Does your subbase make improvements to the sound of the sub? Nice work btw 
Hi persisting1 and all Audio Circle members.
Did I miss your post or are you answering/commenting late?
I've tried the sub on the double spikes contraption (Patent pending

)
and the sub directly on the carpet with double underlay
and I could not tell any difference,
but that's me, does not mean there is no difference.
However, even if there is not difference, with my double spikes contraption
(Patent pending

) it sure look nice, look professional.
The idea of double spikes is a good idea, if it works one way,
it should work the other way around.
I am still trying to arrange my listening room which is combine with my office/stockroom and it's taking more time that anticipated.
Once everything is completed, I will try again my double spikes contraption (Patent pending

) and let you know my findings.
Guy 13
Thanks for asking