Notch filters in series xover

[PeteMcK]

Would using a series notch filter tuned above the crossover freq of a series xover cause problems? i.e. the filter would be bypassing the driver and passing those freqs on to the other driver element. So, where you would use a series notch in a parallel xover, you should use a parallel notch in a series xover…???

[AllenB]

Since not only do series crossovers pass on the driver electrical differences, but are limited in their abilities to correct specific driver needs due to the need to be symmetrical, it stands to reason very broadly speaking that a driver should be response compensated and then impedance compensated in a self contained manner before it sees a series crossover.

If I were to go that way I think I'd prefer to simulate in order to reduce the complexity of such a crossover.

By the way, I don't see the parallel and series crossovers as opposites. One has independence and the other does not.

[PeteMcK]

thanks for confirming my suspicions Allen, my reason for contemplating a series xover was the lower DCR of the smaller inductor (2nd order), but having to use a parallel notch would blow that one out of the water... oh well, back to parallel xover, have to wind a few more turns onto the inductor....

[rabbitz]

Everything you add in a series xo effects both drivers. Even a simple zobel on a woofer can cause problems with the tweeter roll off such as extending it's lower end towards it's Fs. See pics of FR when a zobel is added to the woofer and it's effect on the tweeter. A series notch is not as bad AFAIK but still can cause other issues.

Unless the drivers are extremely well behaved I tend to use AR series crossovers where any mild peaks in the woofer roll off can be handled via the large inductor and the cap size in the zobel.

With series xo's, driver selection is very important as very little correction can be achieved.