Dear friends: Do you know why the tonearm denomination: 12", 10", 9", etc, etc? what those numbers means?
Well, as you all know is the tonearm effective length this is: the distance between the stylus and the center of the pivot/flucrum/bearing and IMHO this is the foundation of the tonearm calculations parameters.
When we want to design a tonearm ( between other things ) we first determine/think in those 12"-10"-9" numbers ( we are not thinking on overhang or pivot to spindle numbers. ) and is this " number " ( effective length + innermost/ outermost groove radius. ) the one that we introduce in the Baerwald/Loefgren/etc formula to obtain: overhang, offset angle, pivot to spindle distance and null points.
If we change the overhang ( like in the Graham example that " play " between Baerwald and Lofgren. ) alone then we are changing the " foundation " ( effective length ), so this practice is not correct, you can do it and you can do anything you want but that does not means is correct: is wrong.
Every time we change the " foundation " number ( effective length. ) change too the other tonearm parameters.
I'm not talking here if the sound likes you or not I'm only talking of what is right and what is wrong.
We can put an example using first Baerwald:
say 250mm on EL: offset angular, 21.949 degrees; overhang, 16.502mm; P to S, 233.50mm.
now 258mm on EL: offset angular, 21.235 degrees; overhang, 15.956mm; P to S, 242.04mm
Loefgren on 250mm: offset angular, 21.949 degrees; overhang, 16.967mm; P to S, 233.03mm
and in 258mm: offset angular, 21.235 degrees; overhang, 16.404mm; P to S, 241.60mm
Well, it seems to me that that tonearm effective length is in reality the foundation to calculate those critical tonerm parameters.
We have to take care on what we do because " sometimes " we achieve a different target that what we want.
Regards and enjoy the music.
Raul.