absolutely nothing there.  So, if you try the SR products, make sure you have a 30 day return option.  

Finally, I picked up a Lyngdorf 2170 for use in the living room, which offers some very effective DSP using Room Perfect.  It is a really nice piece.  Not what I would have expected from a class D amp at all. 

There is more than one way to approach this.  In a dedicated room, I'd go traditional room treatment.  In a living room, I'd start with DSP and go from there in order to avoid or minimize panels and traps.