Like Dave says in his descriptions of the Sumiko Master Set procedure, getting the focus right in bass, mid, treble and everything in between is very difficult but achievable. If you want to DIY, you can use mono recordings to assist in getting balance and focus correct. In my particular setup, when my Wilsons were in the incorrect position, the bass would shift around 1 foot to the left of center even with mono recordings. Or the bass would sound like it was a coming from a different speaker and not contiguous with the rest of the music. I guess this is the result of an unlevel frequency response caused by the cancellation or doubling effect of sound "nodes" occurring in the room.
However once I hit that sweet spot, suddenly, the image became dead center, the bass, mid, treble and all in between grouped together in the center and played as one (remember it's a mono recording, I use one of Ella Fitzgerald's earlier works). Forget testing with stereo recordings, there are just too many variables and unknowns.
Don't forget that your sitting location is important too. You have to choose your favourite sitting location and then optimise the speaker setup for that one location. I find that speaker setup is dependent on the sitting location and even hifi components. I had my sofa too close to the back wall by 4 inches and just couldn't get the speaker focus right. When I moved the sofa forward, the focus eventually snapped into place.
If this sounds all too complicated, just call someone and pay for a proper setup. For me, it's part of the hobby and learning process.
