Glory I have had many different footers on many high end speaker systems. The magico q5's come with extremely well made and no doubt expensive spikes. If you think brass is the answer by all means enjoy. I have had spikes on tt's, on all types of stands, etc., don't like them. Don't believe in their "science". Here's an article that makes my point. Think as you wish, I prefer real science, engineering and independent thought.
Speaker Spikes and Cones Whats the point?
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by Jim Lesurf September 18, 2007
Diagram 1
In recent years it has become common for items of audio equipment to be mounted using spikes or cones. These come in all sorts of shapes, sizes, and materials, at all kinds of prices. The Hi-Fi magazines sometimes review these accessories, and recommend their use. However, are they worth buying and using? On this page Ill consider their use with loudspeakers, and discuss some alternatives.
Diagram 1 shows a typical arrangement. In this case there are a set of cones between the actual loudspeaker and its stand. (In some cases these cones are placed point upwards rather than as shown here.) The base of the stand also has spikes fitted i.e. long thin cones. These can penetrate the carpet, and if you have a wooden floor, they may then stick into the floorboards through the carpet.
In some cases, people use such spikes with some form of washer or coin so that the points sit on a small puck rather than dig into the floor. Also, sometimes the spikes do not penetrate the carpet or flooring. To start with, I'll ignore these possibilities, and return to them later on.
In general, Hi-Fi magazines claim that using cones and spikes like this will improve the sound. They also sometimes tend to describe the action of the cones or spikes as providing vibration isolation. Indeed, cones are sometimes also recommended for use under CD players, amplifiers, etc, and it is sometimes claimed that this can improve the sound by isolating the units from vibrations. This leads to two questions:
Do these cones or spikes actually do anything worthwhile?
If so, what do they do, and how do they work?
At first appearance, it seems plausible that cones under a loudspeaker should reduce the amount of sound energy transmitted between speaker and stand because they reduce the area of contact between the speaker and the stand. In the same way, we might expect spikes at the base of the stand to provide isolation. The basis of this idea seems to be that if the contact area was zero (i.e. no contact at all!) then no solid vibrations could pass. Hence if we make the contact area tiny, this approaches zero, so should only allow a small amount of vibration through. Unfortunately, although plausible, this idea may simply be incorrect.
We can understand how the above idea might be wrong by considering another example of the use of spikes a running shoe. Here the purpose is to increase the grip between two objects (shoe and ground) and hence transmit forces more efficiently. This example instantly shows that a cone or spike might not reduce the amount of actual force transmission, but actually help ensure effective transmission. Hence spikes and cones far from isolating might sometimes give a more effective link for vibrations to pass though.
In some recent issues of the audio magazine, Hi Fi News [ref 1], Keith Howard used an accelerometer to measure the levels of vibration in various objects. When he tried measuring the vibrations produced in a loudspeaker stand by playing the speaker he found a result that surprised him. With the speaker unit sitting on cones the level of vibration of the stand was over one hundred times greater than if the cones were replaced with small rubbery feet. This indicates that cones are of doubtful use if the intention is to stop vibrations passing from the speaker to the stand, or to any other solid objects against which the speaker may sit.
In fact, this result is also consistent with the predictions you can get by looking into the theory of vibrations in solid structures and objects. [ref 2] (Although such predictions sometimes need to be treated with care as the results depend upon the assumptions made when doing an analysis!) The theory and actual measurements seem to agree that hard cones and spikes are not necessarily a sensible choice if vibration isolation is what you require. An air gap or soft rubbery feet would probably be much better.
So do cones and spikes do anything useful, and are they worthwhile?
Spikes into the Floor
Despite the above, there may be cases where the use of cones or spikes do have an effect although probably not for the reasons often given in audio magazines. In some cases the effects may be unwanted, though, so beware. To illustrate this we can use two examples.
The first example is shown in diagram 2. This shows a side-view of a speaker on a stand without cones or spikes. The stand rests on the carpet. When we play music the speaker cones vibrate backwards and forwards. This produces the sound we want. However by Newtons Laws of motion it also shakes the speaker and the stand. The result, especially at low frequencies is a tendency for the speaker and stand to rock back and forth. Compared with solid materials like metal or wood, the carpet is quite soft and spongy. Thus it can act like a spring and allow the base of the stand (or the legs) to move, and the whole system wobble.
This behaviour may have various effects. One is that vibrational energy now finds it more difficult to escape from the speaker and stand into the floor. In this case, it is the carpet that is providing some vibration isolation. Another possible result is that, by allowing the speaker to recoil, we may be influencing how easily the speaker can produce low-frequency sounds. Hence we may find this alters the bass response. It may also be worth noting that when the floor does vibrate at low frequencies we may sense or hear these vibrations. Hence isolating the speaker from the floor might mean some other changes in the sound due to reducing the floor vibrations.
By having spikes on the base of the stand (as illustrated in diagram 1) we allow the speaker stand to grip the floor under the carpet. As a result, we can expect the spikes to reduce how much the speaker and stand wobble around, particularly at low frequencies. Unwanted vibrations or shaking of the speaker box and stand at low frequencies could then be reduced. By holding the speaker more firmly we may alter or assist its ability to radiate low frequencies. In addition, the floor may now act as a secondary radiator or medium to convey sound vibrations to the listener. Hence spikes under a stand may well have an effect we can sense, not because they isolate vibrations, but for precisely the opposite reason! To do so, however, they need to effectively penetrate through the carpet so the stand can grip the floor underneath.
What the above cant tell us, of course, is whether any changes produced by such spikes will be judged to make the resulting sound better or worse or even if the changes will be noticeable. That will be a matter of individual circumstances and the personal preferences of the listener. There are various reasons for this. One example is that, in some cases, the movement on the springy carpet might help damp out higher-frequency resonances in the stand more effectively than being gripped by the floor. Matter of circumstances which might be judged best for changing the performance in the way the individual user might prefer.
Cones Between Speaker and Stand
From the explanations given above it seems reasonable to expect spikes on a speaker stand to be capable of having an effect. So what about cones between a speaker and its supporting stand? For our second example, lets look at diagram 3.
Engineers are often asked to produce flat surfaces. Alas, flat is a nice theoretical ideal, but can sometimes be awkward to obtain in practice, especially when objects are being subjected to various forces which have the effect of bending or distorting their shapes. Diagram 3 illustrates this by considering what happens when the bottom of a loudspeaker unit isnt actually flat, but bulges downwards in the middle.
Ideally, if both the bottom of the speaker and the top of the stand are flat, they will make firm contact over a large area. The system would then be fairly stable, and would efficiently link forces and vibrations between the two. However if the bottom of the loudspeaker is curved then it might not remain stable on the stand. The curvature shown on the diagram is exaggerated for the sake of clarity, but should indicate what would then happen. With a curved base, any sideways forces would cause the speaker to wobble back and forth on top of the stand. However if we place some cones in between the speaker they act as legs to support the speaker in a few locations. This means we can now remove the effect of the underside of the speaker not being flat, and the result may be stable again. Hence cones may improve the stability of the speaker-stand combination by removing any problems due to the surfaces not being flat.
As with the spikes on the base of the stand the cones would, in principle, act here by giving a firmer and better-defined mechanical link, so do not isolate the speaker when behaving as described. In practice, however they may not always be required when used with decent loudspeakers and stands. The reason for this is that although not perfectly flat the surfaces of the speaker and stand may be flat enough that when they press together their elasticity allows them to deform and come into contact over most of the surfaces. Hence in practice, the surfaces may often be flat enough for any imperfections not to matter.
In principle, when vibrating hard objects are resting upon each other, the surfaces may vibrate enough to keep bouncing in and out of contact. The result then might be some unwanted distortion due to the non-linearity of the contact forces. (i.e. the surfaces might rattle together.) If this occurs, then compliant feet of some kind (or a layer of soft material in between the two objects) may be desirable to help ensure a more enduring contact. However having said this Ive have not encountered any measurements or observations which show this is a real problem in most practical cases with domestic audio speakers. I therefore have no reason at present to think that this problem does occur in practice, so no solution may be required.
Not Making Holes in the Carpet!
An obvious problem with using spikes as considered above is that we end up with holes in the carpet and floorboards! The good news is that with narrow spikes, the holes in carpet tend to close up and become invisible when the stand is moved. However, wooden floors are less forgiving, and there is an obvious risk of damage that might sometimes be unacceptable. Hence we may allow the spikes to press onto the carpet but avoid pushing them hard enough so they drive through onto or into the floor. When the weight of the speaker and stand is high people can choose to place the spikes on coins, or washers that act as a supporting puck and prevent damage to carpet or floor.
By placing the spike on a small puck we make it impossible for the spike to contact the carpet or floor. This means we can't expect the combination to dig in as effectively as the spike would do by itself. The combined spike and puck then will tend to act as a narrow hard foot. For much the same theoretical reasons [ref 2] as before, the result is unlikely to effectively isolate or damp any vibrations, although the stand may be held less firmly than if the spikes can grip the floor. Having said the above, using narrow feet might be useful in some cases. The weight and vibrational forces of the speaker will then be pressed onto a much smaller area of carpet (assuming the pucks are above the carpet) than if no feet or spikes are used. This may alter the effective stiffness of the carpet, and alter the ease with which the speaker may wobble, or lose vibrational energy. The resulting changes may be less when using a puck than when the spike is allowed to dig in, but may be useful in some cases.
When sitting on a concrete or stone floor it is unclear if a puck should be expected to do much in terms of vibrations. It may just prevent the spikes from blunting themselves digging small holes in the floor. However, either way, this arrangement will lack the grip we might get with spikes driven into a wooden floor. In general, therefore, we should perhaps view pucks or washers with caution as their benefits may be cosmetic rather than acoustic. Indeed, they may tend to defeat the purpose of fitting spikes at all. As usual, though, the results may depend upon the detailed circumstances!
The effect of using spikes which do not penetrate the carpet even without a puck can, again, be expected to be much like using narrow feet. It seems doubtful that they will isolate the stand from the floor. The results will depend upon how well (if at all) the spikes can grip the carpet without making holes. They may, however, act like the cones under a speaker and provide a more stable seating when the surfaces are not flat.
Softly softly...
For what it is worth, my own experience is that spiking the loudspeaker/stand through the carpet to grip a wooden floor seems to have a noticeable effect when I have tried it, and I think I prefer it in the main audio system I use. However there is no guarantee this impression would be the same in every case, or that you would agree with my preference, or indeed that I am not imagining the change it made! I can't say that I have ever had the feeling that spikes which do not drive through the carpet had any audible effect. Where genuine vibration isolation or vibration absorption are required my experience (plus the analysis and measurements I have mentioned) make me doubt that cones/spikes of hard material are a good bet. My own experience is that something like soft rubber feet (bumper buttons), or felt feet are more effective for isolation purposes.
Some people have experimented with cutting squash-balls in half, then using the resulting hemispheres of soft rubbery material as feet under loudspeakers or other units. I dont know of any measurements upon the effects of their use, however it seems quite possible that this arrangement would be better at isolating vibrations that hard cones or spikes. An alternative that was once popular was using a layer or blobs of Blu-tack. This is quite soft and squidgy when you apply a steady pressure. However it is more elastic and springy when vibrated. A potential problem with Blu-tack is that it contains a solvent which may discolour or mark other materials if held in contact with them for a long time. The material may also creep or dry out, and its behaviour change with time. Hence it may not be suitable for long term use.
Another alternative I have not seen suggested or recommended anywhere is the use of cut-up pieces of carpet tile. This tends to be a composite of a layer of a soft rubbery material with a fibrous layer. An advantage of these tiles is that they are cheap to buy, and easy to cut up into shapes. You can also stack them into piles of a few layers if you wish. Hence they are very convenient to experiment with if you wish explore any effects they may have. Another advantage is that they are available in a variety of thicknesses, colours, and patterns.
I dont know of any reliable measurements of the possible effects of Blu-tack or bits of carpet tiles used as feet. Hence if you try them you may decide that do nothing much, or you may find you dislike them. However if you are interested in damping or isolating, they seem worth considering as an alternative to the now-conventional hard spikes and cones.
The real difficulty with trying to deal with vibration and acoustics to improve a domestic audio system is that the circumstances vary a great deal from one system and room to another, and the preferences of the user also varies. My own experience is that the choice of loudspeakers, their location, and the listening position generally have a larger effect upon the sound quality than the use of spikes, etc. In some cases cones or spikes may be desired to give a better grip. In other cases some damping or isolation may be desired, so soft inelastic materials may be preferred. Hence when it comes to loudspeakers and stands, any specific recommendation may be fine in some cases, and poor in others. The best bet is therefore simply to experiment. I hope the above gives some food for thought if you are interested in doing so!
[1] Articles on vibration by Keith Howard in the July and August 2002 issues of Hi Fi News
[2] Textbook: Structure-borne sound, by Cremer, Heckl, and Ungar, published by Springer-Verlag.
Many thanks to Jim Lesurf for contributing this article. For more articles like this, visit: http://www.audiomisc.co.uk/index.html
Confused about what AV Gear to buy or how to set it up? Join our Exclusive Audioholics E-Book Membership Program!
See also:
How to Evaluate Loudspeakers for Sound and Accuracy
Vertical vs Horizontal Center Speaker Designs
By Jim Lesurf September 18, 2007
Recent Forum Posts:
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cpp posts on May 07, 2012 08:36
Tried it with spikes on, spikes off. Couldn't hear any difference AT ALL.
sasami posts on May 06, 2012 20:43
Isolation feet is very confusing. Isolation means remove connection between 2 object.
However most isolation feet works 2 ways coupling and decoupling 2 objects.
Means it either reduce the connection of 2 objects (rubber feet).
Or it harden connection between 2 objects (cone/cup, ball/cup feet).
These 2 method works on 2 compelte different theory.
By decoupling it allows free movement of 2 object i.e. reduce motion from 1 object transfer to the other.
When most think of antivibration they think this way so vibration from surrounding don't pass onto the gear.
Howeve by Newton's second law F=ma while Force (vibration) is the same the larger the mass less the accleration or motion.
So by coupling your gear to your rack then to your house using cones.
Means the same force that vibrate you gear now needs to vibrate your house, so it just end up moving nothing.
So rubber feet stop vibration pass to your gear when harden cones stop gear movingby increase total mass.
Since in most case the vibrating end is your gear rather then your house.
Unless you have a vibrating floor let hope you don't, a harded feet is better for stopping vibration.
As for the sound that really depends on personal opinion.
digicidal posts on December 22, 2010 14:28
I've always used a pair of stands I have with spikes as I always had carpet... but I've also always had cats and allergies and something had to change. (The obvious solution was not acceptable - since I didn't want to be single again and my wife really loves having cats).
So I tore up all of my carpet and laid down wood in the bedrooms and tile in the front rooms. First I tried using the little brass pucks that had come with the stands and was very disappointed in their performance - not only because it didn't seem to do much of anything except make moving them around during the placement phase a huge PITA but because I could actually hear the spikes vibrating in the dimple in the brass pucks. My first solution was to simply fill the dimples with silicone - which helped a great deal, but still seemed less than satisfactory since it seemed to make the speaker stand itself less stable.
Final solution - ordered some FLOR tiles... which were like a dream come true... the knap of the carpet was very dense, and they were backed by a rubber backing which was smooth (as opposed to grippy). This allowed me a couple of nice advantages... the first was the spikes would now bite into the carpet and the stands were stable, the rubber backing helped dissipate the vibrations instead of them just bouncing off the tile and back into the stand, and finally... I could drag the carpet + stand around on the tile fairly easily (although still requiring enough effort to be assured that the speakers would not move once placed).
With that done I could find the right placement for the speakers, then marked on the tile with tape where the corners should be - and now I can move the speakers out of the way if we have a party or something where I need to maximize floorspace and have them back into position within minutes when the guests leave.
Although I never had any proof... I always questioned the reasoning behind spiking component racks... simply based on the observation that if they actually served the 'audiophile purposes' of hard-coupling the speakers to the floor plane... then that same logic would dictate that the last thing I would ever want on my component rack was the same thing - since I'd then only be assisting any vibrations in the floor climb up the rack and into my components... When I bought my rack it came spiked... first thing I did was take the spiked feet off and put rubber stoppers on them (the kind you buy at HD/Lowes for leveling refridgerators/ovens/washing machines).
3db posts on December 21, 2010 20:43
Gustavo;775708
And what about that 5th foot under those Yamaha Aventage Receivers? What is it supposed to do?
Its clearly a "male" receiver.
Gustavo posts on December 21, 2010 18:08
And what about that 5th foot under those Yamaha Aventage Receivers? What is it supposed to do?
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