POSITIVE FEEDBACK ONLINE - ISSUE 29
as reviewed by Dave Clark
A while ago, I wrote briefly about the EquaRack Footers. As I recall I said something to the effect that they are really cool and yet so #%@% aggravatingly $#*&! to get them just right. A very slick idea that, once they are "right", are quite right sonically.
Some changes have been made and they are much easier to set up. One still has to do some math, but it is much easier to place the correct number of Viscoelastic pellets in the bottom piece and center the top piece so that it all sits straight and proper. Supplied is a collar that helps to align the top and bottom along with the fact that the tolerances of the counter-bored holes for the Viscoelastic pellets allows them a better fit.
What one needs to do is weigh the component under consideration, decide how the weight is distributed (front to rear, left to right), and use the appropriate number of pellets for the footer that will bear each respective load area. Use of three to four footers is suggested based on the overall weight of the component. Each pellet can take up to 3lbs and should last longer than the ozone layer under normal use. Supplied for the top half of the Footer is a Viscoelastic insert to eliminate the metal-to-metal contact between the component's bottom and the footer's top—and to a great degree damp the chassis. A nice touch as metal-to-metal contacts (like say… between a metal cone and the bottom of a component) will only exacerbate resonances in some way resulting in something that is usually not happening for musical enjoyment. Yes, there are no doubt instances where a little more zing may be the cat's pajamas, but in my experience the less metal-to-metal contact (among suspension devices) the better.
What is going on with the Footers from EquaRack? Well to quote their site (which is way easier than trying to put it all into my words, and since they already did a nice job, lets go that route)…
The Viscoelastic Couplers and Pellets provide superb damping of vibratory energy by hysteresis. The Pellets provide superb isolation by both deformation and hysteresis. Unlike most elastomeric "isolators" which behave like an undamped spring, the Pellets exhibit excellent "shock-rebound" (vertical isolation) properties similar to a high-performance viscous (fluid) shock absorber, in combination with a spring. In addition, unlike "hard" footers and those with thin, laminated or constrained viscoelastics, the Viscoelastic Pellets can deform laterally, and thereby act as elastomeric bearings—providing significant lateral isolation in addition to vertical isolation, for the benefit of the component.
The top discs of the Footers can deflect from the horizontal plane due to the elastomeric nature of the Viscoelastic Pellets and Couplers, and will thereby "self-align" with the chassis of a component which is uneven or not plane, thus ensuring proper contact.
"Isolation Platforms", regardless of cost and sophistication, which support components by their stock feet simply ignore the important issue of component chassis damping. Such products may provide isolation ONLY, but this alone is rarely sufficient to provide ultimate component performance. Stock rubber feet provide very poor chassis damping and actually "trap" degrading component-borne vibration.
Okay so the Footers can damp and isolate a component from room resonances. Along with that, they do not couple a component to a surface or other source of resonances as do pointed cones and such—they are best seen as decouplers. Again, from the EquaRack site…
Isolation & Damping Explained
At minimum, prospective buyers of vibration control products should know the basic definitions of, and the distinctions between ISOLATION and DAMPING to enable them to make informed choices.
ISOLATION refers to the process of preventing externally generated vibratory energy from reaching a component. Although this includes acoustic or air-borne vibration that is difficult to manage in exposed audio/video equipment, we are primarily concerned with the transfer of mechanical vibration. And, it is essential to understand that there is no significant mechanical isolation possible unless there is relative movement between the component and its supporting structure. Therefore, only a device or material that can compress like a spring or deform like an air-bag or a viscoelastic, or "roll" like a bearing, can be an isolator. The only exceptions to these "passive" examples are "active" systems that have electromechanical "self-leveling" capabilities. Obviously, hard "spikes" are not isolators!
DAMPING refers to the process of removing internally generated vibration that is inherent in a component AND any external vibration that for lack of adequate isolation, may enter the component, by converting the mechanical vibratory energy of solids into heat energyalready, a process called hysteresis. Damping is generally accomplished by the bonding of viscoelastic sheet materials to the (vibrating) internal surfaces, mechanisms and parts of a component.
Okay so what does that mean to the end user... I mean what and how do we address that here? I use a combination of Townshend Seismic 3D Sinks and various BDR cones and such to tune the system. That is, I see this as a system and not individual components. If one item is resonating or singing, then they all are to various degrees—one has to find the right harmony of sorts to get them to sing together, or better yet, to not sing at all, though I suppose in the end it is all a matter of tuning or finding that right harmony or seasoning. After all it is a matter of taste and preference, along with how much one is sensitive about these sort of things, No doubt some could not care less about this sort of thing, but damn, I ain't one em! So far I am quite happy with how things sit on this and that—it works musically for us ...it tastes good. The system sings in a decent enough harmony.
On the other hand the Townshends tend to loose air over time and as such require a periodic pump or two. When this happens, the resonant (or vibrational) issues' of the component change making whatever is sitting on the deflating culprit to change sonically—audibly. No, this is not an overnight issue, but one that occurs over a week or two, yet it does occur meaning that for any serious listening we need to check the pressure and get the sinks just right. When they are right, the results are clearly audible—more open, clearer and cleaner. Less smear and blur… you hear more music. But then the component will also lean to left or right (not politically mind you) as the weight distribution is never centered, requiring one to use weights or offsetting the position of the component on the Sink so it sits level. Not a deal killer, just something one has to deal with bladders.
With the Footers we hear less smear, more openness, cleaner more articulate bass, and well, they simply make the music more involving. We can relax more into the music as opposed to having to work in following the flow. It sounds better with! What's going on you ask? All I can surmise is that the vibrational nasties are being dealt with so that all one is hearing is the component and the signal—or music. Not the smear and additional crap, vibrations and resonances added to the signal. Cleaner, clearer… more delineated.
Do the Footers offer an audible advantage over the Townshends and or mixture of cones and such? Well not so much sonically as we had a hard time choosing one over the other in terms of being musically better—they both work well, though the Footers are a simpler approach to what we have here. That is, the Footers are easier to set up and do not change over time—what you hear today is what you will hear tomorrow or the next year… no need to adjust this or that and then worry that things are changing slowly as one spins ones' music. These are a real no brainer.
When used in a video HT set-up—like under the LINN Di DVD player—the results are quite impressive. Better visual focus, in that the images are cleaner and more detailed, colors are richer, blacks and shadows allow for more contrast and shading, yadda, yadda. The Footers allow the LINN do its stuff with less interference from vibrations and such as one experiences with a HT rig. Is this an issue of there being less work on the LINN's part to correct for errors due to misreads or what? Is the LINN able to extract more information from the discs—cleaner and faster? Questions, questions… no way for me to know. But bangs and booms from the sub just have to wreak havoc on a DVD player and the Footers address these issues with aplomb. They work as advertised.
It is interesting to listen to the changes when one removes the top viscoelastic insert and lets said component rest au naturel on the Footers. Music takes on a slightly pronounced presence or zing in the lower treble—a lot of what one hears with metal on metal. Even set as such, they work as advertised—still sound better than stock feet or other coupling cones—but the addition of the viscoelastic insert really takes them to another level. This metallic presence is removed, and the music has a greater sense of naturalness to it—fuller, richer, more harmonically nice. Better in everyway.
Additionally, the Footers do not move all that much in terms of left to right and front to back, so bumping into a component will not set it into constant motion or send it crashing to the floor. The Footers are quite stable …yes there is a wee bit of give and take due to the Viscoelastic couplers, but nothing to keep you awake at night. Nor will they scratch the surface of a shelf or component. No need for protective cups or discs to protect Aunt Tilda's fine coffee table from some pointy cone.
Let me reiterate from the previous article… the Footers appear to work as claimed by addressing vibrations and whatnot that can spoil a component's ability to let the music flow. I have no way of measuring any vibrational changes in a component—for the better or worse—when they are in use. They do though change the sound, that is, they do make an audible difference—and one that is clearly preferred or seen as BETTER!
Compared to the any of the components au naturel, the Footers will be a dramatic improvement in cleaning up—or opening up—the music. Simply better with, than with not. Compared to more traditional footers (cones and such), the Footers are better in offering isolation from vibrations as opposed to coupling or draining via a fixed point. I say better only in terms of my audible experiences; here with my components in my room. A lot of this tends to fall into the realm of taste and preferences (let alone what works with which component on what shelf), so items like these must be taken as a "got to hear it to see if I like it" sort of thing.
I can hear and see the differences—and the differences are for the better. Dramatically better when compared to something sitting on its stock feet. Naturally it all relates to the design of the component, as no doubt some items are made to address vibrations and resonances from the get go. That is the cabinet is machined from a chuck of unobtanium and is designed to address resonances with an iron fist. Other stuff is housed in some flimsy cabinet ripe for the being seated on something of obvious benefit. And even though the Cary 306 and SLP-05 products are quite robust, they both benefited from the Footers. The LINN unit features a less-is-more approach to its cabinet (simple folded sheet metal) and really benefited from what they could do. You've got to see what works for you.
I do recommend the Footers for those who are after getting the best from their system. They are obviously a well-thought out device to address resonances and are hassle-free. Highly recommended. Dave Clark