You don't say what different ranges you've tried to work the crossover in. My response is that no mid range will give you adequate service at 3500. That's tweeter territory. If you want your mids to go up to 2500, they can't be any bigger than 3 inchers. And if you want to use neo's then you will have to limit your mids to no bigger than 3.5 inches or you will have integration problems that are caused by whole sections of the spectrum which are not there. In this case, the space between about 1600 and 3500. The fosters are mini woofers not midranges, and certainly not full range speakers.

Marlboro