Speaker distance and tow in?????/

Here's an article we wrote on this subject that might be helpful.
Loudspeaker Placement

Rives, Nice article.

I've a question regarding the positioning of speakers near a side wall as it relates to 1st reflections, soundstaging, and sweetspot. Its based on something I have done "successfully" on quite a few occasions when I was using dynamic speakers with a wide and smooth radiation pattern (which usually means hot on axis highs).

Is there a down side, acoustically, to positioning the speakers close to the side walls and toeing them in so the the axis crosses in front of your listening position on the same corresponding angle as they would if they were toed in to have the axis point straight ahead or behind the listening position?

When I have done this it seems to have minimized the need for treatments to the side walls, maximized the sound stage width, and as an extra benefit for those in need, widened the sweet spot substantially, that is a person sitting in front of either speaker would still get usable stereo imaging with good (not great) center focusing. Unlike when pointed straight ahead the image doesn't just collapse into the closest speaker.

Anyone else ever played with this?

In my experiments, it seems that pulling the speakers off the wall really increases the depth of your soundstage.

On one of these august sites I read advice on toe-in that I've found works for my KEF 104/2s: Aim the speakers at half the distance between the prime listening location and the rear wall.

My room is about 14' by 19', and the front of LR speakers are about 4' from the wall behind and 3' from wall to the side. The listening positions are about 3/5 of the room length and centered laterally.

db

The best rule of thumb I know of is the speakers and seating should both be at i/3 the room depth. If that is not possible 1/5, 1/3 works. The next would be 1/7….
In you 18x30 room I assume your speakers are on the short wall, thus you have a little under five feet to each side wall? If this is true the 1/3 dimension is 10’. Meaning the best would be to start 10‘ to the speakers and 10 more to the chair. As you said, this is not practical. The next best is the speakers at 6 feet from the back wall to the tweeter face. This would still provide adequate soundstage depth. If this is not possible, the 1/7th dimension is 4.2 feet. If you need to go even closer keep trying the odd factor of dimension.
As per toe in, start straight out and test it. Keep toeing in until the center image becomes clear and defined. Small amounts from that point will allow you to tune it closer, making a solo vocalist’s mouth appear the correct size.