I've been playing around with simulation on VituixCAD of converting tweeter's crossover from second- to third-order topology. It's simply an addition of a second capacitor to the existing second-order filter. Then, I tweaked the capacitance along with monitoring phase response until the tweeter's phase met the normal phase curve. As a result, I got the frequency response of the third-order case close to the original second-order, the second capacitor was 59uF.
I'm wondering what difference will we hear between these two types of crossovers when the FR and phase curves are nearly identical?
I'm wondering what difference will we hear between these two types of crossovers when the FR and phase curves are nearly identical?
Possibly nothing, they should sound more or less the same.
Whats the point of adding the extra cap? It is so large that you are not changing the slope of the tweeter rolloff. It is effectively just a wire at the freqs that pass through the original crossover. And thus is exactly the same as the original circuit.
There isnt anything magical about 2nd vs 3rd order just based on parts count. Those parts need to do something within the filter.
There isnt anything magical about 2nd vs 3rd order just based on parts count. Those parts need to do something within the filter.
If I'm correct here, you're only looking at on-axis response, which is only one part of the picture. The off-axis response can change more depending on the slopes and the directivity of the drivers at play, which is something you will hear in most rooms.
100% agree with this. To say it in slightly different terms....
You have changed the electrical slopes from 2nd order to 3rd order.
But you have not changed the acoustic slopes. (Or at least not very much)