To add to Tom's and Brads suggestions. Before beginning any acoustical treatment, you need to know exactly what the problem is. Is it flutter echo-if so from where? Is it Reverb? If so, what freq is the worse and are there any freq close behind in level?
You HAVE to know those things BEFORE starting a treatment. Kinda like going for medical treatment. Hey Doc I heard this new pill is great. I want some. BUT FIRST the doc has to know (as least as best as he can) what YOUR symtoms are-not the spokesperson or actor on TV that you heard.
The better you are at finding the exact cause of the problems (there may be several), the better chance you have at fixing them.
Oh Tom BTW-we make a lot of money with dead cat panels
, because people don't want to spend the money up front to do it right, it is more about the "look" of the room than the functionality of it that really matters
. Sometimes just throwing up a bunch of them will do wonders, usually because the room was so bad to begin with.