Retrofit Subwoofer on High Performance w/o Subwoofer

[hanczi69]

First, he have a V60 Momentum, with bare minimum of everything, orbit says he have a PERFORMANCE AUDIO(base) BUT he does have the Amplifier under the passenger seat. So he bought the SUB already and tried activating it, after connecing the 7 and 15 pin following every instruction

In the performance Audio base, the speakers are driven by the IHU and not by the AUD.  The AUD is there for the car's warning and signal sounds. 

Do we need matching SUB(I think his is from v90[not BW].

It really does not matter.  The difference between HK, B&W SUB is the resistance.  HK is 4 ohms and B&W is 8 ohms. 

 

He said that if he activates HK audio it actually sounds better but still no SUB.

That does not make sense at all. First of all,  the correct setting is from 01 - Performance audio to 02 - High Performance audio. Because he has the entry level AUD without center output.   Then he needs to rewire the speakers to be driven from the AUD and not from the IHU. 
It's a simple test. Put the config to OEM which should be 01.  Then, disconnect the green plugs from the AUD.  Turn on the radio, you should still hear the sound from speakers driven by the IHU. 
So, what you need is, 
Unpin the speaker outputs from the IHU and wire from the AUD to the unpinned wires for each output. (4)  
Here is the wiring diagram.  https://forums.spaycetech.com/attachment.php?aid=334 . 
What he has is on page 7A_002A_Audio1
What he wants is "7A_002B_External_Amplifier_Audio2_V526_V54x"  
And then change the config to 02-High Performance AUD and With SUB.

Whats really funny, and I am losing my mind here. Is that I would assume its how you are saying. But its not, he's got the speakers wired through the AMP and what he just did is to add wires to pin 7 and 15. With the test which you advised, if he unplugs the green plug all speakers stops working except the one in the dashboard. (So it works like High Premium without the SUB, but orbit reads it as just premium) 

Its 6 speakers configuration.

I am attaching the picture of all connectors to the AMP. 

To add more spice, when he changes from Premium to High Premium he gets better audio quality but needs to move couple pins on connectors to get the front door speakers working. 
But the SUB is dead anyways.