I think this is true, and not just because of aesthetics. When I placed my sub in the middle of my stereo speakers (due to lack of space), soundstage differed from when there was nothing in between the stereo speakers. Feeling ko may reflections nga, hence the "heightened" soundstage at the middle.
But then again, changing the placement of the speakers (location, toe-in/out, angle) also changed the sounstage height.
I also experienced the "dwarfed" soundstage that someone was stating here in another setup. Dipende talaga sa overall setup ng system and room and acoustics
I don't know if this is true but sounds scientific and would like to try someday.
In one of our casual get together, an enthusiast ask a question what is the easiest and most practical way to determine the optimal placement of subwoofer in a room. A lot speaks about tenga-tenga yan, coherence of sound, play with polarity, crossover, slopes, etc. but what stands out to me is the comment of another guy.
He said to try this technique:
1. Place the sub in your listening seat and play 80hz test tone (assuming you cut 80hz crossover) together with your front speakers.
2. Get hold a free Db meter in your iphone or tablet and walk randomly besides your front speakers.
3. Take note of the readings.
4. The lowest position is where cancellation takes place. Avoid that spot.
5. The highest position is the best spot that gives seamless integration. That is the sub sweet spot.
6. Place your sub into that position and enjoy the music in your listening position.
7. To verify, the lows should be pronounced and detail BUT you should not localize the sub location.
Ewan ko kung me logic but its easy to try and experiment. Unfortunately, I don't have any sub to play with. Baka meron dyan who could try this out if it holds water.
Anyway, audio is full of fun and surprises. All wants audio nirvana kaso wala pang nakakadiscover ng tuwid na daan. For me, ill die being dumb but with a happy ear. hehehe