Carbide Base

Vibration Isolation + Dissipation

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 footer 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.

Multi-Axis Audio Isolation Feet

Separate upper and lower portions 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.

Low Shape Factor

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 footers 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.

ViscoRings™

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

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.

 

All 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 the amplitude of this amplification and confines it to frequencies around or below the 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

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 Bottom Panel
Loudspeaker Upper Side Panel

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.

Media

Dimensions

Instructions

Installing ViscoRings™

1 Insert supplied 2.5mm Allen wrench down into each of the 3 holes on the top pad and unscrew the bolts housed within. Note: Once fully unscrewed the bolts will remain retained under the pad.

2 Pry apart the upper and lower portions to access the installed ViscoRing™. Be patient prying apart as the ViscoRing™ can become tacky and slow to separate. The bottom portion can be partially unthreaded to increase prying leverage.

 

3 Replace the ViscoRing™. Ensure that the new ViscoRing™ is fully seated into the underside of the upper portion. Store the unused ViscoRing™ in a safe place. It is normal for newly installed ViscoRings™ to settle and compress slightly after an initial period of use.

4 Align the top holes on the upper portion with the thread holes on top of the lower portion. Press the upper portion down over the top of the lower portion.

 

5 Insert the Allen wrench into the top holes and tighten the bolts housed within. The bolt will stop turning when fully secured. Do not overtighten. Pressing down and lightly twisting the upper portion can help guide the bolts into their holes. If the bolts still do not align with their holes, remove the upper portion and try again.

6 (Optional) Unthread the bottom section as needed to increase the height of the Carbide Base< footer to level uneven loads.

FAQ

– What separates Carbide Base footers from the competition?

We believe there are 3 primary advantages of Carbide Base footers over the competition:

  1. Low resonance frequency in all directions – An exceptionally wide bandwidth of vibration isolation means that nearly all of the audible frequency range is isolated. This includes the lowest frequencies most likely to excite room surfaces. Many devices provide limited isolation bandwidth or are effective only in certain directions.
  2. High loss factor – Specially formulated viscoelastic materials convert over 65% of vibration energy into heat to effectively damp resonances. Damping is higher than many other devices utilizing vibration transmission-path evasion methods or inferior elastomer materials.
  3. Wide supporting weight range – Interchangeable ViscoRings™ allow a single device to effectively isolate a wide range of equipment weights. Some other competitors require purchasing different versions of their devices to support different equipment ranges.
Carbide Base footers didn’t work out for me. Can I return them?

Yes. We encourage new owners to give plenty of time to adjust to the differences introduced by our Carbide Base footers. If you are still not happy with the results simply return your item within 60 days to receive a refund. A return shipping label is included to simplify this for you. See our Return Policy for details.

– Should I use fewer Carbide Base footers with heavier ViscoRings™, or more with lighter ViscoRings™?

More Carbide Base footers with lighter ViscoRings™ will typically outperform fewer with heavier ViscoRings™ due to increased damping. However, low frequency isolation will be best when ViscoRings™ are used on the high end of their recommended weights. This might require using just 3 Carbide Base footers for lighter equipment.

– Do you ship internationally?

Yes. Click Add to Cart and specify your shipping address to get a real time shipping quote. Import duties and taxes are collected up front at the time of checkout to simplify customs clearance and to ensure that you are not responsible for any additional fees upon delivery. See our Shipping Policy for details.

– Can I use my own threaded adapters and floor spikes with Carbide Base footers?

Yes. Both the top hole and the bottom spike holes are the common 1/4″-20 threaded size. Many of the commercially available threaded adapters and floor spikes in this size should work.

– I heard anchoring is important in audio. Why do you claim allowing movement is good for isolation?

To provide isolation, out-of-phase movement must be allowed. If a manufacturer claims that their product “anchors” below a certain frequency or in certain directions it means that isolation is compromised in these situations. One manufacturer claims loudspeaker cabinet movement can be shown in the absence of anchoring by using laser vibrometry but this is deceptive. What is actually being shown is an isolation device with an increased peak vibration amplitude at resonance (a higher Q) due to lower damping, not physical “rocking”. While Carbide Base footers allow movement to achieve isolation, the high level of damping works to significantly subdue the magnitude and duration of these movements. Carbide Base footers settle quickly following the impulse of a vibration.

 

Below the transition frequency (typically around 200 Hz) the room becomes the dominant contributor to the listening experience in this region. Isolation of low frequencies is therefore critical. This is to minimize the storage into and subsequent delayed release of audible vibration energy from the surfaces of the room which can smear the bass and color the sound.