Cross over ah ha moment..now im confused

[bmc0]

The main practical problem with the giant cap and tiny inductor is that most amps won't be very happy about driving a load that's almost a dead short. Check the system impedance.

 

[wwenze]

Yes. In a vacuum, each inductor and each capacitor are each one order filter and together can form a second order crossover with two combination that yield the same exact FR solution.

The difference comes when you try to put it into reality. Load impedance, source impedance, load impedance vs frequency, inductor resistance, $$$$$$$$ because inductors at high values and high amperage and expensive as heck.

And you can't get the exact value e.g 1362uF or 1/1362H which is why you have to design with standard values and that also limits what combination of values you use. Unless you use DSP then you can use exact values in the formula which is why DSP wins.

View attachment 479908

In this particular case, this second solution is the bad one because where are you going to find a 470uF bipolar capacitor that isn't going to be a large electrolytic and hence measure poorly.

 

[Ronw]

Thanks folks!