To get an objective description of what "poor acoustics" means, we usually suggest measuring the acoustic performance of the room, such as reverberation time, speech intelligibility and other factors. From this assessment we can, with the help of a room model, precisely predict what measures will be needed to achieve the optimum acoustic quality in the room.
The choice of surface materials is also important but many factors influence this decision. Many people focus only on selecting highly absorptive materials but where they are placed and the size of the covered area matter as well. For instance, it might be a better choice to cover an entire wall or ceiling with a material that only absorbs 50 percent of the sound, rather than covering only half of the surface with a highly absorptive material.