Average Response is 3 db lower

[ohr2phone]

Hello,
i´m a new user and i´m wondering about the thing that my average curve is the 3 lower than the originals ... can anybody explain why?
look at the attachment

Thanks in advance

 

[John Mulcahy]

The responses have little overlap so outside the overlap regions you are averaging each response with something extremely small. You should probably be adding the responses.