My recommendation would be to read up on the subject whether online or your local library.
An Acoustics Handbook would likely be too rigorous and delve into theory with formula and equations focusing on a physical principle that defines 1/100 at a time of the whole concept of Room Acoustics.
Look for something like HIFi Systems for a balanced practical understanding of what treatment is and how it is applied in a listening environment.
Then start to ask informed questions working toward a solution that is applicable to your circumstance.
Maybe someone here could recommend a suitable Title ...