@m-db wrote:
So the active crossover digitizes the input signal?
If it’s an analogue input, yes, and so it has to be converted back to analogue from digital (where the Digital Signal Processing is taking place) on the output side of DSP before it enters the amplifiers. Unless of course the amps have digital inputs (like Lyngdorf/Tact) in which case the signal can remain digital all the way from a digital source to just prior to the output section of the amp, at which point it will have to be analogue going to the drivers.
Before being sceptical about a possible A/D to D/A conversion step in a DSP with analogue inputs only, however, consider this: what’s most important is the quality of the DSP unit itself, not whether it adds an additional A/D conversion step at the input side. People get too high strung about these conversion steps, especially when not taking into account that the whole of the passive crossover is removed from the "equation" and instead letting a quality DSP handle the crossover function prior to amplification, on signal level, and with the additional amps required for the respective driver sections.
I can understand the principle among those with an analogue source and wanting the signal to remain analogue all the way to the speakers, even if - personally - I’d consider digitization in a quality DSP the lesser evil for fully active configuration rather than staying with passive crossovers for an all-analogue approach. Having said that and to reiterate, I understand the anti-DSP sentiment from those with analogue sources, if nothing else to stay analogue on principle alone.
Oh, of course: there’s also line level analogue electronic crossovers for active configuration like the ones found in ATC speakers, and this way there’s no digitization when going active.