Speaker Spikes - Working Principle

@yoyoyaya "but they also stop the bottom of the cabinet from coupling directly to the floor". Yes, that crossed my mind as well. The spikes only couple the motion of the speaker assembly to the floor (undampened if made from just metal) and put on bare floor, or ’spiked’ (penetrating carpet) to wood underneath. .

But putting the speaker flat floor on the carpet rubber/foam underneath may actually help to reduce the vibrations of the cabinet bottom in the frequency range damped by the carpet/rubber/foam. Or looked at it the other way around: ’raising’ the bottom of the cabinet up from the floor may allow it to vibrate more freely and "change" the speaker sound.

Exactly right...

This is why i  was using with springs under and above my damped speakers by a load a sandwich of materials : plate of shungite or quartz feet , oak plate, sorbothane plate,bamboo plate, cork plate granite plate all together...

The alternating coupling and decoupling work the best to isolate the speakers , and the springs work best to decrease the speakers resonance ...

The granite plates (high mass) in conjuction with the carpet/rubber (bottom of carpet) and foam (under carpet) under the puck act as another ’swinger’ (mass, spring, damper) to further modify the fequency and amplitude transmitted into the floor.

@OP Carpet and underlay will not act a mass-spring-damper system. Locating the bottom of the cabinet in free space will not "change" the sound of the majority of speakers since they are designed to be set up in that way.

Ok , so set me straight. I have uber thick shag over extra heavy Gortex type padding. My house is a 35 year old cement slab build. I have a couple styles of speakers. Zu omens on spikes and JBL 4312A monitors on 3 leg Sound Anchor stands, both run spikes. Even with what a Sound Anchor stand weighs , I had to press them down to penetrate my floor covering and hit the cement. My floor covering is so thick and dense that without spikes the JBL & Sound Anchor combo rocks at the slightest touch. There’s no way I could run springs or pads. I purchased 4” think walnut slabs from Timber Nation and spiked them to use as footers under my Zu’s. They sounded like crap. I had conversation with the man himself in Utah and tried all his suggestions for spacing the Omens, nothing worked. The Omens on spikes leave maybe a 1/4” gap over the shag and have substantial bass, even with modest tube watts. I must admit I’ve yet to try stacking 2 completely different systems to make an Odd Couple ( pun intended ), but my spikes work pretty well. I think there’s some solid information in this thread, but it’s overloaded with theory based on reading articles Vs actual testing. I’m not saying people are wrong, but I’m saying some are being too absolute in their opinion. So I guess there’s more than one way to catch a fish. And please understand that my words are not meant to offend anyone, we have too much of that here. Happy Listening, Mike B. 

a good article on the topic