Active Sub and Head Unit Settings?

Hi,

I (think) I get the broad concept of integrating an active sub but the actual settings on both the amp and sub leave me a little foxed and I'd be grateful for advice.

• I have a pair of JL Audio front speakers in the doors (range 58Hz to 22Khz.
• A Pioneer DEH-80PRS head unit (set to Standard output (STD).
• I'm adding an Inphase USW10 active sub. (range 50 to 100 Hz)

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1. I'm wiring the sub using RCA 2 channel.
2. Enabling sub on the head unit and setting the high pass filter to 100Hz (and therefore sending everying below 100hz to the sub).
3. Setting the sub range control to 100hz (not really sure why a range control exists?)
4. Adjusting the sub gain (on the sub itself*) to balance the output with the front speakers.(*The sub also has a remote level control too - what's that for? Fine tuning from the driver's seat)
5. If I decide I want the fronts handling a wider range I'll adjust the high pass on the head unit. (Do I also need to adjust the sub's range control too?)

Is that broadly it or is it not that straightforward?

Thanks

Here's close up of the subs ins/outs and controls