It's the speaker stands ,dummy!
You have bought yourself a pair of your dream bookshelf speakers and then plod them onto a pair of stands of the appropriate height without any other due considerations, and find that the sound was less than what you expect. Despite running in after the required hours they still don't right. This can lead to another vicious cycle of changing the speakers, the amp, the CD player, etc. How many of us would take a second look at the stands? Probably not many.
The speaker stands is probably one of the most unappreciated item in a hifi setup. I would like to propose a probably outlandish idea to most audiophiles- that the speaker stand is more important than speaker it supports. This is an extreme thought but I feel that it is not that far from the truth.
Perhaps this truth would become clearer if some of the primary principles of speaker supports are discussed. The sole purpose of a speaker stand is to control the flow of vibrations away from the speaker . Holding the speaker at the optimum height is the commonly accepted mundane, purpose of the stand. Notice that the keyword is "control". In my own experience , I have found that attempting to suppress vibration by putting weights on top of the speaker, damping or clamping is a fruitless exercise. Vibration is like the other irrepressible force in nature - water. It seeks always to flow to the lowest point. Trying to stop vibration is like trying to stop a leak in a dam. Like water it will find another way to get through and often do it in a way we least expect and usually with dire consequences. I have found that suppressing vibrations in a speaker cabinet may apparently improve performance in such hifi parameters as tighter bass, better focusing , wider and deeper soundstage, etc. But without fail , I would notice that it has become less satisfying musically.
On the other hand , if the stand is ineffective in directing this flow of vibration away from the speaker it is supporting, the speaker can be overwhelm by the vibrations thrown up by the woofer. The speaker is left to cook in its own juice in a manner of speaking. This results in a boomy ,muddy, incoherent and smeared sound.
What makes a good speaker stands and why do they cost so much?
Maybe its better to look at the flipside. What makes a bad speaker stand? Maybe there isn't any. Again ,the picture of matching comes in. A speaker stand that sounds bad with a particular pair of speakers may work wonders with another pair of speakers. The reason for this is simple. It all has to do with how efficient the stands can drain away the vibrations created by the workings of the woofers. If your sound system is muddy-sounding, lacking in focus and booms- your speaker stands could be at fault. If the stands are solid ,of high quality and expensive, and your system still sound this way ,it could be due to misuse because of a poor understanding of how the stands work.
If your speaker stand is one of those cheap, lightweight affair and thus not too efficient at the transfer of energy, the speaker it is supporting tends to trap the vibrations in the speaker's cabinet creating that boomy and muddy sound. This is especially so if your speakers are of moderate quality where the cabinet construction are often lightweight. This problem affects not only the bass but also smear the highs as well. The tweeter produces frequencies whose wavelengths are in the regions of microns. If the entire tweeter itself is vibrating due to the woofer ,it will not be able to recreate those fine , delicate high frequencies properly. This situation is similar to the common experience of trying to read in a moving vehicle. The attempt will most likely give you a headache unless if you ride in a Rolls-Royce.
If your speaker stands are supposed to be the Rolls-Royce of stands and your system still sounds muddy , then maybe you are not using them properly. Maybe you have stuck blu-tack or some other soft compound under the speakers. Or instead of hard spikes on the base of the stands, you have replaced them with something that's not so unfriendly towards your expensive floor. Most likely something soft again. Using a soft, dead material between the speaker and the stands, or between the base of the stands and the floor results in decoupling. This impedes the efficient transfer of vibration energy from the speaker to earth , which provides an infinite mass to absorb such disturbances. Replace these with some hard cones such as ceramics, hardened steel, crystals or tungsten carbide bits. Cones commonly make from aluminum, brass or mild steel are not really hard but are still better then blu-tack or rubber feet for the job of maximal coupling.
In certain situations, a "bad" speaker stand may actually sound better than a high pedigree unit. I can see this happening in some hifi system where the equipment have a tendency to sound thin, bright and without much bass weight. If the stands are too efficient at draining away vibrations away from the speakers, they may exaggerate the problem. Thus it may be a good idea to use blu-tack, rubber feet, sorbothane or some other soft compound to decouple the speaker from the stand. Personally I do not see this as a long term solution to such a problem because the speakers will never get a chance to sound their best.
To sum up the discussion so far, a pair of speakers sounds best on stands that drain away just enough vibrations. Not removing enough results in the system sounding muddy and boomy. Remove too much and the sound becomes overly tight, lean and less musical. The audiophile's best bet is to buy the best pair of stands he can afford, that is one that is extremely efficient in removing vibrations, at the risk of making the speaker sounding lightweight. Then it is relatively easy to tune the efficiency of the stands down to a point where it matches the speakers. Whereas it is much harder to improve the efficiency of a poorly made stand.
Tip: How do you tell whether your present speaker stands are doing a proper job.
Play a piece of music with very strong bass. Place your hand very lightly on the speaker's side which has the most vibrations. Place the same hand on the middle of speaker stand's pillar. Compare the vibrations that you feel. You may have to do this several times to have an accurate assessment.
If the vibrations on the speaker is stronger then that on the stand. Your stand is not too good at its job.
If the vibration feels about the same, your stand is doing a decent job.
If the vibrations are stronger on the stands then on the speakers, you have one hell of a stand.
The next update will touch on how to recognize a well made pair of stands
Characteristics of a good , conventional speaker stands
The general perception is that a good speaker stand must be heavy and well damped so that it does not ring . Less well known is that the type and grade of metal used affects its performance. Which is why some stands cost a lot more than others. Other less obvious characteristic would be the effectiveness of the design in removing vibration from the speakers. For example the flatness of the top plate. All the stands I have used in the past fail this point. Place a speaker on a stand and it will be rocking away. Hook up the speaker cable and see your speaker do a twist to face away from your listening position. The only solution would be to place blu-tack or three cones under the speaker to stabilize it. A flat top plate ensures maximal coupling of the speaker. A good stand is thus able to efficiently remove vibrations from the speaker and sink this into the stand itself, which thus has to be heavy.