WilsonCreek
Active Member
I have what is probably a stupid question regarding capacitors and inductors in tweeter crossover circuits, but an internet search is getting me nowhere, so I thought I’d ask. As I understand it the capacitor, in series with the tweeter, essentially inhibits the flow of increasingly lower frequencies through it, resulting in a 6 dB/octave first order high pass filter. This can be refined to a 12 dB/octave second order filter by the inclusion of an inductor in parallel with the tweeter, which provides a less resistive path than the tweeter's voice coil for the lower frequencies at and below the intended crossover point.
My question is: Why do first order crossovers seem to always use only a capacitor in series with the tweeter, and never only an inductor in parallel with it? Is it because the amp would see very low impedance at the lower frequencies, and/or because the inductor would essentially short circuit the woofer (I’m sure there is a better way to word that)? If so, why couldn’t a well-chosen resistor in the tweeter/inductor pathway compensate for this? I would be grateful if anyone has the time to help me understand.
My question is: Why do first order crossovers seem to always use only a capacitor in series with the tweeter, and never only an inductor in parallel with it? Is it because the amp would see very low impedance at the lower frequencies, and/or because the inductor would essentially short circuit the woofer (I’m sure there is a better way to word that)? If so, why couldn’t a well-chosen resistor in the tweeter/inductor pathway compensate for this? I would be grateful if anyone has the time to help me understand.