What are your thoughts about "how much is left" from the original driver's specs like response graph, efficiency etc?
I've seen how midrange drivers that are predicted to have different efficiency in HR are much closer or even the "lesser" driver had better efficiency in real life, when talking with people about results they've had with horn loading.
For a subwoofer, the inital efficiency seems to have nothing to do with the outcome after the loading.. For a midbass, how should I look at that? How should I look at xmax requirements for midbass?
Is there any importance to look at a driver's efficiency at 100Hz if I aim for a 100Hz horn?

Many thanks for your time
Adam