[Russell Dawkins]

It may have been Albert Von Schweikert that said to place the speakers at the separation distance that the mics were originally placed,

Then I guess for a Blumlein crossed figure of eight recording the speakers need to be dipoles placed on top of each other and faced out at 90º angles to each other, and for an ORTF recording, the speakers need to be 17 cm apart.

I'm sure there are a lot of factors to consider...

[JLM]

As far as possible (side walls reflect too much and center of soundstage falls apart). 

[Wind Chaser]

...distance between speakers for best sound stage and stereo imaging...

There's something else you have to consider in order to achieve your goal; and that is the distance of your ears from, or in relation to the distance between the speakers.

I prefer to spread my speakers as far apart as possible and sit slightly closer, rather than the equilateral triangle. In my current room, that translates into 9 feet apart with my ears back eight feet.

The more space between the speakers the better, especially when they are at least 4' away from the front wall. If the room is big enough, I'll pull them much further out into the room, 10' or even 12' - it makes a big difference. The more breathing room they have, the more they open up.

Side walls have to be considered as well. I prefer to have my speakers at least 3' away from the nearest side wall.  Too close to the walls and you lose that openness.

If you have a vaulted ceiling that can be a good thing, depending on the room.

[Don_S]

As far as possible (side walls reflect too much and center of soundstage falls apart).

 

[FullRangeMan]

Hi Guys
I thought i start this topic to get your views/opinions on the best distance between speakers for best sound stage and stereo imaging,I see all kinds of distances and wonder which is the best one,anyway all opinons welcome.

Soundstage size and sound image intensity are conflicting parameters like day and night.
The more distant the speakers (big soundstage) the weaker the intensity of instrumental image.

[STEREOmole]

Then I guess for a Blumlein crossed figure of eight recording the speakers need to be dipoles placed on top of each other and faced out at 90º angles to each other, and for an ORTF recording, the speakers need to be 17 cm apart.

I'm sure there are a lot of factors to consider...

Ha ha!  I was going to make that same point!
My placement has always had more to do with room restrictions and my wife, than optimum sound.  I place them where they sound the best (slightly toed in) within the limitations of the room and furniture.

[Folsom]

Soundstage size and sound image intensity are conflicting parameters like day and night.
The more distant the speakers (big soundstage) the weaker the intensity of instrumental image.

Pricelsy why I do it as I do.