In my opinion it strongly depends on what you are trying to accomplish and the problems that exist before beginning. My expience for best results is in addressing a very lively room with excessive echo/reverberation. This can be done with both application specific sound treatments, but frequently can be performed just effectively with some careful and tasteful decorating.
You comment specifically on a pronounced boom at a very specific frequency and report that their single solution only affected the "boom" by 0.5 db. What was the measuring of the "boom" to begin with? What other approaches did they pursue - speaker placement, listening position, toe in, etc. . . To me, it is not the end of the world having a slight excess at certain frequencies as achieving a perfectly dead flat room across the frequency range is near impossible/difficult and liveable at the same time.
You comment specifically on a pronounced boom at a very specific frequency and report that their single solution only affected the "boom" by 0.5 db. What was the measuring of the "boom" to begin with? What other approaches did they pursue - speaker placement, listening position, toe in, etc. . . To me, it is not the end of the world having a slight excess at certain frequencies as achieving a perfectly dead flat room across the frequency range is near impossible/difficult and liveable at the same time.