It sounds as if you expect to input a signal into CARA and that isn't how it's used. Instead, a room is modeled in the CARA CAD portion of the application, including walls, speaker and listening positions, plus special reflective surfaces like carpets, wall hanging, etc.
Once completed that model is run through a processor called CARA Calc. This engine does all the computations for both numerical and graphical output.
Certain of CARA Calcs outputs can be viewed as 2D or 3D charts. Some of the latter can also be viewed as video based on, for example, time. For this they use a third piece of software, so CARA is really three applications that all work together fairly seamlessly.
If a model of your speaker(s) is not included in the library that comes with the product take a look on Elac's site. They have a listing of models created by endusers that have been "tweaked" by Elac's staff. If the speaker needed is not available anywhere it is not that hard to model it using CARA's loudspeaker editor.
FWIW, I am fairly computer literate and have used a variety of applications in my years. Until CARA I had never used a CAD package of any sort and it wasn't difficult to figure out. The help files are very complete and should be referenced at all steps as they point out most of the pitfalls.
Hope that helps.
