solderdude
Grand Contributor
Still 8 ohm when a filter is used in both drivers.
When just filtering the tweeter at 14kHz the impedance will still be around 8ohm as the impedance of the FR will rise at higher frequency and the tweeter will have some extra resistance (because of the filter impedance at audio frequencies).
When just filtering the tweeter at say 4kHz and not filtering the FR driver the impedance will become a bit below 8 ohm (but not 4 ohm) for higher frequencies but this is not a problem as there is not much 'energy' above 4kHz relatively to the mids.
When just filtering the tweeter at 14kHz the impedance will still be around 8ohm as the impedance of the FR will rise at higher frequency and the tweeter will have some extra resistance (because of the filter impedance at audio frequencies).
When just filtering the tweeter at say 4kHz and not filtering the FR driver the impedance will become a bit below 8 ohm (but not 4 ohm) for higher frequencies but this is not a problem as there is not much 'energy' above 4kHz relatively to the mids.