Adding a Sub do i go with 1 or 2 ?

astewart8944 is right about more taking care of modes, but while the research shows greater benefit from more, it also shows greatly decreasing incremental benefit from more than four. So what you want is four. Also they need to be placed asymmetrically, and somewhat out of phase. Do this and you'll get amazing bass. Read the Swarm threads.

Hard to believe how far off you guys are. Its not a question of which sub. Only when you get to four subs, properly located, only then does it matter which drivers you are using. As long as you stick with the old paradigm of one or two, you are so far off base it really does not matter what you use.

Insert gif of head banging into keyboard until turned to mush. That is what you’re doing.

Frankly I was more than a little shocked to learn the answer has been there now for well over a decade. Seriously. Go do a search.

Guess its like autophagy, induction cooking, or any of a number of paradigm-changers. Hardly anyone adventurous enough to adopt the new. Almost everyone exposed to newer and better lamely sticks their head right back in the same old feed bag.

Seriously. Go read the threads.