Here is my take on vibration as I was taught recently by a local designer here in New Jersey. He makes a vibration base that I just purchased after hearing and comparing it to many others. The base described below is designed for speakers but he also has a base for components which is the one that I purchased. Hope this is helpful.
Your speakers create a good deal of vibration, which is necessary, of course. Much of that travels to your ears by air and that is good. The rest travels via the floor and your equipment stands/furniture to your equipment, and that is bad: a feedback loop. There is also a great deal of noise of both natural and artificial origin that travels through the earth, your building, floor, equipment stands/furniture and also into the equipment, and that has unfortunate effects upon your equipment, too. The natural, geologically originated noise is ever-present low frequency vibration that travels easily through almost everything, and has components in both the vertical and horizontal planes. Artificially originated noise is also pretty much a constant in our environment nowadays. The noise from traffic, especially buses, trucks and trains can travel easily for miles through the ground. Soil types affect that, but all types carry noise. Within buildings motorized equipment such as washing machines, dryers, refrigerators, dehumidifiers, many others create noise that travels though the structure. All electronic equipment is affected negatively by vibration, which modulates what should ideally be a steady state of operation, only the sensitivity varies. Purity of musical reproduction suffers under this assault. Musical electronics need the best isolation possible from all this vibration if the result of their efforts is to be smooth, clean, and unaffected, and they need protection in all planes, not just vertically or just horizontally, and over the broadest range of frequencies.
Many devices and techniques exist for isolating equipment from vibration, but most are limited in some way, or are limited to effective function in only some limited way. Some are effective in only one plane (or even just one direction as in the case of roller blocks!), some in effective bandwidth, some fail in both ways. Even after an otherwise relatively effective system (an extreme rarity) has done its job, one final limitation affecting most systems, due the physics of resonance, gets its final licks in. No matter how good a material or combination of materials is in its compliance and ability to isolate, there is always going to be some level of a residual resonant passband for the entire system. Suspend all you want, however hi-tech fancy-sounding the material(s), no matter how compliant, no matter how good, there will be a remaining resonance frequency related to the suspended mass and its relation to what it is attached to or set on. Appropriately tuned *damping* is needed to "damp" out that remaining resonant frequency. It's basic physics. This means that some passband or frequency range of noise will get through, unless it is specifically targeted with a tuned means of damping and/or absorption designed to kill it. The IsoBaseK is designed to provide superior pneumatic (air suspension) isolation in all planes for starters using a butyl rubber bladder, and then targets that residual passband with silicone oil damping viscosity-matched to the load mass to finish the job that 5 other damping agencies start. This is for the same reason that cars have shock absorbers, which are called by the more appropriate description: "shock dampers" over most of the world. Many people think that "shock absorbers" suspend a car -i.e. hold it up off the road - which they certainly do not. The springs do that. Without springs, the car would fall to the ground and lay there on its bottom. "Shocks" control harmonic motion, keeping the car from continuing to bounce around after the initial bump is past, resulting in a "quiet ride". The same thing happens, albeit on the microscopic level, with vibration. Most existing "shock mount" systems are like a car with springs, but no shocks. They cushion the worst of the initial jar, but cannot do much to speak of about the continuing motion (noise) that follows until it decays naturally, nor any noise that falls within the passband of the resonant frequency, which passes right through. Because the most obvious bump is dealt with, most engineers and audio people figure the job is done. Riding in a car without shocks for a few days would teach them the reality of that lesson! The effect would be on a much grosser scale, but essentially the same thing. This knowledge is the basis of much of what K Works has done in the resonance and isolation design field.
The IsoBaseK
The basic premise is only the beginning, there is much more to the IsoBaseK system.
It is a carefully integrated system of synergistically cross-effective physical effect agencies. Even the simple looking plastic base has five discrete functions!
1. Holds everything together, the obvious one.
2. Controls the vertical to horizontal compliance ratio with its side walls to optimize them
(with some help from the sand in the middle). This provides superior horizontal
stability as a nice side benefit making the IsoBaseK much more user friendly than
items using roller block or ball bearing type (horizontal plane only) isolation.
3. Its flex is actually part of the suspension.
4. Allows cooling air to pass through from underneath when equipped with the optional
center vent for equipment with bottom chassis vents requiring cooling air.
5. In the event of a bladder rupture contains the silicone oil neatly in the sand.
The suspension, too, is more complex than meets the eye.
It starts with an air suspension using a Butyl rubber bladder, which has excellent internal damping in and of itself, much the same as the rubber surrounds now popular in speakers for this very reason, among others.
1. A Butyl rubber pneumatic suspension bladder is used. It is tough, conforms to
irregularities like equipment feet, and can withstand quite a bit of heat.
2. The base flex is part of the suspension.
These are then damped by no less than 6 interactive damping agencies:
1. Silicone oil matched to the load mass to damp the residual passband.
2. Butyl rubber air bladder has superior internal damping (lossiness).
3. Sand in the center.
4. Lead flakes within the sand.
5. Damping material in the foot blisters which contact the shelf below the IsoBaseK.
6. A damping polymer is used to attach the bladder to the base
Sand, simple as it may seem, is a wonderful acoustic material. It is very lossy internally and capable of sinking quite a bit of noise, especially when additionally loaded with lead flakes. The sand adds a mass (itself a positive thing in acoustic use) which provides a noise sink area within the IsoBaseK and, at the same time, supports the lead flakes which potentiate the noise sinking ability even as they add further mass. The sand also supports the inside perimeter of the air bladder compliantly and thus acts as part of the suspension at the same time that (micro) flexure of the air bladder by vibration imparts some of that energy into the sand, to die there. The lead flakes are spent bullets, no two any more alike than snowflakes. This means that their resonant signature is equally diffuse, spreading the Q, or bandwidth spread, of their effective damping spectrum, as opposed to using one or two gauges of something like lead shot. Shot would not stay in the middle of the sand, anyway it would always migrate down to the bottom, losing the effectiveness of the configuration. It is not capable, due to its round pellet shape, of acoustically coupling with the sand as well, besides. Obtaining and cleaning spent bullets is much more expensive than simply buying lead shot, but it is far more effective.
The IsoBaseK can be described as a pneumatically suspended, silicone damped, vertical-to-horizontal damping/compliance ratio controlled device with its own internal vibration sink, six discrete damping systems, and an integral base which itself has complex active functions.
The sum total of the complex interplay of design features and functions is the synergistic amplification of the desired effect of the most complete isolation possible for the most reasonable price possible. As the unit resides almost entirely out of sight under equipment once in use, the design focus has been on the physics of its function and economy of price rather than eyewash for sales promotion.
The Q of the IsoBaseKs is exceptionally low, what with 6 separate damping agencies at work, plus carefully chosen materials, and the remaining resonance is very small. But, the Iso masses only just a tick under 5 lbs., so anything sitting on it will be still larger, and influential. Therefore, the viscosity, which controls the main damping frequency center, is matched to the load/ IsoBaseK resonance system to tune the damping to the remaining "pass band", to damp that out specifically.
The IsoBaseKs not only effect superior isolation from beneath them, they are also capable of sinking and damping out some of the noise generated *within* the equipment, such as from transformers, motor drives, clock crystals, whatever. This requires direct contact with the bottom of the equipment, so it is preferable to place the equipment directly upon the IsoBaseK unless the shape or size of the bottom makes this impossible for some reason. No other product on the market can do this.
