Car stereo settings for subwoofer

It's been too many years for me to remember how little I actually knew about car stereo adjustments. I have a set of adjustments I can make from the receiver, and I have separate amps for my receiver and my subwoofer.

What is subwoofer slope? (On my receiver, the settings are "Low Pass Filter (LPF) Slope: 1, 2, or 3"; no dB settings, so I don't know what's higher or lower.)

There is a separate adjustment called LPF Frequency, for the sub cut-off frequency (50, 60, 80, 100, 120Hz), which I keep at 80.

There is a setting for SW Pos (subwoofer position): Near, Normal, and Far, which I have set for Far, as the sub is in the trunk.

There is a setting for SW Phase, for Normal and Reverse. I'm leaving that at Normal, because I cannot hear or feel any difference.

And of course the SW Level for gain. I have my sub amp already set at optimums on the amp itself for volume and gain.

Slope means the higher the number, the steeper (quicker) the frequencies are cut. I am guessing 3 is higher than one so a higher slope. Of course we are
guessing on what one to three means without a actual number.

Z

So a lower "number" would mean a lower frequency cutoff, providing more low end?

Yes the less steep the curve the more below the line (if it were a graph) so more lower frequencies. Use your ear and try each. Now we assume 1,2,3
do what we think they do.

Z

And the near, normal and far will plus or minus a millisecond echo delay to ensure your bass is in sync with the song by the time it reaches your ear.