should speakers be coupled or decoupled?

It's sounds odd but spikes both couple and decouple.

By coupling a speaker to a stand and the floor, there is mass damping of vibrations from the speaker. It has to do with Newton's First Law of Motion. When the speaker drivers move forward, there is an equal but opposite force pushing back on the speaker cabinet. Energy is wasted moving something other than the driver, i.e the speaker cabinet. But if the speaker is coupled to mass, it can't move. Just like you can't push your hand through a brick wall. So with mass coupling, energy is moving only the speaker driver. You want coupling to mass.

On the other hand, vibrations can move from the house into the speaker. So you want to decouple the speaker from those vibrations. That's where the spike is better than a an unspiked platform stand on the floor. The tiny point of the spike creates an impedence mismatch between speaker and floor.(That's mechanical impedence, not electrical impedence. They're different concepts.) In other words, it's hard for vibrations to pass through the small point into the speaker, so it decouples the speaker, although it doesn't help with airborne vibrations.

So you couple to mass, and decouple from external vibrations. A spike does both.

A ball bearing type of device will work like a spike as it has a small contact area. But it has to hold in place. If it can move or roll around, it won't work as well as a spike.

Rcrerar, my comments are based on the physics of what is happening. Sometimes what people hear is based on psychology rather than physics. although science can, and does, explain psychological perceptual differences too. One of the great difficulties in perceptual psychology, and audiophilia, is that is that we don't always know when differences are physical and generalizable to all, or perceptual on an individual basis...heard only by the individual. So science rolls on, we try to learn more about the variables and their effects/interactions. In the meantime debates rage and our arguments become almost philosophical until we learn more.

I am unfamiliar with the bearing systems you describe. There is a reasonable hypothesis that could be tested though. It is possible that the bearing surface is small enough to act like a spike and minimize external vibrations from entering. Yet, the mass or design of the speaker may be enough that the speaker movements don't affect the cone movement to an audible extent. So you don't need to couple to the extent that you would with a fixed spike. However, this hypothesis should only cause the system to equal a spike's performance, not improve it.

I remain open to any scientific explanation or theory as to how this works in terms of physics. Until then, I lean towards a psychological explanation as to any perceived differences. This is equally founded in science, but it is something that may not be heard by others other than as the result of the suggestion of marketers or those looking to sell or promote the product.

In other words, I prefer Newton's Laws of Motion as an expalation as to why spikes are better than a moveable bearing in a stand. If there are other explanations, I remain open minded. But the others have the onus of proof. Until then I prefer the psychological explanation. They may be hearing differences that are real to them, maybe because they want to hear a difference or maybe because it has been suggested that a difference exists so they perceive one. This is fine, but it applies to them and it is not necessarily what you or I would perceive.

Anyway, I'm reminded of a saying that I like: "Theory and practice are the same in theory but not in practice."

Stanwal's thought provoking post illustrates how observed "facts" can lead to philosophical arguments. When facts don't fit theory, or other facts, we use philosophy to reform arguments and assist in the development of new theory that better fits the facts. I put "facts" in quotes above because it is always an open question with the human variable as to whether the "facts" are, in fact, "facts" at all, other than to the person making the claim.

So, is it a "fact" that putting speakers on moveable bearings improves sound? If this fact can't be proven objectively or demonstrated to another person, then maybe it isn't a "fact" at all. Maybe it's just an opinion, and as such, only a fact to that person.

It is an observed "fact", and consistent with "theory", that the earth is round. So somebody looks out the window in Kansas and says: "My goodness, look at that, the earth is flat! That theory and those other observations about the earth being round must be incorrect. My friends here who are looking out of the window with me all agree. The earth is flat! We will have to change the theory that the earth is round to accommodate the observations that I and my friends have made about the earth actually being flat."

Anything wrong with this argument? No...Yes...???

Here's an analogy.

It is an observed "fact", and consistent with "theory", that putting speakers on spikes will improve performance. One of the theoretical bases for this is Newton's Laws of Motion. So somebody in Kansas puts their speakers on a moveable bearing and says: "My goodness, this sounds better! That theory and those other observations about fixed spikes must be incorrect. My friends here who are listening with me all agree! We will have to change the theory that the use of fixed spikes on speakers is based upon to accommodate the observations that I and my friends have made."

So, if you think moveable speaker stands improve performance, let's hear the theory upon which this is based so we can test it. If you don't have a theory, all you have is an opinion. And I prefer my opinion over yours. You see....I don't live in Kansas.