Keta- Most subs are *not* like that.

Most subs just have a switch for 0 or 180 deg.

Some subs have a variable phase knob.

My sub has a variable phase knob that covers about 210 deg, but it also has an inverted input too. So for me... Between the inverted input and the std polarity input, and with the phase knob, I can get 0 to 360 deg. I wasn't aware of many subs with a knob that would do 360 deg alone...