If curious, this paper on Tonearm Mechanics does a pretty good derivation of the resonance and the effects of mass.
http://www.cartchunk.org/audiotopics/ToneArmMechanics.pdf
http://www.cartchunk.org/audiotopics/ToneArmMechanics.pdf
- ...
- 42 posts total
It's essentially a problem in integral calculus.I have and will continue to align myself with what Raul and cleeds have said, which is what I also have written, in response to BR3098. Adding mass at the headshell has the largest possible relative effect on effective mass, compared to adding mass anywhere closer to the fulcrum or pivot. The effect of added mass on total effective mass is lessened as one approaches the pivot. As we have already noted, adding mass, because it increases effective mass and would have the tendency to reduce the resonant frequency in magnitude, but not necessarily in amplitude, which would depend more on damping, stiffness, materials used, etc. BR3098, forgive me for being overly sensitive and for misinterpreting your earlier remark. In any case, I was not in any way upset or angry, just confused. |
@lewm @cleeds Gents, my diatribes were only in regard to the OPs question regarding resonance. Obviously adding mass further out from the fulcrum is the most effective use of mass, but (as I described) is problematic for mechanical reasons and is not the most effective method of reducing resonance amplitude. Calculating the change in resonance magnitude will require additional information not provided. Now if, as lewm proposed, we are allowing the alteration of other factors including "damping, stiffness, materials used" then all bets are off. I hadn't realized that we were discussing a tonearm with an infinite k value. 😁 |
TL;DR ... One point I’d make is that the numbers are a good staring point, but will take you only so far. I’d give serious credence to "tribal knowledge", trying the combination out, as well as the advice of a trusted dealer. I took the compliance calculator off our website because I was seeing too many people treating it as gospel instead of as a guideline. A customer brought over a Van den Hul cartridge to test with a Kuzma 4Point (11"). Frankly (from the compliance and tracking force recommendation), I didn’t think this would be a good match, but that’s why you try things. I documented that session over here https://galibierdesign.com/van-den-hul-demo/ I suspect the Kuzma’s phenomenally, low friction bearing plays a strong part in this, as it’s a wonderful combination. ... Thom @ Galibier Design |
- 42 posts total