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I have a good idea what it means. As the speaker plays different freqs the impedance at that freq remains reletively the same as the rating of the speaker. As the impedence changes it can cause peaks or voids of certain freqs I would think ....

Can anyone elaborate on this? Maybe some graphs or something. Plus maybe some info of other speakers too, as a comparison.

I have 8w3's in my truck. How would that compare to say a 8w7, 8w0, etc for the impedence?

 
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you kinda have it backwards. the impedence of the speaker is not the same. impedence has 2 seperate components in it, one is resistance, the other component is either inductance or capacitance. in the case of the sub motor, the second component is inductance.

you know how if you put a multimeter on a sub to measure RESISTANCE you usually get about 3.6-3.8 ohms? well thats part of the IMPEDENCE, but not all of it.

i'll attach a picture for you. the length of the line is the IMPEDENCE of the sub. you use the pythagorean theorem to find that value. each line has about the same resistance, yet one has a ton more impedence than the other. why? because of the huge difference in inductance.

as to why these lines would get such a difference in inductance, thats do to the different frequencies the sub is playing. some subs respond better than others. i think a good curve would be one that stays closest to 4 ohms, thus getting maximum power without creating an uneven response. hope that helps some

 
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the pic would help...

 
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isnt it reactance, not inductance you are reffering to?

with impedance being the displayed vector?

 
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yes it's reactance. i kept it kinda simple there.

if it's on the positive side of the y axis, it's an inductive load. on the negative side it is capacitive in nature. i was trying to keep the terms used to a minimum

 
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youll have to excuse me, i dont know enough about basic EE to really know what the heck im talking about.

isnt that part of the "power triangle" or something of that title, then? with inductance, capacitance, and XXXX? should prolly help me with this, I have labs in this to do in like 3 weeks....

 
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i changed majors, i haven't had EE in almost a year myself. my understanding came and went in all those classes. i think all my books are sold too...

power is another matter. that involves comparing the load to the voltage attatched to it. that's part of the idea in maximum power transfer is getting the voltage's phase angle to match the angle of the load.

on a plot for the power triangle, the y axis would be labelled reactive power (basically power wasted in the reactive parts, either charging and discharging capacitors or storing mechanical energy in inductors) while the x axis is real power. the square root of the sum of these squares gives you the apparent power. just wait til you get to 3 phase power and such. hahaha

good luck with labs, this isn't that bad yet. hope this helps you for all the times you've helped me

 
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it should, thank god i never have to do 3 phase power. hell, barely have to do AC!