Vibrations induced from loudspeakers can turn the surfaces of a room into unwanted sound radiating sources. Vibrations can also induce noise in the output of sensitive electronics such as turntables due to the phenomenon of microphony. The patent pending design of our Carbide Base audio isolation feet isolates these vibrations in all directions across an exceptionally wide bandwidth when placed under your audio electronics and loudspeakers.
In addition to isolation, it is also important to reduce the magnitude of stray vibrations and dissipate them over time. Carbide Base footers utilize specially formulated viscoelastic materials with high loss factors to remove over 65% of incoming vibration energy through a conversion into heat. Undesired resonances are subdued.
Separate upper and lower portions are designed to optimize vibration isolation and dissipation in vertical and horizontal directions.
The upper portion is machined out of aluminum billet to accept a specially formulated viscoelastic member called ViscoRing™. The ViscoRing™ provides vertical vibration isolation and is replaceable depending on the intended supporting weight range. A standard 1/4″-20 top threaded hole can accept either the tip of a floor spike or threaded adapters for optionally mounting to your equipment or loudspeakers.
The lower portion comprises separate machined stainless steel sections. Exceptionally tough zirconia ball bearings and viscoelastic elements are incorporated to enhance horizontal isolation and damping. The bottom is threaded to facilitate height adjustment and can optionally accept 1/4″-20 threaded spikes to pierce through carpet.
When it comes to viscoelastic materials providing isolation, more is not necessarily better. It is the low ratio of surface area supporting weight to the surface area free to bulge outward which allows for a low resonance frequency and therefore a wide bandwidth isolation of vibrations. The term for this ratio is Shape Factor. The lower the Shape Factor, the greater the potential degree of isolation.
Carbide Base audio isolation feet are the culmination of 2 years of research and development to implement viscoelastic materials with a Shape Factor far lower than previous designs. The large tubular shape of the ViscoRing™ maximizes the surface area that is free to bulge. This yields a Shape Factor around half of the lower limit traditionally used for elastomer isolators. Such a low Shape Factor is made possible by the novel design of the upper portion of the Carbide Base footer. Ridges selectively brace the ViscoRing™ to stabilize it under compression while leaving a substantial surface area free to bulge.
"Carbide Bases not only turned my DAC into a gutsier and rounder version of itself, but also faster and dynamically more gifted on top of that. This sensibly more elastic, orderly and optically grander outcome was quite the surprise for me."
"Bass cleaned up even more, my small knots of structural striations vanished and floor-borne involvement felt eradicated. On a good day I'd expected that, just not this much. What came as a shock? The entire system's noise floor seemed to have fallen."
All Carbide Base footers are the same size. Each is optimized for the weight of your equipment by choosing among the 3 available interchangeable ViscoRings™. The recommended supporting weight range with each ViscoRing™ installed is shown below.
While some isolation devices require different versions for different weights, a single version of the Carbide Base footer can support a wide range of equipment weights by simply replacing the installed ViscoRing™.
Transmissibility is the ratio of vibration energy transmitted into one side of a Carbide Base footer (such as from a loudspeaker) to what is being applied to the other side (such as the floor). A transmissibility less than 1 is represents vibration isolation which is desired. Anything greater than 1 is an amplification of vibrations.
Most passive vibration isolators exhibit an amplification of vibrations at frequencies near the resonance frequency of the device. The unique design of the Carbide Base footer minimizes this amplification and confines it to frequencies around the lower threshold of human hearing. Low frequencies are important to isolate as they travel with little impedance throughout the room and equipment as structure-borne vibrations.
Loss factor, or tangent delta, is a measure how much vibration energy is dissipated through a conversion to heat due to the phenomenon of hysteresis. A loss factor of 0 indicates a perfectly elastic material where the oscillating force of a vibration occurs in-phase (at the same time) with the accompanying deformation of the material. A loss factor of 1 indicates a perfectly viscous material where the force and deformation are exactly 90 degrees out of phase resulting in total dissipation of vibration energy to heat.
The viscoelastic materials utilized in Carbide Base footers are engineered to have an exceptionally high loss factor over a wide frequency range. The gray ViscoRing™ has the highest loss factor, followed closely by the blue and black ViscoRings™ which can support higher weights. For reference, natural rubber has a loss factor of about 0.05.
The vibration dissipation ability of a Carbide Base footer is significant enough to measurably subdue resonances in equipment being supported. The graphs below show low frequency vibrations in the bottom and side panel of a test loudspeaker enclosure as measured using a calibrated accelerometer. Dips and spikes in panel acceleration indicating resonances are effectively damped when the same measurement is taken with Carbide Base footers placed under the loudspeaker.
Loudspeaker panel acceleration measured with a ACH-01 sensor, 10 dB gain, using 35 to 150 Hz log swept sine excitation. The measurements on Carbide Base footers are shown in blue. The measurements on floor spikes directly on the concrete floor are shown in red. See Measurements for details.