Wayne Parham Messages: 18783 Registered: January 2001
Illuminati (33rd Degree)
It's mostly about matching directivity and shaping the forward lobe. In my experience, it all seems to come together somewhere around ~1.2kHz. But I've had 'em work a little lower, around 800Hz to 1.0kHz and sometimes a little higher, like 1.4kHz to 1.6kHz. There are a handful of things to juggle, but getting them all to work best always seems to happen in this crossover range for 12" and 15" midwoofers used with 90° CD horns.