Cost to treat a room?

What does it cost? Well, doesn't that depend on what your room needs? If you can't define what problem you are trying to cure you are getting ahead of yourself to assume your room will just sound better by using commercially available treaatments. If you are not careful you could just end up spending a lot of money for the wrong stuff and end up with a room that sounds worse than it does now. And, to make matters even more interesting a lot of potential or real problems can be resolved by domestic furnishings strategically placed and or speaker set up.

Think it out................

Yes it is true. BTW Room treatments do not really change frequency response of audio equipment so much as room treatments will reduce or remove the audible effects of reflections off the walls. That can make it sound better or not depending what the reflections add to the sound that you find objectionable or pleasurable..