Under speaker metal SPIKES ...what is the point ?

just wanna know if there is any ( i'm sure there is )
phisycal explanation for using metal spikes under speakers..
instead of using rubber or plain nothing ..

i would think it is to minimize contact level at maximum..
but what do you get by doing that ? :)

Following the above thorough reviews regarding the physics of spiking speakers, I'd like to add some more commentary regarding the sonic advantages. I hardly consider myself to be golden-eared, but the changes wrought by spiking my speakers were anything but subtle. The entire spectrum became much more natural sounding, with an especially focused image vs. a previously somewhat blurred image. Staging was also enhanced; wider & deeper. Bass articulation & control was also significantly improved. This much improvement for so little $ spent makes spiking one of the most cost effective tweaks that I've ever undertaken, & I ask myself why it took me so long to do this when it was so easy & inexpensive. But just like upgrade cables & AC cords, I didn't really want to believe it until I tried it. Presently I'm using plated brass cones, but now I'm curious about trying out some different spikes, footers, even pods, in order to determine which ones (or a hybrid mixture of them) will provide the best results.

Looks like that most people appreciate using the spikes !
I would like to try it myself !
However one question, how can add I spikes to my
original (not i-version) psb stratus gold, thanks !

p.s. BTW, is it a good idea to put a quarter under the spike
to protect the floor ?
As mentioned, spikes reduce the contact surface and form a more rigid coupling to the floor. A simple experiment can illustrate this--take a telephone book (the bigger the better). Slide it on a smooth surface. Then tape three pennies on the bottom and slide it on the pennies. Reducing the surface area increases the friction and makes it harder to move. As to the second part about disapating energy through spikes, the theory is correct, but I don't think in practical terms it is very effective. Disapating energy is best done with devices designed to do just that. I have a few of these made by Teknik (I think), but I don't think they work very well. The theory is they convert the vibrational energy into heat energy.

Why is coupling the speakers to the floor important? You increase the effective mass of the speaker. This is important for accurate bass reproduction (which intail effects the entire frequency spectrum). The bass driver in your speaker works like a piston moving back and forth. You may have heard "for every action there's an equal and opposite reaction" (I didn't make that up--Newton did). If the speaker can move about it will, and thus the force that bass driver is exerting is reduced by the movement of the speaker. If the speaker is coupled to the floor it can not move as easily, and thus the bass driver works more effectively. Not to belabor the point--there is still an equal and opposite reaction, but now the mass has increased as the speaker is coupled to the floor, so the movement is much smaller.

The effect of spikes will change depending (mostly) on a combination of speaker weight and the bass driver. Therefore a realtively large speaker with only 5 inch drivers will not benefit as much as either a mini monitor or a large speaker with a large (12 inch) driver.

In the end Argent said it right--try it,
I'd like to add a thought. Every comment above about using spikes to minimize vibrations and blurring of detail is 100% correct, and the minute I screwed spikes into the feet of my 200 pound speakers there was a substantial improvement. But then, on the advice of a dealer I trust, I set the spiked feet in Vistek Aurios Pro footers (round footers, about 3 inches across, with top and bottom plates which move independently of each other, probably on ball bearings), which decouple the speaker mass from the floor. The spikes rest in indentations on the top plate. If you tap the speaker, it will sway on the Aurios Pros. The effect in terms of clarity and detail is so astonishing I am in the process of buying Pros to go under every component in the system. (They do amazing things under turntables and transports also.) Skeptical? Try it, you'll be amazed.