cartiage for Kenwood L07D genuine tone arm

09-27-15: Jagdzaku
I received turntable last weekend
According to manual,I found the sub weight should be attached to the arm for the cartridge heavier than 9g
Does it change the effective tone arm mass?

No it doesn't. The effective mass is the mass or weight of the tonearm from its pivot to the headshell.

The extra counterweight enables you to balance a heavier cartridge. The counterweight doesn't add effective mass, but the cartridge does.

You have to factor in the weight of the cartridge plus teh tonearm's effective mass to arrive at the total effective mass.

thanks for reply
I might uses a EMT JSD or lyra kleos on it
hope they can work well

As with cartridge weight, the mass and distance of the counterweight from the pivot point certainly changes the effective mass/inertial mass of the combined system.

With all due respect to Johnny, and as Dave partly indicated, Johnny's response to the question about effective mass is incorrect on all counts. The effective mass is a function of the distribution of the mass of the tonearm from pivot to headshell, including the cartridge mass, (not just the total mass per se), which is why you cannot determine effective mass by simply weighing the tonearm, and the counter-weight also contributes to effective mass by a factor related to the square of the distance from the pivot point to the center of mass of the CW times the mass of the CW. Thus, the "subweight" increases effective mass on both counts; it shifts the center of mass of the total CW further away from the pivot and it adds to total mass. Apologies to Johnny...

Since the effective tone arm mass is not simple measurement
If I change a aftermarket headshell, how it will change? Can I ausume it add or decrease the difference only?