DIY speaker isolation base for a wood floor


A definite sonic improvement in tightening up the bass. 
1. Start with 4 aluminum cones. I used some old Mod Squad Tip Toes.
2. 16x16 slab of granite.
3. 1/8 cork.
4. 1/2 inch neoprene rubber.
5. 1/8 cork.
6. Top with another 16x16 slab of granite.
7. Enclosed with a wood cradle to hide the mechanism.
  The granite is from scraps from a shop and was cheap. The added 1/4 inch of neoprene to 1/2 inch thickness did help. Let me hear your thoughts.
128x128blueranger
It sounds to me like your springs are more suitable for a 400 LB speaker. The spring rate of the system is the spring rate of a spring x the number of springs.
People in little places , and theres billions of them. Wouldnt fit these in there places . I feel a strong spousal dispute. 
blueranger,

Quick calc says your resonant frequency is about 6Hz. That does not feel right, but perhaps geoff can check my math. I was assuming 134lbs (2x granite + speakers). That do a pretty good job at isolating most stuff over 20Hz (will be down 10x at 20Hz). Another slab of granite is not going to make much of a difference in the isolation.
Thanks audiozenology. I'm going through the myriad of springs Fastenal carries. So I should pick one that approaches its max spring capacity? They do have some in stock that has a mx bearing of 57 lbs each. Should I get those?