Carbide Base Audio Isolation Feet

Carbide Base Audio Isolation Feet

Vibrations induced from loudspeakers can turn the surfaces of a room into unwanted delayed sound radiating sources. Vibrations can also induce noise in the output of sensitive electronics such as turntables.

 

The patent pending design of our Carbide Base audio isolation feet control and isolate these vibrations in all six degrees of freedom when placed under your audio electronics and loudspeakers.

Multi-Axis Audio Isolation Feet

Separate upper and lower portions are designed to optimize vibration isolation and dissipation in vertical and horizontal directions.

 

The upper portion utilizes an aluminum housing machined to accept a specially formulated viscoelastic member called ViscoRing™. The ViscoRing™ acts as a damped spring supporting the equipment while isolating it from vertically oriented vibrations. It is replaceable depending on the intended supporting weight range.

 

The lower portion incorporates zirconia ball bearings and viscoelastic elements to enhance horizontal isolation and damping. The large bearings roll on raceways formed from polished hardened steel to minimize rolling resistance. The bottom can be unscrewed to facilitate nearly 3/4″ (20 mm) of height adjustment. It can also accept optional spikes to pierce through carpet.

Progressive 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 is important for improving isolation performance. 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 implement viscoelastic materials with Shape Factors 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 elastomeric isolators. The low shape factor is made possible by the patent pending design of the Carbide Base footer. Ridges within the upper portion progressively brace the ViscoRing™ as it compresses to stabilize it while leaving a substantial surface area free to bulge.

Sapphire and Diamond Inserts

The optional Sapphire and Diamond Inserts are additional vibration isolators which replaces the solid stainless steel top center section of the Carbide Base footer. The extreme hardness of the bearing raceways utilized in these inserts allow for additional filtering of low-level noise via the concept of vibration Transmission Path Evasion.

 

TwinDamp™

The Diamond Insert utilizes our TwinDamp™ material in 4 critical locations internally. TwinDamp™ is based on a manganese-copper twin crystal metal alloy which we refine with multiple stages of temperature treatments to further improve performance. This exotic material has over 10 times the damping capacity of copper.

Universal Stud System

Carbide Base footers can be optionally mounted to equipment and loudspeakers using commonly available flat head machine screws. Metric thread sizes from M4 to M10 and imperial sizes from #8-32 to 1/2″-13 can be used. A stainless steel jam bolt is provided to thread in behind the screw to secure it in place. A bolt kit including screws for 8 footers is available.

 

The top of the jam bolt has a threaded hole to optionally accept a spike to point upwards for maximum coupling to the supported equipment. The hole can also accept the tip of a spike when used under loudspeakers.

ViscoRings™

All Carbide Base footers are the same size. Each is optimized for the weight of your equipment by choosing among the 5 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

Conventional floor spikes under loudspeakers transmit a significant amount of vibration energy into the floor throughout the bass and midrange frequencies. Many traditional vibration isolation devices will provide isolation at higher frequencies but exhibit an amplification of vibrations in the lower frequencies near the resonance frequency of the device.

 

The Carbide Base footer excels in its ability to effectively both isolate and damp the lowest audible frequencies. Low frequencies are important to isolate as they travel with little impedance throughout the room structure and equipment, degrading audio fidelity along the way. The reduction of these structure-borne vibrations improves midrange clarity and bass extension by reducing the masking effect brought on by room structure noise. This reduction in noise transmission provides equally important improvements in the high frequencies.

Spikes
Carbide Base Footer

Horizontal vibration energy transmitted from a 2-way loudspeaker into a 3.6 kg (8 lbs.) weight placed on top of the loudspeaker. Measurements were taken with the weight on 3 floor spikes and then with the weight on a Carbide Base footer with a Super Light ViscoRing™ installed. Horizontal acceleration was measured with a ACH-01 sensor, 10 dB gain, using 30 Hz to 8 kHz log swept sine excitation.

Loss Factor

Loss factor, or tangent delta, is a measure of 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 green ViscoRing™ has the highest loss factor, followed closely by the other ViscoRings™ which can support incrementally higher weights.

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 panels 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 Vibration
Loudspeaker Upper Side Panel Vibration

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 the Vibration Dissipation Measurements for details.

Dimensions

Instructions

Changing ViscoRings™

Instructions for the removal and installation a ViscoRing™ inside the Carbide Base footer.

Installing Bolts for Speakers

Instructions for installing bolts onto the Carbide Base footer. This allows the Carbide Base footer to screw into speakers and equipment in place of spikes or stock footers.

Upgrading Carbide Base Insert

Instructions for upgrading a standard Carbide Base audio footer to Carbide Base Sapphire or Carbide Base Diamond.

FAQ

What separates Carbide Base footers from the competition?

  • 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.
  • High loss factor – Specially formulated viscoelastic materials convert up to 78% of vibration energy into heat to effectively subdue resonances. Vibration dissipation is higher than many other devices utilizing inferior elastomer materials.
  • 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.

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

In most cases only 3 Carbide Base footers are needed to achieve excellent performance. More Carbide Base footers with lighter ViscoRings™ will typically outperform fewer with heavier ViscoRings™ due to increased damping capacity however. Low frequency isolation will be best when the ViscoRings™ are used within their recommended weights.

Do you ship internationally?

See our list of Distributors to purchase from one of our partners locally. For all other locations we ship direct. Click Add to Cart from the product page 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.

Why is there a price difference between the standard and diamond version of the Carbide Base footer?

The PVD diamond coated ceramic bearing raceways and the TwinDamp™ parts are the largest contributors to the higher cost. Collectively these parts cost more than all of the other parts combined.

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. 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 midrange, limit bass extension, and generally color the sound.