I did my own thing and use an old Klipsch K43 driver for the 15" bass and a PHL midrange with the Emminence horn up top. The horn I use for the Emminence driver is an old Altec 32b bent horn.

You can always choose to mix and match a bit. Use the JBL 15 inch down low with the MUCH cheaper but still respectable Emminence driver up top. Many people have used 40 by 90 degree horns from other companys like Peavy instead of JBL or Emminence.

That's the freedom of do it yourself. If your not sure if something will work post a question on the forum. There's lots of support here. Be forewarned though. When you start building you're not sure. Then you start having fun checking things out. Next thing, the closets fill up with audio parts ....

Grant.