Tonearm effective mass

Doug: Thanks for that information. It is both counterintuitive and very relavant to me at this time as I am in the process of doing a tonearm upgrade and one of the goals is to increase effective mass of the tonearm (cartridge is a wood bodied Denon 103R). I am looking at changing out the stock headshell on the new tonearm (stock headshell weighs about 6-7 grams) with an aftermarket headshell that weighs 16 grams.

I've been assured by someone who owns the same tonearm that the stock counterweight on the arm will balance out the cartridge and heavier headshell. There is also an optional heavier counterweight available for the arm to balance out heavier cartridges. I'm assuming, though, from what you say, that the lighter (stock) counterweight in this situation is going to result in higher effective mass.

Would you concur with that? Thanks in advance.

Thanks again Doug (and Quiddity). I understand (now) that it's a given that the heavier headshell will have a much greater effect on increasing mass than messing with counterweights.

It was interesting to me that a lighter counterweight pushed out further from the pivot might have as much (or greater) effect in increasing or maintaining a given effective mass than a heavier counterweight balancing the same cartridge closer to the pivot point.

Following this, my next question is this: given that a lighter counterweight is capable of balancing out the same cartridge (but obviously further back from the pivot) that a more substantial counterweight can, would there be any sonic advantage to using the heavier countweight mounted closer to the pivot assuming the effective mass is approximately the same? Would there be a sonic advantage or improvement using the heavier counterweight closer to the pivot point?

Does anyone have any experience with this or any ideas as to whether one approach would be better from a sound perspective than the other?