Tonearm Geometry and Setup


While this subject matter seems to be of 'crucial importance' for our hobby our discussion about this issue is fragmentary and split over different threads in our forum. As if we are talking about some 'abandoned child' that nobody wants. I thought that this 'child' needs its 'own home' in metaphorical sense or its own thread in the
usual sense. While tonearm geometry seems to be very 'simple' in mathematical sense there are many unresolved questions in the actual sence.
My question for the start of this thread is:
'why are we not free to choose the zero points on the record radius independant of the tonearm used?'

Regards,
128x128nandric
I thought that these were the product of the width of the record, which is a constant, the length of the tone arm, which varies, and the chosen formula [Loftgren etc] for producing the least distortion. This would appear to offer zero degrees of freedom so I must not have understood the question.
Stanwal, rather than not understanding the question, I think perhaps you answered it. The zero points are, as I understand it, calculated as you say -- so we are only free to "pick" a zero point to the extent we are "free" to pick one of the several formulas intended to identify the zero points leading to least distortion. True?
Dear Rdavwhitaker, true. No the question is, what are the best points and what does mean "least distortion"..... least distortion where on the records radius .... the groove is not homogenous, as the radius is decreasing ever more with lesser distance to the label and thus the situation for the stereo stylus is getting more and more "unbalanced.
Cheers,
D.
I am of course not (pre)supposed to answer my own question
but considering Stanwals comment I need to put my question more clearly. The context is this: 'we', or at least I, got the impression that I can choose the 'zero points' depending on which part of the LP I want the least distortion. Baerwald is about the best solution for the whole record radius (aka 'the average') while the other provide better solution for specific part(s) of the record. Ie Stanwals 'least destortion' in general will not
do. This thread as well as the question of 'choice' is caused by some remarks by Dertonarm in the 'Copernican thread'.

Regards,