FAQ's

Q: What are Herbie's isolation feet made of?

A: Herbie's compliant feet are molded from proprietary blends of platinum-cured silicones and inorganic fillers. The blended materials have a strategic balance of compatibility and incompatibility, resulting in strong viscoelastic compounds that never fully cure and achieve incredible vibration-absorbing and vibration-blocking ability. Having gone through incremental improvements over the years, Herbie's isolation feet are presently faster, more sonically neutral, and more articulate than ever.

Q: Do Tenderfeet "ooze" or leave any residue?

A: No. None of Herbie's products mar, stain, or leave a residue.

Q: How do Herbie's audio/video feet compare to "soft" footers like Sorbothane or Vibrapods?

A: Although they damp vibrations, most rubbery audio products respond too slowly to microphonic compression and decompression for superior audio resolution. Most are made of industrial rubbers like Vitron or Nitrile, or cheap plastics like PVC, all of which have resonance issues that muddy-up the audio spectrum. Soft polyurethanes like Sorbothane and Norsorex lack the reflexive counter-punch needed to fight microphonics and have a tendency to produce ill-defined bass and some high-frequency loss. Their use is virtually always at the cost of some sonic tradeoff. After all, the raw materials from which these products are made have been formulated primarily for purposes other than audio, e.g., footwear cushions, industrial seals, motor supports, microwave gaskets.

Herbie's isolation materials, on the other hand, are formulated only for audio applications. The compliant materials neutralize acute vibrations and resonance with firm counter-pressure, responding with lightning speed to micro-vibrational impulse. They will neither dull nor enhance frequency response. By simply reducing vibration, resonance, and microphonic influence, they help bring out the full sonic potential of your components.

Q: Are Herbie's isolation feet as effective as cones or roller bearings?

A: When cones or bearings are performing well, they inhibit vibrations from reinforcing and amplifying themselves. Instead of acting as vibration barriers or absorbers, they act as conduits to "drain" vibrations away. Components working well with rigid devices are basically in a state of vibrational equilibrium rather than being truly isolated and are dependent on the integrity of the shelf or platform they are used with. Particular "sonic signatures" are quite common. (The idea of draining vibration from a component into a rack which in turn supports other components is in itself a perplexity.)

Herbie's isolation feet, by contrast, decouple and isolate components and work well with just about any kind of shelf or platform. In most systems, components perform closer to their best potential with Herbie's isolation feet.

Q: How do Herbie's footers compare to high-end feet that cost $300 or more a set?

A: Because there are so many interdependent variables involved with any audio system, no single isolation device works best under every circumstance. Herbie's compliant feet, however, perform optimally over a broader range of parameters than most, synergizing well with just about any audio system. Herbie's isolation feet are not priced on how well they do compared to others, but are priced simply on what it costs to produce them. Don't let the low prices fool you; our products are simple, yet very effective high-end devices. In many blind and ongoing A/B comparisons with many different audio and video systems, Herbie's Tenderfeet (and Iso-Cups) have consistently equaled or outperformed highly engineered "marvels" costing many times more. With very small components, there is sometimes nothing at all that works better than a simple, inexpensive set of Baby Booties. Likewise with tube amps, economical Iso-Cups are rarely outperformed by any other kind of footer.

Deciding which isolation device is "best" is often just a matter of personal preference. For those of us who enjoy being absorbed in a real, up-front, musical presence -- neither artificially "smooth" nor dryly "analytical" -- Herbie's isolation feet are an ideal choice.

Q: Doesn't too much detail give you a dry, analytical sound?

A: An "analytical" sound is the result of some but not enough detail resolution. In such cases, subtle micro-detail and transients are lacking; major notes and dynamics are present but subharmonics and ambient indicators are weak. With sensitive and accurate detail resolution, you don't have to sacrifice "smoothness" to get detail, and vice versa.

Q: Does the audio component have to be a certain weight for maximum benefit?

A: Unlike soft feet that work best only within a narrow weight range, Herbie's footers give superior performance over a considerably wide weight range. Herbie's isolation feet will handle weight loads greater than the recommended limits; beyond a recommended range, however, a beefier footer with more vibration-absorbing capacity is sometimes preferable.

Q: How do I attach the feet to my component?

A: We recommend feet be used free-standing. Although they do not "attach" to components, Herbie's compliant feet make a firm, slip-free contact. When your component is placed on them, everything will stay put, almost as if the component were on suction cups.

If you wish to attach the isolation feet to the bottom of your component, however, some are available with pressure-sensitive adhesive, or you can adhere them with a dab of Permatex Blue RTV Silicone Gasket Maker (available at most auto parts stores for about $4).

(Iso-Cup footers do not "attach." The component sits on balls, which rest securely in concave, hemispherical "cups.")

Q: Would it be sufficient to use three footers instead of four under a component?

A: With compliant footers like Tenderfeet and Baby Booties, we usually recommend four for maximum benefit and stability. Usually, the more vibration-absorbing material in intimate contact with the component chassis, the more effectively the component's internal vibrations will be absorbed. (Depending on the component itself, however, three is often sufficient.)

With Herbie's Iso-Cups and frosted acrylic domes, we generally recommend three footers per component, although using four (or more) is not detrimental. (Some audio people recommend to always use three footers because "three points defines a plane." With cones and other rigid footers, this is appropriate advice--with compliant footers, however, that have some "squish" to them (including Iso-Cups) to compensate for a slightly uneven or unlevel surface, the "three points defines a plane" doctrine is basically moot.)

Q. Will my component have a tendency to "roll around" on Herbie's Iso-Cup footers?

A: No. Iso-Cup balls are held firmly in place and roll only minutely, imperceptibly.

Q: Is it okay to put Tenderfeet under the factory feet?

A: Herbie's footers always work best when in direct contact with the component chassis. This allows them to most effectively isolate the component and absorb chassis vibration.

Q: Does placing weight on top of a component help?

A: Placing a moderate amount of weight on a component usually helps isolation feet to perform most efficiently (choice of material is critical, though; inappropriate materials can introduce unwanted resonance). As opposed to rigid coupling devices that often require heavy weights for mass-loading, components sitting on compliant feet usually work best with just a small amount of weight (grungebuster Dots make an excellent decoupling interface between a weight and component chassis). Moderate damping inside the chassis is usually beneficial also, (regular hardware-store rope caulk is ideal for this).

We will gladly try to answer any questions you may have about Herbie's Isolation Feet