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Reviewer: Glen Wagenknecht
Financial Interests: click here
Sources: Audio Space CDP 8A CD Player
Luxman Brid CD Player modified by Audio Upgrades into a tube-less, zero oversampling machine with volume control
Preamplifier: Audio Space Reference 2S
Amplifier:Bel Canto 200.4
AV Receiver: Pioneer Elite SC-25
Main Speakers: Apogee Duetta Signature, Paradigm Servo 15 subwoofer
AudioSpace AS-3/5A
Stands: Charisma Audio Function stands,Target stands
AV Speakers: JohnBlue M3s
AV Subwoofer: Paradigm PW-2200
Desktop Audio Speakers: Swans M200 MkIII
Desktop DAC/Pre Headphone Amp: DA&T U-2
Cables: Audio Art SE cable loom, JPS Labs Ultraconductor 2 speaker cables, Signal Cable Silver Reference interconnects and speaker cables, digital optical and coax cable
Resonance Control: Solid Tech, EquaRack footers, Weizhi Precision Gold Glory footers, Boston Audio TuneBlock2 footers, Audio Exklusiv Silent Plugs, Superspikes, and Black Diamond
Powerline conditioning: Noise Destroyer power filtration
Accessories: TrueHarmonix Black Magic CD Mat, Herbie’s Super Black Hole CD mat
Main Room size: 12' x 17'
Home Theatre: 10.5’ x 16.5’
Review Component Retail: d. C. d. Feet CND$499/set of 4; d. C. d. Base CND$699

With the introduction of their unorthodox little Silent Plug, German manufacturer Audio Exklusiv found a new frontier to explore in the field of vibration management. It performed in such stellar fashion that it served as my enticement to examine their two companion resonance control products, the d. C. d. Feet and d. C. d. Base. Canadian distributor Charisma Audio and designer Andreas Schönberg were willing to satisfy my curiosity and patient enough to endure my barrage of questions.

The Silent Plugs have the distinct advantage of being unique and therefore top product in a field of one. The d. C. d. Base and especially d. C. d. Feet can’t claim such exclusive status. They face stiff competition in a crowded marketplace. As a point of comparison the feet would have to prove themselves against some innovative and effective designs in my stable of resonance control devices. Each of these have mildly different flavours. All are remarkably capable at their price. The Weizhi and Boston Audio are champions of the graphite approach. The EquaRack pushes viscoelastic design and the venerable Swedish pioneer Solid Tech has long advocated a slung suspension as foundation for non-resonant perfection. Against these the Audio Exklusiv would have to operate at top levels just to keep pace.

So what sets the Audio Exklusiv d. C. d. Base and Footers apart? d.C.d. here is shorthand for DeCoupling Damping. It’s designer Andreas Schönberg’s approach to resolving internally and externally generated resonances. Each of these products uses a sandwich construction with variations on a medically sourced fiber for isolation in the center layer. Based on application they diverge in material choices for the outer plies. The Base measures 500 x 450 x 40mm WxDxH, weighs 6.8kg and uses finished MDF construction with internal damping in the top section. It is designed to accommodate components up to 40kg. The Feet are polished aluminum cylinders with a 55m diameter and 25mm height. They support components up to 24kg when employed as a full set of 4. Unlike the EquaRack MF-1 footers to which this product otherwise bears a striking resemblance, the Audio Exklusiv does not use a top damping layer at the contact point with the component. It instead opts for bare metal to facilitate the transfer of vibrational energy. The top layer of the d.C.d. foot is internally damped using the same material as found in the Silent Plug. The bottom of the foot uses a thin layer of felt.

To get better insight into the approach and optimal applications for the d.C.d. products I contacted the manufacturer. Here are the questions and responses that came up over the course of the review.

Q. Are these legacy products originating with the earlier incarnation of the company or a fresh direction you started?

A. All accessories including the resonance-absorbing technology are a new direction from my side.

Q. For the d.C.d. base, why did you choose MDF over a more exotic material? Was it simply a case of a predictable resonant structure?

A. If you test any table, base or rack, you can hear and measure one or a few key resonances at a core frequency if you stimulate the item. For example there might be one steep resonance at 1kHz with a rise of 20dB. We did a lot of measurements and were astonished to find that even expensive racks were showing spikes of 10, 20 or even more decibels. The same holds true for feet and spikes. This explains why racks and feet produce different sonic signatures. We tested a lot of materials to understand the influence of each. Finally we found an MDF variant which was soft but not too soft (which would be bad) and exhibited but a weak resonance at a single frequency of 6-7dB. The varnish we use damps that down further. Then we use a layered construction. Beneath the top plate hides a pocket with a heavy foil to calm down the wood composite by another 2dB of attenuation. The bottom plate uses no extra ‘tricks’. It should be placed directly on the floor or rack to calm it down. Between both plates sits a special mesh we have adapted from medical technology. The construction of this mesh allows no transfer of any input frequency to render its isolation characteristics ideal.

Q. With regards to the d.C.d. feet, does the sandwich construction employ the same mesh and do you add internal damping in the top portion?

A. The construction is similar to the base. We use felt as decoupling material for the bottom. Between the aluminum layers we use a similar mesh for decoupling but its structure is a bit different because we must avoid the shearing force. In the top part we use internal pockets filled with the same material we use for the Silent Plugs.

Q. You indicated that ‘more feet are better’. Should I assume that using four instead of three is better?

A. Yes. It’s important to use as many feet as possible, not merely three. If you have a lightweight small component, put two underneath the unit and one on the top.

Q. Is there an ideal range of load per foot and where are they most effective?

A. No. Simply keep them within their maximum load rating.