Salaam brother. The P99 manual when installing shows you two options for both passive and active setups.....In the active configuration the high out put is used for the tweeters.....Since I am using passive I will tell you what I did after talking to another person who was using it this way in a passive setup.....
P99= High range output
Mid range Output
Low range output
sub range output
According to the manual the high range is not used in a passive setup.
Mid range I connected to the front stage comprising components.
Low range to the rear coaxials.
And of course sub output to the sub.
Now I fiddled with the Low Lpfs and it is confirmed the rear stage tweets in the coaxials did start firing but the sound from the front stage changed also which should not have happened as the front stage is connected to the mid range output and not to the low range output which the coaxials are connected to.
Unless the p99 in a passive setup reads the front and back stage as one general speaker enclosure and the filters of the lows (lpf and hpf) and the filters of the mid (lpf and hpf) is affected by tweaking to the one or the other.