Eh hem!...Subwoofers... What do ya know?

Are 2 subs better?

Honestly a lot of this is an economic problem. Not just expense of the sub, but the room. Can you afford / do you have the space to locate each sub ideally?

If so, then yes.

If not, a good compromise is room acoustics, 1 sub placed as well as you can plus an EQ.

In my own situation, I really really don't want to be moving a sub 6" 12 times to compare and measure. I have about 2 locations where this 100lb beast can go,  and I'm going to put it there and EQ it and call it done. :)

I guess I’d have to see what “placed ideally” equates to. Some light reading have the impression that one on each wall was the answer. How true that is I do not know.

if 2 $500 subs are better overall than 2 $200 subs then so be it. I’m just genuinely curious  as the “4 is better than 1” motto never mentions “good ones“ versus “ones that should work ok”.

2 subs are better in that you have more power, and more driver pushing air.

So absolute terms, sure, you can increase output by 3 dB with lower distortion.
But if you place the subs symmetrically, I would imagine that you end up reinforcing the same mode and anti-modes. Maybe some one has a better idea?

As far as I know, you place the first sub as well as you can, and then place the second sub so that it fills in any nulls.

Is this not how the cool kids do it today?

A very interesting, and appealing discussion. I've never heard a subwoofer swarm demo--perhaps a demo in Florida in February (he said, hopefully)? Two questions please:
1) From what I read here, it seems like multiple  in-wall subwoofers would be a good swarm solution...yes/no?
2) Millercarbon: what subwoofers do you use for 16ohms?

Best wishes from Atlanta, where Christmas buyers are also swarming...

@erik_squires  placement in terms of nulls makes perfect sense.  I will read more into that