You heard my CH3 knockoffs get smoked on axis by Bmar's horn over at Cope's the time that I brought the Karlsons. They do have even coverage though, out to around 90 deg. You're welcome to try them. I also have Altec 511Bs and will soon have JBL 2382 knockoffs you could try, but the JBLs will need 1"-2" adapter. I like Wayne's DIY idea too. That throat/flange section is the hardest part to DIY IME.

John