There are numerous advantages of active speakers over passives. Whether these are significant or not in a given instance will depend on the specific design goal(s).
Active speakers allow a speaker designer to do the a number of things that are not possible (or highly impractical) in passive designs:
- Avoiding caps, coils and resistors in the signal path, all of which degrade performance by adding distortion (not necessarily to the extent that it’s audible of course) and reducing efficiency.
- Placing the acoustic centres of the drivers in locations optimised for acoustic interaction with the baffle and/or horn, without being shackled by the necessity of keeping the acoustic centres of the drivers on roughly the same Z-plane.
- Implementing complex crossover filters enabling any/all of the following:
- steeper crossover slopes (lowering distortion/stress on drivers)
- better rejection of out-of-band signal (also lowering distortion/stress on drivers)
- more precise use of crossover phase cancellation to control directivity (see e.g. Horbach-Keele)
- implementation of cardioid radiation patterns allowing for wider-bandwidth directivity control (see e.g. Kii Three)
- Extremely fine equalisation of driver responses, enabling the designer to select from a wider range of drivers/driver properties in the first place.
There are of course many active designs that would be only marginally better if implemented passively. In these cases, the only real improvements would be slightly more linear frequency response and less stress on the bass driver(s) (both of which can be implemented in DSP in the playback system anyway). In these cases, the differences are negligible.
However, for the reasons mentioned above, there are certainly many possibilities that active implementations offer speaker designers that enable them to produce speakers that have flatter frequency response, more precisely controlled directivity, lower distortion, and greater SPL capability than would otherwise have been possible.