It’s best to have the surrounds at ear level, but I have seen people have them in similar positions and been happy with it. It’s all about what sounds good to you. Make sure to use trueplay, if at all possible.

Yeah, I keep reading different things. There's people saying at ear level like yourself, 2 feet above your head, 5-7 feet above your head, tilted forward, tilted towards the viewing area - it's crazy how different some of these opinions are. 

The problem is, I don't want to start drilling holes in my wall for mounting if where I'm positioning them isn't a good idea - as you can tell this is all new to me.

You can see by the pic that one speaker would be significantly further away than the other - do you think that would be an issue at all or something Trueplay could pick up on?

For a proper setup it would be ear level as that is how it is meant to be heard. However, everyone has their own preferences or maybe isn’t able to based on the room layout. I placed one beside the couch, on one end of the room, and the other beside the dining table on the other side (in a combo living/dining area). It would be pretty close to the distance that you are trying, maybe slightly further apart even, and trueplay did a fantastic job at pulling everything together. 

See, I've also read that because the rear speakers are used for ambience during tv/film they don't need to be directly at ear level? 

Sorry to question everything here but I've read a lot of differing opinions. 

They are used for things like ambience, sound effects, music etc. that are mixed into those rear channels. It is meant to sound like it is coming from just behind you, and technically speaking it should be just above ear level as placing it too high could lead to it sounding unnatural. Those others would be based on opinion, but again it is a matter of taste. Ultimately, it comes down to what sounds good to you but if unsure then I would see if you can get close to that without drilling to see if you’re comfortable with it.

https://www.dolby.com/us/en/guide/surround-sound-speaker-setup/5-1-setup.html

I haven't quite got the room behind me to have the speakers that far back - the sofa is practically against the wall with a gap of around 10 inches for a stand and little else - but I'll see what I can come up with. 

Thanks a lot for your help

Not a problem. Best of luck :)

I would do the stand behind your couch as the first option.  Although stands do cost more than mounts, depending on options, they aren’t going to be as permanent as the mounts.  You can always change your mind.  

I personally have mine at early level about a foot or so behind my head.  Not ideal, but works just fine.

I bought these and I think they are great.  Very solid.  Aesthetically fine.  Bases are very heavy.  Follow instructions for installation.  https://www.sanus.com/en_US/products/speaker-stands/wss22/

I got a similar setup and tried different positions of the surround speakers, including the upwards-slightly-to-the rear position which is suggested by Dolby. The problem I found with each of these is that, because the speakers will be very close, you don't get a sense of ambient sound. It's more like something coming from the left OR right, depending on where you sit on the couch.

So, what I tried is placing the surround speakers on their back facing up. And that really works well for me. The sound bounces from the walls and ceiling, proving an ambient sound which is not too directional while preserving enough orientation when it really matters.
 

Anyway, this is easy to try out. Hope it helps!

Did you go with placing them high up on the wall? I have the same conundrum. My back wall is a couple of feet from the back of the sofa so I could use stands but I would prefer to put them on the wall like you have suggested in your pic. I'm interested to know of movies would still sound good?

I am looking at either the Sonos stands or the Sonos wall mounts, if anyone has any experience with these.

Thanks.