Isolation Cones/Bearings placement on CD Transport

There are no exact measurements in placing cones or bearings under a component. Many manufactures do suggest an initial placement, and the rest is up to your listening skills. I have found that a slight movement in placement of a cone can change the soundstage and imaging.

I'm not sure about isolation bearings, but with spikes/cones/points, the ideal location is to place the 'vibration control object' dirlectly underneath the spindle, and also directly underneath the power supply. And for amps and preamps, the ideal location is always under the power supplies whenever possible.

I believe that weight distribution of the chassis does not really matter as much except in the case of safety where the component can more easily lose it's balance.

-IMO

Based on my experience with Golden Sound DH Cones. Two cones in the front will increase the width of the sweet spot. One cone in the front will decrease the width of the sweet spot, however, increase the depth of the sound stage.
Generally, I like one cone in the front pointy side up and two cones in the back pointy side down.

Put your main finger on the middle cone and move it topside. Do the opposite for bearings.

I second Stehno's post! Thats always been my understanding on placement too.