It depends upon your type of floor. Couple if your floor is rock solid and won't transfer significant amounts of vibration into your speaker. Decouple if your floor is relatively elastic and capable of transmitting vibration into your speaker. Think concrete slab construction ten miles away from any industry or highway versus a wood frame house with suspended flooring above an subway line. |
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. |
Markphd, I understand what you are saying and feel that your logic is sound, but recently I have read reports and reviews from credible and reliable sources that claim that the use of a decoupling device such as Symposium's Ropllerblock jrs., can and do outperform spikes, when placed under a loudspeaker. Now a device of this type, basically a ball bearing of some sort sandwiched between two discs with a concave surface, will allow a fairly large amount of movement of the speaker cabinets, even if they are fairly heavy. Do you have any theories as to why this result may have been reported? Are these people hearing things? I certainly hope that, one such as yourself, wouldn't go down that road as it would seem to be, well for a lack of a better term, a cop out way to explain what these industry professionals report to be hearing. |
On a lesser expensive level, I suspect one can ascertain for themselves what's best for their situation by trying both avenues... At least they'll find out what they can live with that way... and should.
you may enjoy using both methods simultaneously. Coupling say the stands, yet decoupling the speaker from them.
I'd go that way before I'd opt for some $200 + or way more expensive items that suit one path or the other best.... just to get some idea.
There's tons of threads here on this activity - philosophy, and it always comes down to what you will endure or enjoy the most. So, try both at some moderate level and go from there.
Remember, it's your ears and your wallet.
Happy listening! |
What about using Auralex pads? What is your opinion on these?
Joe in Mobile |
Frankly, I'm skeptical about putting speakers on roller blocks or any type of decoupling device that allows for any additional movement. I think that the last thing that you want to do is allow for any z-axis (forward/backward) movement of the speaker focal node. That's got to play hell with the speakers timimg and ability to image properly.
I live in Southern California, which means slab foundations. I have always had good luck with spikes, usually with some sort of footers beneath. For bookshelf speakers or monitors I have used both Aurelex foam pads and sorbothane mats. The sorbothane is much, much better IMHO.
Good luck |
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." |
It is not science to say that something does not exist until you have an explanation for it. Theory in physics is great but it is a broad extrapolation from reality, not reality itself. In any case there will be many effects that can affect the sound and theory by itself can not tell us which is the critical one. If we are not to depend on our hearing what are we to base our decisions on? Being convinced by a theory is no different than being convinced by some one else's glowing testimonials. Neither is definitive, science advances by discovering anomalous effects contrary to accepted theory. |
I completely stumbled upon this. I my second system which is in my gym I have rubber floors over slab. When I placed my speakers on the spikes, the spikes went thru the rubber mat and touch the cement pad below. I think the 3/4 inch rubber floor really dampens the spikes and stops any subtle movements.It turns out to be a really nice base for speakers. |
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. |
Markphd, I admire your immense patience. Of course spikes are the correct way to 'de-couple' speakers from the floor upon which they sit and I have answered many posts about placing squash balls beneath and timber platforms etc until I now just ignore the posts which continue to pop up every 2 months or so.
Your explanation of Newton's laws which explain why is again patiently put and your philosophical example of the earth being flat is a very good one.
I'm somewhat surprised at Stanwal who in the past has seemed to contribute intelligently to these discussions. Oh well, now I know. Thank you once again Markphd but, as you will quickly learn, the geese will continue to reinvent physics on every occasion in the belief that this is a 'subjective' hobby and not bound by the precepts of science. |
I can claim to have some knowledge of the working of science, I did my PhD research in it's history. I reiterate that what you are describing is not science. Quoting theory will not tell you in advance how something will sound, just how it MAY sound. If our ears are not the final arbiter of sound what is? In the old days there were stories of those who never actually listened to their systems, just watched them on oscilloscopes . Maybe the stories were true. As to cones, they COUPLE components, not DECOUPLE them. The makers of the ones I use, and sell, are very specific on this point and it should be obvious with a little thought. The purpose of the cone is to transfer vibrations as rapidly as possible [ ground, as they put it] to the floor. Decoupling the components involves PREVENTING the transfer of vibrations between the component and what it is resting on. How do you think a cone does this? See Star Sound site for their discussion. Decoupling is a totally different approach; Its leading exponent is probably Barry Diament, a prominent recording engineer, he has a web site. I have debated him on this point in the past. He also can produce elegant theory as to why his approach is better. As I really believe in science I am just at the point of ordering some FIM isolators which use the principals he espouses. I intend to see for myself which sounds better. I think I am right but I would like to know for sure. That, my friends, is science, all else is hand waving. |
The technical description of the Star Sound approach can be found here. http://www.starsoundtechnologies.com/coulomb.html |
Interesting responses. Thank you very much. Mark, I particularly appreciate the time you took to explain the physics/mechanics of this situation. |
