The Sub8 supports pass-thru with high-pass filtering which is great. A common installation connects the line source (my PC) to the Sub8's inputs and then the Sub8's outputs drive a pair of amplified mid/high frequency speakers. By using the Sub8's high pass filter and low frequency cut-off, one can ensure the subwoofer and the other speakers are each handling the frequencies they handle best.
What happens if I connect the Sub8 over bluetooth when I'm still wiring the other speakers to the Sub8's outputs? Does the Sub8 act the same way, sending the low frequency component of the audio received via Bluetooth to itself while sending the mid/high frequency components of that Bluetooth audio to the other, wired, speakers?
That (to me) would be much preferred to connecting all three speakers over bluetooth. Passing the bluetooth audio through the Sub8 ensures it can high pass filter that audio before passing it along to the other speakers. You don't get that if all the speakers connect directly to the source over bluetooth.