If that were the case you wouldn’t be able to hear below 20 Hz with headphones capable of such.
Not true.
Headphones are considered a different environment.
It goes without saying that I myself made the same questions when first knew about room size and low bass.
Here is the answer I got from a very kind loudspeaker maker...
The smaller the room, the less help they will give to the speakers, and therefore it becomes almost impossible for speakers to produce the very low frequencies, inside these small rooms. A 17Hz soundwave is a bit more than 20 meters long, and when you try to play that in a room that is 3 meters long, the output is just going to be extremely low. As a general rule of thump, you need a room with half the length of the soundwave you want to produce, to get a decent output, at this frequency. That does not mean that you won't get any 20hz output in a 3x3m room, it will just be very low, and you really won't get much out of the speakers' ability to produce sound in this frequency range. And in a small room, you gain almost nothing by getting the A700 over the A500, the extra 7hz of depth you get from the A700, will most likely not be heard in that room.
So it is all related to the room size and room acoustics, not the distance to the speakers, as you refer to with the near field setup.
Headphones are also completely different, as they are not limited by the room, and you can get deep bass here.
Your 5000 euro subwoofer offering 13-80 Hz can bring a lot extra in a 3x3 room, but it will be mostly from the 35-40Hz range and up. There will still be output, it will just fall off drastically, when you get below this range, in small rooms.