I don’t think you will get the full benefit of the Era 300s from those positions. And since you don’t want to use speaker stands, you have very limited options.

If I were you, I would consider using a pair of Era 100s instead and placing them at these locations in red:

I don’t think you will get the full benefit of the Era 300s from those positions. And since you don’t want to use speaker stands, you have very limited options.

If I were you, I would consider using a pair of Era 100s instead and placing them at these locations in red:

 

Thanks, I appreciate you for replying. However, I'm more wondering about the green option itself with the 300s, Would it be a total waste? Can you please explain why?

It wouldn’t be a waste. I think they can still sound good. I am a little concerned about the uneven distances of the back wall and whether or not the surround audio will sound imbalanced. I’m also not a fan of placing the surround speakers that high. It’s usually recommended to keep them around ear level.

Thanks, I see your point. On the good side - I got a comment on a similar Facebook post that Trueplay will resolve the uneven distance issues (from a guy that said to have a similar setup in terms of uneven distances).

And I’m with you on the high placement… But let me tell you, my wife had to make a lot of giving up so we can make this purchase happen… So I need to make some giving up too That’s why any other solution but mounting them high & back won’t work for me. I posted this post mainly for confirmation that buying them and placing them there won’t be a total waste… Hoping that perhaps someone can think of something I didn’t think of that would also be acceptable in my situation.

If you or someone else has any more insights or ideas - please, be my guest!

Again, thank you!

Getting power to those locations will be a challenge. 

Hey - thanks for the reply! Actually, not that of a challenge. The wall is a drywall and behind it I have wiring. Just need to install a power socket to it.
I was fearing that wall installation would be the big challenge, but I found the Sanus Wall Mounts which are drywall compatible.