Azimuth observations and importance

After adjusting azimuth with a Fozgometer loaned to me, the following is what I observed. Individually, these changes were subtle although noticeable. The combined effect however, was significant to the overall presentation.

Imaging improved.

Vocals became more focused, not as big and wide as before.

Instruments more detailed with greater air. Location is more precise.

Tighter bass versus the slightly lingering bass notes previously.

Better top to bottom detail and clarity.

I never realized how important correct azimuth adjustment is and this exercise was quite a learning experience for me. Thinking I was correctly adjusting azimuth by visually setting the headshell as level as possible was a reasonable but flawed attempt.

I have found at least two stylus issues that if present will affect azimuth and sound.

1) A straight cantilever that is twisted left or right changes the attitude of the diamond and its relationship to the groove. By twisted I mean the cantilever has rotated on its own axis. This one is very difficult to see without appropriate magnification.

2) A cantilever that is canted to the left or right a degree or more but is still straight, not bent. It points left or right probably because it was not centered correctly when the cantilever was installed. It also changes the attitude of the diamond.

What is probably basic and common knowledge to everyone here is something I have just been enlightened about after giving it very little thought. I am now convinced that accurate azimuth is a required step in the turntable set up process and I will be giving full attention to this part of the equation.

No more guesswork and eyeballing which I am embarrassed to say was the norm. Doug
I now tested the Fozgometer. Yes - it works. Also the channel balancing is a good feature. But - as I assumed - it is not very precise. The needle of the meter scale is moving in between 2 -5 gradations during the reading of the signal from the delivered TestLp. Even Musical Surroundings admits that a 12.5% deviance is acceptable.

So it is a good tool maybe for the beginner or people who never cared about the Azimuth. And it gives a good feeling for not so much money...
Below are results I achieved with my VPI Classic 3 and Dynavector XX-2 MKII. In the specification the XX-2 MKII channel balance is specified as 1 db at 1khz. The Cartridge was aligned with a MINTLP protractor custom made by YIP for the table. I have done multiple alignments with the Mintlp, and I spent some time getting it right on with a 10x loupe. I used the multimeter method at the preamp output for the test and a test record which has right and left tracks only. As you can see, with a perfectly flat headshell, my total crosstalk was -55.64db with a separation of 3.15db, which is over the 1 db spec. I needed to get the right channel with less crosstalk. I tried tilting towards the left channel, which did not lower the right channel crosstalk, it actually increased it. When tilting towards the right channel the crosstalk between the 2 channels started to converge. On the last measurement you can see I was able to achieve a total combined crosstalk of -58.94 with a separation of 0db with a 0.94 degree tilt towards the right channel. Of interest is the total combined crosstalk went down by 3.41db by tilting 0.94 degrees and the left channel was not affected at all relative to the headshell flat crosstalk. The crosstalk remained at -29.47, but I was able to decrease the right channel be 3.41 db.

Channel V1 V2 crosstalk (db) Channel V1 V2 crosstalk (db) Azimuth (degrees) total separation
Left 4.72 0.16 -29.40 Right 4.72 0.25 -25.52 0.19 Tilt Left channel -54.92 3.88
Left 4.69 0.20 -27.40 Right 4.69 0.27 -24.80 0.19 Tilt Left channel -52.20 2.61
Left 4.72 0.19 -27.90 Right 4.72 0.28 -24.54 0.75 Tilt Left channel -52.44 3.37
Left 4.72 0.16 -29.40 Right 4.72 0.23 -26.24 0.00 Flat headshell -55.64 3.15
Left 4.69 0.16 -29.34 Right 4.69 0.23 -26.19 0.38 Tilt right channel -55.53 3.15
Left 4.72 0.15 -29.96 Right 4.72 0.21 -27.03 0.38 Tilt right channel -56.99 2.92
Left 4.72 0.16 -29.40 Right 4.72 0.20 -27.46 0.56 Tilt right channel -56.85 1.94
Left 7.14 0.22 -30.23 Right 7.14 0.31 -27.25 0.56 Tilt right channel -57.47 2.98
Left 7.14 0.22 -30.23 Right 7.14 0.29 -27.83 0.75 Tilt right channel -58.05 2.40
Left 7.14 0.24 -29.47 Right 7.14 0.24 -29.47 0.94 Tilt right channel -58.94 0.00
does anyone use shims (spacers) for azimuth adjustment on a non-adjustable tonearm? does anyone make a set thin enough for this purpose?
My opinion on azimuth is that it's always a compromise, no matter how long you agonize over it. I set the arm up to look balanced and see how it sounds and adjust by ear if necessary. I've never really believed the compromise you spend ten minutes on is much worse than the one you agonize for weeks over. Having said that, I'll soon have a Reed 3P to play with. Maybe the fine adjustments on the fly will change my mind on this. Meanwhile, my system sounds great without multimeters, filters or fozgowhatevers.
I realize I'll likely be blasted for the above post but, as great as vinyl is, it's not a perfect playback medium. Do we really believe all records are cut the same? Even from the beginning of one side to the end can vary. The perfect adjustment for one LP is great as long as you only play that LP. Where is the line drawn between good setup and just dwelling on minutia?