No one knows how and why, eh? Funny, I don't remember you asking me. Or have you've just not gotten to those whose names start with letter S yet?
Perhaps I should start off with a little background. I’m a huge proponent of proper AC mgmt and especially proper vibration mgmt both for which I call building on the right foundation. My position is that electrical and mechanical (vibrational) energies are a basic requirement for any playback system to function at all. Yet when under-controlled or poorly managed, these same two energies will utterly destroy our sensitive components’ precision and accuracy so that they can only perform at a small percentage of their true potential. Thus leaving a majority of the music information embedded in a given recording (regardless of format) so distorted that even though processed, it remains inaudible due to a much raised noise floor these very energies generate. A performance-limiting governor if you will. Our playback systems are like unto a vineyard where every participant has its role or responsibility within that part of the vineyard with little or no overlap into other parts of the vineyard. Except for electrical and mechanical energy which spans / overlaps and greatly impacts perhaps every last part of the vineyard and that’s why controlling these two energies whether using inferior or superior methods are the very foundation of every last playback system. And just as in perhaps every other industry, it is the foundation that ultimately determines the performance levels of everything built on top of it. Over the years, I’ve made some interesting discoveries (audio applications only) about these two energies, their behaviors, their similarities, and especially their tremendous affects on our playback systems.
That said, I’ll take a stab at answering your questions. Even though my answers will go against the grain of virtually everybody here because of their adherence to the vibration isolation methodology.
Q. Does a stand affect different frequencies differently?
A. No. At least not in theory. But perhaps in the form of some inferior designs and/or executions. Mechanical energy or resonance is essentially a universal and omni-present energy. It's everywhere and has multiple sources. And it's prominent in our listening environments, particularly in the form of air-borne and internally-generated vibrations e.g. power supplies, motors, and every last electrical part and wire within our sensitive components. And though there is mechanical energy in the flooring system too, it is essentially harmless. At least in comparison to the other sources. More importantly, in my experience this unwanted mechanical energy is a constant. If this were not true, then all one should need to do is listen to string quartet music at elevator listening volume levels and they should hear substantial improvements in their systems' levels of musicality. Try it and see. You shouldn't hear any improvements whatsoever. This simple test should easily confirm that neither air-borne nor especially floor-borne vibrations are the primary culprit. But when one considers that all electrical conduit and parts vibrate when current is passing through them, especially power supplies, it shouldn't take long to realize there's your constant / continuous source of mechanical energy that's bombarding our sensitive instruments and inducing the most serious sonic harm. So whether it's a transistor or op-amp vibrating from the current passing thru or because it's the most easily excited component within the chassis that acts as a release point for the isolationist who is intentionally but unknowingly trapping mechanical energy within, this should be enough to imply that in theory anyway, all frequencies are pretty much affected similarly across the entire spectrum. To the contrary, as I’ve said for years, since I do not stray from the basic laws and behaviors as I think I know them, in my own designs the gains are massive, they are many, they are across the entire frequency spectrum, and they are without a single negative. Just as I suppose one might expect the results should be when dealing with basic laws of nature and staying within those confines.
Q. Does it isolate the component making it immune from floor borne vibrations?
A. First I think it important to note vibrations have zero to with the 400 lbs. female guest at your party who’s dancing up a storm right in front of your TT that just caused your stylus to jump 13 grooves as that’s shock and impact and is another matter entirely. To answer your question, yes, if the designer was truly adhering to the isolation methodology in his designs (who really does?), but why would you care if floor-borne vibrations are of zero concern anyway? Especially since mechanical energy from other sources is already inducing constant sonic harm whereas floor-borne (and air-borne) vibrations should vary depending on volume, depth of frequency reproduction, and genre of music. Hence, if floor-borne vibrations were a problem it would induce an inconsistent sonic harm into our playback systems. Moreover, since we know mechanical vibrations in our listening rooms are generated from some say 1, others say 2 or 3 primary sources, once they are captured at the component chassis it matters not how they got there. Because once captured at the chassis, resonant energy now becomes a singular universal problem i.e. how to provide an expedited exit path before their energy is released within and absolutely cripple our sensitive instruments’ precision and accuracy.
Q. ... or does it couple the component to the floor and act as a conduit helping to drain energy away from the sensitive circuits?
A. No and yes. Well, sorta no and sorta yes. Since everybody here, including manufacturers, has committed their entire lives to the vibration isolation method, when they supposedly "isolate" vibrations which IMO is against the laws of physics, they are supposedly doing their very best to severe / de-couple any potential mechanical conduit from their components to the sub-flooring system. This is the major fault in the isolationists’ thinking that keeps their systems from ever sounding anything like live music. To think unwanted mechanical energy is coming up outta the floor toward our components rather than outta the components toward the floor. If we assume for the sake of argument that energy's primary behavior, when left to itself i.e. without our interference, is seeking to travel and secondarily, when met with resistance, seeks to release itself at the most easily excitable object within its path. So to answer this question, the less the designer understands basic mechanical energy behavior and principles, the more likely his product will allow at least some resonant energy (better than releasing no energy) to transfer away from the component before inducing its harm. IMO, this accididental release of energy is the only reason why "isolation" products can leak out some performance gains. For example. If a designer talks as though he's isolating vibrations away from our sensitive components, yet uses some certain hard rigid materials in his products, his words are inconsistent with his execution. But a poor mechanical conduit is always better than no mechanical conduit. This should not be difficult to understand since lightly tapping a tine of a tuning fork will present a definite vibration and ring for upwards of several minutes while the energy travels back and forth between the tines and since the energy has no exit path, releases its energy at the tines. Yet, tapping the top side of a box of sand simply makes little indentations in the top surface with perhaps zero vibrations and zero ring. Food for thought for the isolationist. Think of the tuning fork as your component and your hand holding the tuning fork and body as the isolating stand keeping the energy from traveling to the floor. There is only one true vibration methodology and that's resonant energy transfer and vibration isolation is simply a grossly inferior form of the one true methodology. IOW, if one hears improvements from their isolation-based products, it's because their products are inadvertently allowing some mechanical energy to drain away before it can induce its sonic harm. Why would anybody think severing a mechanical energy conduit requires a scientific background?
Q. Is it equally effective with tube and SS amps?
A. Aside from the tubes themselves potentially acting as easily excitable mechanical energy release points, not to mention any vibrations the tubes themselves may generate while current flowing is flowing thru them, a given solution should be otherwise equally effective. Assuming of course their construction build qualities and materials are otherwise similar too, aside from the tubes the results should be equally effective / ineffective.
Q. How do stands / racking systems affect our systems differently?
A. For better and worse, it’s the culmination of a combination of design and execution, materials, rigidity, fasteners, conduits used to connect the components to the stands, conduits used to connect the stands to the flooring system, quality of construction, weight / heft of rack and components, stress, component mounting, and type of flooring system. Just like an otherwise well-thought-out playback system, everything has potential influence. To more accurately answer your question I’d say: For perhaps all “isolation” products available today, actual results should be rather small differences as opposed to potentially humongous differences that could be had if anybody was open-minded to other methods of vibration management. In fact, to the best of my knowledge, the only way an “isolation” product whether active or inactive could possibly break free from this most serious performance limitation was if the designer was completely off-base in his attempts to isolate and perhaps all the planets were in proper alignment. I would think the fact that with the decades of isolation products of all sorts and the fact that they still remain in the tweaks / accessories category (rightfully so), only substantiates my claims here about performance differences being rather small.
Microstrip, "Guessing in the desert" is actually quite accurate. Including the more renowned "experts". Yet the moment these so-called experts present some measurement graphs as if to demonstrate due diligence, it seems many start salivating and looking for their checkbook. The inconsistencies of vibration “isolation" are everywhere regarding mfg'ers, their claims, their designs, and their chosen materials. Surely that should be obvious to some. And if that's not enough, most here who own some of the more highly-rated performance-oriented racking systems still call these products tweaks or accessories. Thereby, giving some indication they do very little in the overall scheme of things to improve performance and therefore, will always remain in the tweak / accessory category.
Just like a woman accessorizing her appearance with earrings can accentuate her beauty but earrings can never make an ugly woman beautiful. Not so with a truly superior / extreme vibration-controlling design employing the right materials and following the one true vibration controlling methodology – resonant energy transfer. Such a superior and extreme design when properly executed has the potential to transform an ugly pig into the most beautiful of all women. That's literally and without any hyperbole.