Bristol that sounds like a fair distance apart. As long as you are sitting 5 feet from each speaker too. That would be the only way it would work better and both facing in at 30 degrees. You would have to be monitoring a little louder to hear them better and when the size of the triangle gets bigger the room has to be more involved to a certain extent.
 
I have just kept my setup down to the 1.1 meters for me. It all seems to work rather well at that sort of distance. My speakers are also on concrete stands and it makes quite a difference. The stands seem to focus the sound out a little more directly at you thereby reinforcing that centre phantom image even more. When the distance is good, panning movemets sound even and smoother as well.

This is a great thread. So much is made (and rightly so) of room shape/treatments etc, that this is a barely mentioned aspect of achieving a balanced environment for your mixing. It wouldn't surprise me if a large percentage of us considered the surround sound set up and speaker placement for our Tv/Dvd players more than we do for our studio speakers.
That would probably include me....*Rushes off to find tape measure*

Bibs

I know what the "experts" say about monitor distances and triangles with the listening position......but I fall into the large category which requires me to place my monitors where I can, regardless of the "rules" I break in the process.
 

 
While this photo is an older photo of my studio, the monitors are still in the same place... and yeah the right side monitor is inside an enclosed box for all intents and purposes. I gotta do what I gotta do. The current studio has the viewing monitor setting where the laptop is, and the CPU is under the desk beside the Cerwin Vega stereo speaker.
 
Listen to the mixes I do and you will hear that the un-approved set up I use is not a major handicap to me.
 
By all means, if you have the space to set up a studio properly, do so..... but don't let a lack of space put a kink in your plans.
 
These speakers are approx 50" (4.1') apart. I too, very often in the mixing stages, push back, and listen with eyes closed as Bitflipper mentioned.

I have a little article section on my website to help my clients with common questions.  One of them is about speaker types, placement, and setup.  It is mainly aimed at living room and common home stereo setup, but it addresses the topic of this thread I think. 
 
http://www.rumleymusic.com/mgtar/Speakers.html

How far apart would you say these were?
 
About 50"? Maybe slightly less?
 

Your mains look a little far apart to me. You are in a good position to do the sliding thing of bringing your monitors closer together when listening to a mono source. Check for phantom ghost appearance and breakup. See post #7
 
What I would do with the two little speakers is feed them both with the L+R signal if you can. And split them up and get them off the main speaker shelf. You will have more room to bring the mains inward and still setup your screen nicely in between.
 
I have got the two small mono speakers at the back of my keyboard controllers facing up to me so I can still hear the mix no matter where I turn and play. This is important. You play better especially with the click if you can hear the mix anywhere in the room nicely. They need very little power to be heard easily. I also feed mine through a crossover and roll off everything below 120Hz. That way they don't fart when up loud and but you never need them loud anyway.
 
You can still use them as a reference to mix on no matter where they are in the room too. The more distant they are can be a help as well for mix checking. When I am doing important mixes and I know I am going to spend some time working on one, I grab one of them which is on a long cable and sit it directly in front of me either on the table or in between the monitors. I leave them both in mono most of the time, I find it more useful that way. At low level I sometimes put the bass end back into the speaker (bypass crossover)

Duplicated stupid forum software!!

Hey Jeff, thanks for that - but those aren't my monitors!
 
That was a picture I lifted off the web somewhere, but your thoughts on placement are still valid, just not applicable to me!

I'm guessing 49.68".
 
19" + 3/4" + 19" + 3/4" + 19" - 8.82" = 49.68"
 
 
Following the convention of defining the sweet spot at the apogee of a equilateral triangle:
 
 
Pythagorean Theorem:
X² + 24.84"² = 49.68"²
 
X² = 2468.1024" - 617.0256" = 1851.0768"
 
X = 43.02414"
 
 
Trigonometry:
cos 30* x 49.48" = 43.02414"
 
The *sweet spot* is 43.02414" from a point located halfway between the two speakers and measured perpendicular to the line formed by the placement of the two speakers.
 
 
 
 
A more compelling issue with that setup is the placement of the speakers against the rear wall.
 
That sort of placement guarantees that the end result will sound more like a bad setup and less like any particular speaker model.
 
 
best regards,
mike