vandersteen 2ce sig ii listening distance and tilt

You don't do it like that. Place your speakers and your listening chair where you need them to be in your room, and then sit in the chair and run a tape measure to get the distance between your head to the center of your speakers. It's not necessary to form an equilateral triangle. That's the reason for setting the back tilt in the first place.It will vary depending on how far you sit from the speaker. Also, 9 feet apart is probably a bit too far. Start off with the speakers 6 feet apart, from inside edge to inside edge. Move them further apart a little at a time and stop where they sound best. I think I have mine at 7 feet. With good electronics, your speakers can image beyond the outside edge of your speakers.

It takes a little while to set them up the first time. After that its easy.

I forgot to mention, that if the speakers are new, then you probably need to let them break in, and the contour controls should be set to flat.