Speaker Positioning

Most of these 1/3 rules, 1/5 rules, etc. are nothing more than avoidance of room nodes.  It's 2020, we don't have to use simple rules any more.  They don't account well for room size, aesthetics, etc.   When you have simple online tools like amroc, it does not make sense to use "rules" or rudimentary calculators.

https://amcoustics.com/tools/amroc

I would suggest taking into account the frequency response of your mains and where they are placed.


@sj00884, what you are asking is possible, you can get that from impulse responses with reflections.

Here is the Cardas calculator that’s mentioned.
http://www.cardas.com/room_setup_calculators.php

Not ideal for a living space since you will be placing speakers out in the room. Naturally, your ears will tell you what sounds best, but it does give you a good starting point. Getting speakers 4-6’ out allows your speaker to sound its best.

The laser exact measurement doesn't mean anything for some industry vets who go by ear, and will have speakers positioned uneven due to gear channel imbalance. Setting them up like focusing  binoculars to "lock" a balanced sound can leave one speaker pushed forward of the other. Looks odd, but if you're going for sound, that's what it takes. I've participated in moving speakers/subs and heard the results.

My personal system/ears follow the Cardas guide.

So lots of potential solutions and even more information to fiddle with.   Anticipate a relo further form the back wall, may not be able to accommodate side wall optimization but it seems like always from walls is a constant.  
The sweet spot/toe in variable seems to lend itself to almost as much debate; do you adjust sweetness to a single location, or do you compromise to expand the geography? Another personal preference no doubt.

thanks again to everyone who took the time.

Other than following advice on how not to blow something up or catch fire, I take everything put it in a jar and shake well. Dump the mess on the floor and take a little from here, a pinch there, then let your ears decide.

LOL T-Jockey! That is exactly what I am doing, somewhere between 1/8-1/5, tweeter height, etc. etc. etc.  all great free things to try!

I did purchase the cheap Bosch laser rangefinder.  If only I could find a good used mass spectrometer. 8)