What could be instead of side walls?

Cdc's, Rive's & Zaike's points are well taken. I faced a similar situation at a friend's house, trying to place Avanti 3's. Our fortunate difference was the floor, where the wood lay directly on concrete. I.e. we had no real suspension, but instability, as the floor wasn't level -- let alone the side walls that are outward looking to the listening position.
To make a very long story short, we came up with a compromise:
1) Speaker support: factory supplied bronze (I think) spikes for speakers on THIN granite, granite on 4 Nordost Pulsar points, Pulsars directly on wooden floor (it was hell getting these level!). BTW, Jadem has been experimenting with equip support for years now, and knows his stuff. Can you alert him?
2) Placement: far apart (!) and toe-in at around 75 degrees. Alternatively, we tried them parallel and closer (@6 ft) -- but that meant going back further for an image, into the corridor (no cigar).
This ain't perfect, but it's reasonably acceptable in a grand orchestra with voices (Mahler 8 -- around 900 people orchestrating).
Don't know if this helps.
Question: can we all come up with an idea for placing Mara's speakers in free space? Then, some of us can suggest the right speaker support. Cheers!

i have a sin to place a tv between the speakers but that's where i have my whole point viewing ld-music video collection that i have. also viewing vcd and dvd music videos as well. so tv should stay between.
the equipment stand is also standing next to tv between the speakers. so the only thing i can arrange right now is to remove the equipment stand from the inner space and run longer ics to amps thus "clearing" the objects standing between the speakers.
did anyone try to get a granite slabs from the monument shop?:^)

Before I finished my Basement( which included a dedicated audio room) I was using the Argent Room Lens.
Placing one on each side of the speaker and one in the middle.
It created sort of a boundry that allowed me to tolerate the sound.

I place my speakers along the long axis of the room by preference. My speakers are very far from the side walls and have terrific focus and imaging.

In some of the better articles on speaker placement they suggest that you should separate your speakers as far apart as possible to get the largest soundstage, HOWEVER, when the image begins to break up you have gone too far. Since you can't get further away from your speakers (i.e. a distance equal to the speaker separation), this might suggest that the speakers should be moved closer together.

sorry for misleading.
recently i've updated my measurements and it figures that the listening distance is between 9 and 10 feet depending on how i want to sit in my couch.
the distance between the speakers is also 9...10 feet.
all i did so far, i moved them closer so the speaker drivers is closer than tv and not on the same level with tv and the audio stand and move them a-bit closer so the listening distance is now between 8...9 feet with the same distance between the speakers.
the stage is stabilizing but on several recordings is still chaotic.