@kijanki
I think the bottom line is that if a driver is crossed over close to 4kHz, it’s covering most of a human’s vocal capability that falls within the most sensitive range of our hearing ability. It keeps the crossover away from the meat of the music. Even if harmonics do extend as far as 17kHz, many folks have trouble hearing freqs beyond 8kHz.
I think the bottom line is that if a driver is crossed over close to 4kHz, it’s covering most of a human’s vocal capability that falls within the most sensitive range of our hearing ability. It keeps the crossover away from the meat of the music. Even if harmonics do extend as far as 17kHz, many folks have trouble hearing freqs beyond 8kHz.