4Ch. or 6Ch. Adapter For Replacing the 6 Drivers?

I've just replaced all 6 drivers in my 2020 Prime XLE.

Replaced the dash. Replaced the front doors to 6.5" /1" separate component. Replaced the rear doors to 6.5"/1" seaprate component.

The sound is much better. However, power is lacking to drive the aftermarket drivers, lacks bass and the non-JBL system is setup Front centric- meaning 70% of sound is coming from the dash and front door speakers.

The fader adjustment doesn't really help. This is what "Clean sweep" means. To erase the factory head unit setting to the speakers to par so the sound is set to balanced full range on all the drivers. I'm assuming Toyota did this to enhance the Bluetooth speakerphone and voice command system for the driver. So, installing a module such as Audio Control line out adapter, LC2i, 6i or 7i prior to the aftermarket amp will eliminate the factory head setting for the speakers. With a 6CH. set up, each speaker input would be maintained to control the balance and fader to one's liking.

Also, I noticed the front door speaker input is from the dash speakers connectors. When the dash speakers are not connected, the front door speakers do not work.

So, my question is... do I need a 6 ch. adapter connected to each driver in order to sweep the dash speakers separate from the door speakers. or Can I just go with a 4 channel adapter. Use the 2 front output from the adapter connected to the dash speaker to feed both dash and the door speaker. I'm asking if someone has the answer. Is the connection feed from the dash speaker a passive connection (where the door speakers have their own setting from the head unit, requiring a 6ch. adapter) or an active connection (where the door speakers are acting as one with a dash speakers, requiring only 4 channel adapter).

I started out wanting to just add a under the seat powered subwoofer for better bass response. Now I must do this to fully enjoy my new system in my daily driver. The sound coming from the front is just too much to the point it's annoying. The fader doesn't really help but to reduce the overall volume. I hope this helps a little.