Alec124c41 wrote:I think the heavier headshell being at the long end of the arm will make more difference than adding a bit of weight to the CW and being able to use the VTF slider will take away.
I like to play with things more than numbers.
It's still OK to play with both
.............! Look, by definition, Tonearm Effective Mass is an analytical quantity. It doesn't respond very well to intuition, unless you're wired up like Euler back in the 18th century !
It's purpose is defeated by evaluating effects of changes incorrectly. And bizarre to then wonder at the mysteries of how imperical results differ. Unfortunately there's pretty widespread misunderstanding that often contributes.
In fact, counterweight position can make a big enough difference to tonearm effective mass to take notice of. Even a few mm change. It's effect is proportional to square
of distance from the pivot. Not intuitive.
And a lighter counterweight actually contributes more to effective tonearm mass than a heavy one. In balance. Again, not intuitive.
There's some dodgy advice about, unfortunately.
These are common 'errors' :
1. Underestimating effect of headshell/cartridge mass changes
2. Not taking into account VTF setting
3. Not evaluating cartridge compliance correctly
4. Getting direction of counterweight mass change effects reversed
As already posted, errors can accumulate and become significant.
I wouldn't blame anyone for avoiding the nitty gritty. It's just a means to an end after all. I'd suggest using one of the calculators. But I would fully endorse putting effort into getting lf stability sorted out.
Alec124c41 wrote:I do things by trial and error.
Alec, you were about to try a heavier headshell and heavier counterweight together. With intent to increase total effective mass. But one increases, and one decreases effective mass. So it likely wouldn't have the desired result, and you'd never know why. And bas would invent some nonsense 'swinging dumbell' theory to 'explain' it.
But the combination would never have done what you'd intended as to total effective mass in the first place !
I trust you can see the problem !