Jackmon

I own a pair of Chorus IIs and have them sitting on mid-length pile carpet over a concrete slab foundation. I would like to support these by sitting them on suspension cones (spikes) to directly contact the concrete slab. My questions: What is the best configuration for cones on each Chorus II speaker (how many and where placed)? Is it necessary to drill holes in the speaker cabinet and sink threaded inserts? Is brass the best cone material?