mitch2, The steel man argument for coupling is the speaker is vibrating and we want to hold it rigid to get the cleanest most dynamic signal for the greatest detail possible. So clamp it to the floor, especially if concrete, so it won’t move.
This works pretty good and in fact is what I did for years until learning it really doesn’t work that way after all. The speaker does vibrate, and no matter how massive or rigid so does the floor. It would have to, since otherwise if it didn’t move at all then all the energy from the speaker would reflect right back up the way all waves do. So the speaker is gonna vibrate no matter what. The question is how much and in what way.
Putting the speaker on springs allows the speaker to vibrate more freely and more independently from the floor. Nothing is ever truly isolated but this is a lot closer to isolated than coupled. As such a small amount of sonic energy is lost to the speaker moving more because its not supported so rigidly. But also it is moving a lot less because it is now decoupled from the floor. Even a concrete floor still vibrates, just at a different frequency and amplitude than wood. Speakers on springs excite the floor much less. Equally important, floor vibrations affect the speaker much less.
It hard to argue one over the other, but real easy to demonstrate in practice. The easiest way is to get the Nobsound springs off eBay for $35. These are adjustable for load to work under just about any speaker or component. Or you could buy some plain old springs for even less. Then try them and see.
When I did this it was pretty surprising just how much better springs are even compared to very good Cones. The proof of how they work is when used under subs. Putting them under subs not only improved the bass, it had equally as big an effect on midrange. How? Subs put out zero midrange. But subs energize the floor, the floor vibrates, vibrations reach the other components. The ear is much more sensitive to midrange details than bass. So putting springs under the subs cleaned up the midrange.
The difference is easy and obvious to hear. Try it and see.
