The Altec 811 and 511 radial horns are nice too. They have collapsing directivity, which provides some acoustic EQ. You don't use as much top octave compensation with an Altec multicell as you do with the CH-3. The down side is there is nothing in the top octave off-axis from an Altec horn, whereas the CH-3 response is almost the same 30o to either side as it is on-axis. To me, that's important.