Help! What’s the best placement for wall-mounting Era 300 surrounds?

I’m not sure your layout meets the needs for “ideal wall-mounting locations”.

A recent post mentioned ceiling mounts; that might be the solution here? 

I would recommend getting a console table to go behind the couch that faces the TV. Then you can place your surrounds on that instead of try to wall mount them.

The other option as ​@nik9669a has stated, would be mounting them upside down on the ceiling

Or floor stands, but the op asked for wall-mount options. 

Floor or table mounted are good options if you can get power to them, otherwise the ceiling mounts should be considered.

Thank you all for your thoughts. It sounds like the best way to go is mounting them to the ceiling. any thoughts on the placement?  please see attached photo of where I thought i’d place the Era 300s

Thanks again!

I'd be tempted to try the 300s there but also closer to the couch and the left one moved in to match the right. Also further past the FFL and equal distances.

Temporary stands, like a ladder, or a couple boards screwed together, whatever is easy and cheap.

I really dislike open concept layouts.  At least for Dolby Atmos.  My room is also a tough cookie to crack.  Fortunately I have a very nice wife who puts up with my great room nightmare.

I’d seriously consider the table behind the sofa similar to the picture below. Any ceiling mount is going to limit furniture placement to get the optimal surround effect. Just make sure the table is tall enough to allow the Era 300’s to clear the back of the sofa. Era 300 Stands would work also.

One more point…in a space such as yours the low-end only from the ArcUltra is going to be rather weak IMO. If a Sub4 is out of budget strongly consider the Sub Mini.

If I'm reading that floor plan correctly the floor is polished concrete, not friendly to adding power outlets or cord covers run on top of it.

Carefully done ceiling mounts can leave minimal visible damage if moving them is necessary, later changes are something to consider when doing the install.