I am planning to build some speakers for dj/sound reinforcement use. They will all use eminence drivers. The setup will consist of two <a href="http://www.partsexpress.com/pe/pshowdetl.cfm?&PartNumber=290-460&DID=7"> 15" Kappas</a> in a ported 5 cu. ft. box and four satellites on stands (two for monitor use), more than likely containing one <a href="http://www.partsexpress.com/pe/pshowdetl.cfm?&PartNumber=290-403&DID=7"> 10"</a> or one <a href="http://www.partsexpress.com/pe/pshowdetl.cfm?&PartNumber=290-401&DID=7"> 8"</a> woofer and a <a href="http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Product_ID=7607&CATID=49"> horn tweeter</a>. I am still deciding on the size of these satellites and whether they will be closed or vented. This will be an active setup. My quesion is, how do I decide what type of <a href="http://www.eminence.com/Pages/EminHF/HornsF.html"> horn lense</a> to pair with my tweeter? I guess one deciding factor is where I am going to cross them over but I don't know the difference between the types. Could someone please explain the difference between constant directivity, bi-radial and radial horn lenses? What would be more suitable for my application? Thanks.