Crossover Curiousity

Two nice Jubals to possibly place into use. The crossovers are simple, and I want to evaluate and learn from them. However, I suppose my question could apply to any passive crossover.

If I isolate the mid-range components (easy to do on the Jubal board), how do I measure the impedance the 'source sees' at the speaker terminals -- for the mid-range path alone?

So, my test setup would include a frequency generator >> amp >> speaker terminals >> to crossover board (With everything disconnected, except the components in the mid-range path.) >> LE5-5 driver.

I don't know the 'window' the 5" driver is expected to operate within, but let's assume 300 cycles to 1300 cycles are crossover points.

I 'fire it up' and start at 300Hz, dial it up to 1300, and back down to 300, so I know the test setup is working well -- because I can hear it via the 5" driver.

NOW, to my question: If the signal generator is set at 1000 cycles per second, how do I determine the Impedance the source 'sees' -- At the speaker terminals?!

Obviously, the crossover is complex (ie non-resistive) so the Impedance would be different at another frequency, say 1100 Hz.

I have a signal generator, Fluke, scope, and a few other gadgets.

SO -- again -- Is there a 'poor boy' way I can measure the Impedance the source 'sees' at the speaker binding posts -- given the setup I've described?

Please don't respond, "Yes." or "No". or "Why?" ;)

Greg

Sure... Put a small, say 1 ohm, resistor in series and measure the AC voltave across the resistor at each frequency of interest. Then review the math for voltage dividers. This will get you started... and eventually
bring up more question. Have fun.

Quote:

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Originally Posted by grumpy

Sure... Put a small, say 1 ohm, resistor in series and measure the AC voltave across the resistor at each frequency of interest. Then review the math for voltage dividers. This will get you started... and eventually
bring up more question. Have fun.

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Makes sense to me! Yes, the questions are coming a lot faster than the answers -- that's for sure! But, I'm sorta enjoying playing with this stuff again. At least I get to pause a bit in my 50+ years of oilfield work, and do something different for a few hours!

You are always helpful, Dude! :D And it doesn't hurt that you obviously know your stuff. Your responses remind me of the saying, "If I had more knowledge on the subject in question, I would have written you a shorter answer." ;)

Greg