I have a 2 speaker setup, a 15 inch woofer and a horn. If I add a high-pass capacitor in series with horn does this change the overall impedance??
Yes, the series capacitor changes the impedance of the circuit. At very low (bass) frequencies the impedance of the capacitor will be very high (kilohms or megohms), in effect cutting off the sound to the speaker. The overall impedance will be the nominal impedance of your woofer, as if there were no tweeter connected at all. (eg 8 ohms) At high frequencies the impedance of the cap will be negligible and it will be equivalent to not having any cap at all, In this case the total impedance will be the nominal impedance of the woofer in parallel with the nominal impedance of the tweeter.(eg 8 ohms // 8 ohms = 4 ohms). This change of impedance is what causes the bass frequencies from damaging your tweeter. In practice however the rated impedance of a speaker is measured at it’s resonant frequency and it rises sharply as the frequency increases. A speaker that measures 8 ohms at it’s resonant frequency of 75 HZ can measure as high as 35 – 40 ohms at higher frequencies. (I have greatly simpl
