Mdomnick ... I'm far from the most technically-able guy here ... but it seems to me that dampening a component's chasis through mass is a time-honored method of increasing its stability and resistance to movement through vibration. This is half of the "trick" of the VPI Magic Brick (the other half being RF absorption). I would think that, provided the combined weight of the component and the added mass are within the weight limits prescribed by the cones' or spikes' manufacturer, that the added mass should help. But your suspicion is correct -- there are very few concrete answers here, and the ultimate judges of the effectiveness of the tweak must be you and your ears.
Regards,
Paul
Regards,
Paul