My new Mitsubishi 46" 16:9 had some "speed bumps" about 1/3 up from the bottom and 1/3 down from the top. I would notice these during certain scenes in movies, mainly when the camera was panning up or down a mountain or big object. No one else noticed it, but it bugged me. I went into the 64-user convergence grid and measured off some of the grid sectors and sure enough these areas had compressed sectors horziontally across the entire TV. So with some help from the guys over at the SPot, I built the following geometry grid template:
I used a piece of plexy glass, cut it to fit the screen size, took some measurements, did some calcs and drew the grid on the plexy-glass with a fine point black marker. I then placed my grid on the TV screen and taped it into place. I then went into the service menu to the fine green grid (this controls the actual grid points of the TV) and moved the points to match my grid. I then saved the new grid as the factory default. It is amazing how many points were even just a little off besides my two bad areas. The grid template worked wonders for my picture.
I also turned off SVM, did an electrical focus (this was also a substantial change in picture quality) and then redid the 64-point user convergence.
All I can say is from 6 weeks ago out of the box to now, after some tweaking, this TV is absolutey beautiful.
The 3 tweaks above, IMO, were just as important as calibrating with AVIA.