Room acoustics how ? My image is not centered

Look into to "Master Set Speaker Placement". Worth a try.

I presume you've done this, but if you haven't, measure to make sure the speakers are both the exact same distance from the center of the sweet spot.

If both side walls are quite reflective, then symmetry becomes more important. A strong early sidewall reflection can pull the image over to that side, so you want the early sidewall reflections to be either symmetrical or minimized.

Something that has not been studied much is the effect of a diffracting feature, like the vertical edge of a bookcase. A feature like that can mimic a secondary source, and pull the image over to that side.

Sometimes a "hole" (like a hallway) on one side of the room can pull the image towards that side. I do not know what mechanism is responsible for this, but I suspect the ear/brain system senses where the room boundaries are and might, under some circumstances, "mold" the perceived location of sound images accordingly.

Increased toe-in might be useful. The Merlins may not be the ideal candidates for this sort of setup, but (since it doesn't cost anything) you might try toeing them in severely, such that the axes criss-cross in front of the listening area. This will minimize early sidewall interaction.

Finally, if all else fails, try pulling the right speaker forward an inch or two. The slighlty earlier arrival time may offset whatever else is going on in your room.

Duke
dealer/manufacturer

I had a similar problem. My room is approx 13'x24' with 9 foot ceilings. My speakers are on one of the short walls. I have windows across one of the long sides of my room. The other long wall is drywall. I bought bookcases with glass doors for the side with the drywall so that the room was more balanced. This worked well and gave me a place for more books. I then used tube traps in the corners and put a very deeply carved wooden screen on the wall between the speakers. It is not perfect but it is a lot better than it was.

This is a link to my room photos:

http://www.photogan.co.il/audio/

side walls distance: 3.6m (11.8 feet)
front rear distance: 7.0m (22.9 feet)
ceiling height: 2.6m (8.5 feet)

thankyou

Acoustics can be very tricky, especially in asymmetrical rooms. Your room may look symmetrical, but the reflectance of glass and concrete at various frequencies is different—concrete being more linear—hence the bias in the image towards the left. The obvious thing to do is to use the balance control on your preamp. One half to one dB may be all it needs to center the image. Toe-in will help only for the high frequencies leaving mid to low still unbalanced.