Faital Pro 15PR400 is decent up to 4k...But with any 15 you will have the beaming problem as you go > 6-800Hz, how big a problem that is in your situation is up to you.
See measurements here: OBL-15
Also look at Humble Home HiFi Calpamos project using same 15, http://www.humblehomemadehifi.com/download/Humble Homemade Hifi_Calpamos.pdf
See measurements here: OBL-15
Also look at Humble Home HiFi Calpamos project using same 15, http://www.humblehomemadehifi.com/download/Humble Homemade Hifi_Calpamos.pdf
I have not much experience with Monacor but might consider one of their 12” PA drivers in my next project. That particular one you found seems to have a plastic treatment cone. Not sure of why hopefully it only flattens the cone breakup resonance frequency but it might “muddle” the midrange as well if you plan to use it as midrange you may want to look for high sensitive PA paper cones that you can play around with band stop filters without loosing all the sensitivity.