[RoadTripper]

Is there some consensus on whether or not it is best practice to situate one's speakers in such a way that the plane of the speakers is parallel to the back wall and perpendicular to the side walls?

Because of the nature of my newly acquired sound "cave" it looks like I won't be able to set my speakers up that way. The speakers are open baffle as well which makes placement even more critical, possibly. One speaker will be farther out into the room than the other one, which will be closer to both the side wall and the back wall.

Will this screw up anything - such as 3D imaging etc.?

[FullRangeMan]

Seems it will imo, you have the room floor plan?

[RoadTripper]

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[youngho]

Could you change the position more like this?

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The pole would be behind you, the speakers would be set up in an equilateral triangle (sorry, I have no idea about your dimensions), and the open baffle suggests a dipole radiation pattern, significantly reducing the sidewall reflections overall due to the relative null to the sides of the speakers but needing more distance to the wall behind the speakers (you could add diffusion to this wall).

Take a look here: http://linkwitzlab.com/rooms.htm#D

[youngho]

Alternatively, you could place the speakers so that the pole is between them (and in their nulls), but this would put the listening position closer to the rear wall, which would further benefit from more absorption.

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[RoadTripper]

Thanks. That layout has always been my sort of default option. That makes it very nearfield. The dimensions are 24X17.

Even with it like this (top speaker 3 ft. from both side and back wall) it is less nearfield but still would have my ears about 8 feet from the speakers (maybe less).

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Maybe nearfield isn't so bad, but these speakers are gonna be GR Research Super 7s. (i.e. pretty big)

My question, though, is how much sound degradation will happen with the rotated layout?

[RoadTripper]

By "that layout" I was referring to your initial drawing. The pole causes a second problem which is a TV, although I may have to forego that entirely.

[youngho]

Even with it like this (top speaker 3 ft. from both side and back wall) it is less nearfield but still would have my ears about 8 feet from the speakers (maybe less).
...
My question, though, is how much sound degradation will happen with the rotated layout?

8 feet isn't too bad. A little further from the back wall would be better, but a little closer to the sidewall would be okay. You could also flip the default layout so that the speakers are closer to the door.

I can't say about how much, but rotated looks me that it puts you closer to the corner behind the listening position, so you'd want to have a good amount of absorption there, and I would imagine that stereo imaging would be adversely affected by the difference in relative balance of both frequency response (difference in proximity to the boundaries) and early reflections (especially from the wall located to the left of the listening position). I don't know how the difference in the late reflections would affect things.

In general, if you value stereo imaging, I believe that it's commonly accepted that it is helpful to have relative acoustic symmetry. See here: http://linkwitzlab.com/listening_room.htm
"The specifics of the phantom acoustic scene that is rendered by a pair of loudspeakers and perceived by a listener's brain depend upon the radiation characteristics of the loudspeakers, their location in the room, the reflective, diffusive and absorptive properties of the room and the listener's location. The first requirement is for lateral symmetry of the loudspeaker and listener setup with respect to large reflecting surfaces. Secondly, the loudspeakers must be placed at some minimum distance from those large surfaces in order to delay specular reflections by more than 6 ms."

[FullRangeMan]

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This layout looks good with 3ft from the wall at first glance imo.
If 5 or 6 ft better.

[Big Red Machine]

Replace the pole with two and site between them.

I paid $500 to an engineer who told me I needed to reinforce my steel beam with welded sheets to move a pole less then 3 feet outward. What a waste. I put in a new pole and raised it and lowered the old one and had no issues. It's easier than you think.

[guest61169]

How thick is the pole?  Is it round or square?

[RoadTripper]

4 inches, round. I want to remove the pole and put two of them in, one near each wall. The pole is reinforcing a beam which holds up my kitchen.

[Armaegis]

4 inches, round. I want to remove the pole and put two of them in, one near each wall. The pole is reinforcing a beam which holds up my kitchen.

The engineer in me says don't do that due to structural concerns, but no one listens to us engineers.

What you really should do though is check with your city zoning/permit/whatever office if you're even allowed to touch that pole, otherwise you might violate the insurance of your home or face some other penalty.

[Big Red Machine]

4 inches, round. I want to remove the pole and put two of them in, one near each wall. The pole is reinforcing a beam which holds up my kitchen.

Steel beam or laminated wood beam? Steel are usually way overdesigned. The issue to watch is the floor.  My guess is your footer under the beam might be running front to back in the room (90 degress to the new poles). If you spread out the poles you may only be on 4 inches of concrete floor and not a footer which is deeper and wider. If the room is not finished now then cutting 2 squares and filling them as footers would be the ideal.
If you measure your beam you can look up the span it is designed to handle.