Acoustic panels

whats dynamat?

Dynamat is an acoustic treatment that is used primarily in car audio. It is a flexible sheet that can to be cut to fit door panels, hoods, etc..

Dynamat is available (in several variations) from Parts Express http://www.parts-express.com/

You will have to cover the entire room. But i am not sure, how effective it will be??!! Because you cannot expect a good result from homemade panels. Better you should try ready made panels. Now-a-days different types of very good looking panels are available in the market. You can visit  http://www.acousticmanufacturer.com/Noise-Barrier-on-Temporary-Fence-for-Construction-Site.html  to have an idea of different type of panels. Thanks.

I had serious problems with piercing upper midrange glare in an untreated room with my Focal 936's. A doubt Dynamat is better than rubber backed carpet which was my first solution. It was inadequate. I resorted to 12"X12"X2" acoustic foam panels. 36 sq/ft spread across the wall behind my chair. That stuff got the job done well for about $50 on Amazon. 
Dynamat, if I'm thinking of the right stuff, is designed to keep large areas of sheet metal from resonating. I don't think it'll serve your needs well. You definitely want to kill those first reflection surfaces and I'd start with the biggest one right behind you. Diffusion is a useful tool as well, and if you have the tools and facilities to make some diffusers you may want to try that. They're useful for softening the sound rather than just sucking it out of the space. Diffusers are especially useful behind and between the speakers assuming the speakers themselves are well balanced.