Quote Originally Posted by donaldpatten View Post
Mike
We need the woofer to be a flat impedance from 400 Hz to 4000 Hz. Do have Fluke 87 DMM?
Add a Zobel to your woofer . This is a series R & C across the woofer . Pick the values that give a flat Z curve. Use an L Pad to find the proper R (10 ?).The C ( 30 uF ? ) can be several caps in parallel

Make a CD of the test signal on my web site. and have it repeat 10x or more

To get the delay time we need to play the test CD , with the woofer on, and look at the acoustic signal 12 inches on axis with a scope and almost any omni microphone. Connect the HF horn in series with a 4uFd cap.
This gives you a bare foot woofer and a single pole HF high pass crossover.

Sync the scope with the amplifier output and turn the HF on and off.
Note the LF peak and the HF peak. Estimate the time between the peaks (300 to 500 micro seconds )

Don
Very nice explanation Don ! Thanks for helping out Mike....