Retrofit Subwoofer on High Performance w/o Subwoofer

[BigSpell6466]

Or is the same pins for subwoofer and amp side?

[Kenn]

Just go ahead and try. 
Enable the SUB from Orbit. 
Then take two wires put them into pin holes while the connector is plugged in to amp and at the other end of the wires, connect a speaker, headphone whatever you have.  If you hear something, than your amp can output SUB. 
You can also use ohm meter to test. Put it into DC 2 volts measure and see if you get any voltage. 
The pins are 7  and 15. (first green connector on the right. ) 

If you don't have a center speaker on the dash, 
It's the second pin from right.

2021 v60 D4 momentum 
I have high performance audio without sub and no center speaker on dash. My amp has 5 fins

Do you mean I should use pin 2 and 10 for sub when you say second pin from right or do you mean that they are for the center speaker? Pin 7 and 15 are taken, driving 
Right rear and tweeter.  According to this link. See post 16.

Also, what impedance is correct for an aftermarket sub and my 5 fin amp? I have optical, power/rem and then one 16 pin connector.

Thanks in advance