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Anybody ever use a tweeter in series with an inductor to achieve the neccisary value for a zobel network? If anybody knows the theory behind why this doesn't work I would love to hear it. †hanks
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reduce the amount of RF noise picked up by the tweeters acting as antennas.A Zobel network's purpose is to compensate for the inductance of a driver. Adding inductance would seem to be a bad compromise if all you are trying to do is adapt an existing Zobel to a different driver. It would be better to change the Zobel to values correct for the driver in question, IMO.
You are certainly correct about adding inductance being a bad idea. I have no doubt about that. But what I'm curious about is if using a tweeter for its inductance value in series with another inductor to achieve the Caluculated R value for a zobel network, relative to a woofer. The two potential compromises I envision are obviously the Vc of the tweet changing impedance, which affects the value of the of the total inductance for the zobel network. The other compromise I foresee is the value of the Capacator will not coinside with the Value calulated for the Zobel network or an ideal 1st order filter for the tweet simutaniously.Another curiosity that I have is if the Zobel network is smoothing out the increase in Re of the woofer with respect to frequency, what happens to that as it would be diplaced through another speeker(tweeter in this case). That could contribute to prematurely damaging the tweeters Vc in some fashion maybe?
a Zobel network is intended to make the woofer look like a resistor at higher frequencies, so that the low-pass filter that feeds the woofer works properly (see link). If the woofer inductance is large, the woofer impedance will be higher at frequencies where the crossover is intended to reduce the woofer output. This will compete with the crossover impedance and allow too much power to get to the woofer. The result is too much sonic output from the woofer at frequencies where it sounds bad.The tweeter impedance is used in the design of the crossover, but does not enter in to the Zobel network design for the woofer. You do not need to compensate the tweeter impedance for the Zobel network. The R value is the power resistor used in the Zobel network, and should match the nominal woofer voice coil impedance. The C value in the Zobel is determined from the woofer inductance, as per the link.
The amplifier is assumed to be a voltage source, so the crossover takes care of keeping excessive bass energy out of the tweeter regardless of whether there is a Zobel network on the woofer, or not.
Thanks Al, thats the info I needed in order to understand that its not a good configuration. I might build it anyway just to see how it sounds, then I can hear why its a bad idea. Thank you very much for your knowledge.
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