Posted by Wayne Parham [ 70.234.105.145 ] on August 19, 2006 at 23:22:45:

In Reply to: Professional Four Pi Plans posted by Hakn on August 19, 2006 at 18:38:06:

I've sent plans to your Yahoo address. If that's not current, let me know your new address and I'll send them along.

The coil in the woofer circuit interacts with the woofer's voice coil to form a sort of shelved response with attenuation that kicks in at 1kHz. It doesn't really provide 6dB/octave attenuation because the load is inductive rather than resistive. That's why I call it a pseudo-first-order, since there is no Zobel to fix load impedance. But as you've inferred, the woofer's natural rolloff helps out in this regard.

If you move everything down to 800Hz, you may or may not be able to use this arrangement. The woofer won't be rolling off yet, in fact, it's still climbing on axis because of collapsing directivity. You might add a Zobel, see how that works. Or you might go with a higher crossover slope.

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