The terms "series" and "parallel" describe the basic topology of the circuit, and refer to the connection arrangement of the DRIVERS. Look at the diagram link from Sean above for the first-order "series", and note the difference in driver connection compared to a "parallel".
But regardless of whether it's "series" or "parallel", the main inductor is still in series with the woofer, and the main capacitor is still in series with the tweeter. If you don't understand how this can be, it's time to do some homework. I'll give you a hint to get you started: Always think about where the CURRENT flows at a given frequency, because that's what makes the driver move. It follows the path of least resistance, just like water.
Best Regards,
Karl Schuemann
AudioMachina
But regardless of whether it's "series" or "parallel", the main inductor is still in series with the woofer, and the main capacitor is still in series with the tweeter. If you don't understand how this can be, it's time to do some homework. I'll give you a hint to get you started: Always think about where the CURRENT flows at a given frequency, because that's what makes the driver move. It follows the path of least resistance, just like water.
Best Regards,
Karl Schuemann
AudioMachina