Having added my comments on the best found feet,I would like to mention the absolute best valued tweek I have found.At the cost of eight cents ,"that's Canadian " great improvements can be made to open the sound and give more life like timber to instruments.Try placing pennies piled two high under the four feet ,you could start with one under each to hear the changes,benefits seem to diminish with three .I also had succes with the pennies under my amp feet while expensive cones were piled in a drawer.
This can also be done to decouple between shelves ,for example placing the pennies between a corion shelf and my Townsand audio stand shelf.
This can also be done to decouple between shelves ,for example placing the pennies between a corion shelf and my Townsand audio stand shelf.