Presents? Do I win?
If box cabinet, use counter weight on top of the cabinet. Suppose to help imaging.
If you are using spikes, keep in mind what they are supposed to do. Go thru carpet/pad and stick firmly in the subfloor. It serves two purposes. Solid platform for generating sound waves and dampening cabinet vibration. When you build a foundation, build for those goals.
I understand not wanting to use the subfloor as the primary dampening point. Vibrations come in to the cabinet as well. Now, if you need to have the spike as the mechanism to transfer the mechanical energy, is a single point the best dispersal contact method for low frequency energy? Would brass be a better material to use for the spike? If the spike is setting on hard material, how effective is the energy transfer? A thread to thread connection into the dampening material would transfer better.
Do the cabinet designs try to build vibration directing technology to transfer energy from all points within the cabinet to the thread inserts? Or does the cabinet material do this? I can see real issues with a tuned cabinet material also transfering mechanical energy away from the driver. Perhaps the drivers could be mounted to a brass frame isolated from the cabinet except in the resonating points. The base would have the thread inserts in the frame for direct contact to the spikes.
I have not tried this yet, but, would a metal thread to a broader wood thread on the bottom into wood block directly (no metal insert)/ dampening material/wood block wood thread thread to spiked subfloor minimize reverse contamination? The wood would have to be dense enough to support the weight of the speaker. The thread would have to be sharp and the insertion slow to minimize damage to the thread contact surface (maximizing contact). Too fast would burn the wood and introduce a harder contact point.
Just some Sunday morning coffee thoughts. May not be worth a crap, but hey, it might. Yeah, thats it.