unless you have a reference mic and Rev (free room analysis software) then just placing an absorber on the wall isn't going to do what you think its going to do. there is no such thing as 95 % dampening unless its 24" thick foam or glass battens or an open window. all dampening materials have only a select frequency band that they absorb, so what you will end up having is a room dampen too greatly in one band of frequencies while another band wont have enough and what you end up having is a bad sounding room that no eq is going to fix.
One way to avoid this besides using forementioned reference mic and software is to build a book shelf like phase diffuser, which like the names says is a diffuser that splits the frequencies up and refracts them at different angles such that standing nodes are well dispersed.
but considering REV is free and these days reference mics are quite cheap - especially for room analysis, it would be a good way to go.
a book shelf works very well as a phase diffuser - plus it adds a bit of elegant snobbery, especially if the books look intelligent (you don't have to read them btw) but used books are cheaper than phase diffusers by a far amount.
Floyd Toole of NRC fame ( he is now with Harman) was the one that suggested this to me while building my studio many years ago, while at a AES meeting in Toronto.
Having phase diffusers will not alter the tone of the room but will reduce or eliminate nasty resonate room nodes. The only area they are not so good are low frequency (150 hz or below) where open windows and bass traps are your best friends. Again if you spent $5k on your hifi equipment, at least spend $500 (at the most) on a reference microphone and REV or similar software
