Vibrapods & Loudspeaker Serendipity
The Absolute Sound (118) june/july 1999
According to Webster, “serendipity” is “the apparent aptitude for making fortunate discoveries accidentally.” An example might be the clumsy cave man who was the first to drop a piece of Mastodon meat into the fire and thereby discovered – the barbecue! So it is that I wonder how many seemingly implausible tweaks may have been stumbled across by accident, or in the process of aiming at something completely different! Most tweaks focus on eliminating something unwanted, mainly resonance (or the effects of resonance on surrounding devices), by stabilizing something. Thus we have a myriad of suspension devices and sound-damping or deadening treatments. And most manufacturers today equip their speakers with stands or spikes and the means to attach them. Yet most audiophiles would agree that achieving optimal speaker setup seems to be a maddeningly elusive goal.Well, the good news is that something has come along to significantly affect loudspeaker performance, achieving a quantum-leap improvement through the elimination of micro-resonance that most of us don’t even realize is there until it goes away! And the whole thing happened quite by accident, using a product that itself was created by accident.
One day in a factory in St. Louis, Missouri, a CD player skipped. Now this factory, which happens to be owned by audiophile Sam Kennard, produces something called Flexible Vinyl Grommets – that is, collars used to attach tubes or pipes to sheet metal and provide a cushioning effect to absorb vibration and noise. It also happened that one of Kennard’s employees (also an audiophile) had often observed the leftover scrap vinyl and mused “Wouldn’t it be wonderful if we could use this stuff somewhere in audio?” And so, the Day the CD Skipped, Kennard got the idea to try a few of his flexible grommets under the CD player, and – voilà! – no more skipping (not to mention that they all agreed it sounded better, too, with “smoother treble, more open and spacious midrange and better-defined bass”). Kennard then tried them under his turntable with equally pleasing results and decided this was too good to keep to himself. So, after about a month of experimentation, testing, and modifying, he arrived at the design that is now the Vibrapod Isolator – a small (2-inch diameter!), saucer-shaped, flexible vinyl disc. Listening tests seemed conclusive, proving that the composition was indeed effective against “horizontally induced resonances” and would thereby improve the microdynamics of components of all kinds. The tests also led to the development of different densities – soft to hard – to accommodate light versus heavy components. Thus, the current lineup includes five “models,” which differ only in tensile strength, not physical size, to accommodate weights ranging from 2 to 28 pounds.
I was sent a full complement of Vibrapods to experiment with, and did so under virtually every component in my system, according to instructions (look at www.vibrapod.com for details). The weight and bulk of the turntable kept me from moving it around to compare it with versus without, so I can’t say anything definitive about that, but it did seem that the most audible results were obtained under the CD player. Perhaps this is because a CD player has an electromechanical function with moving parts (i.e., the transport) that are inherently more susceptible to self-generated vibrations. Nevertheless, there was no question that the sound was smoother and less strident with the ’Pods than without them. (For this component, I used the “sandwich” method whereby you lay out the ’Pods and place a piece of shelving or tempered glass over them, and then place the component atop that.)
Then I put it all aside, feeling that the CD player results were confirmation that the Vibrapods would make a positive improvement wherever used, and more or less left it at that – until I got my new Von Schweikert VR4 Generation II loudspeakers. I really didn’t want to use the supplied spikes and hoped that the low-pile carpeting would render them unnecessary. It seemed that low-end extension was deep, clean, and solid, and all who heard them (including a perfectionist amplifier designer) were impressed – which goes to show how accustomed we become to certain kinds of ever-present, low-level distortion. Thus it was in a self-satisfied frame of mind that I idly wondered what would happen if I used Vibrapods under the speakers. I put one under each corner, cued up Side 2 of a very familiar recording [Classic Records’ reissue of LSC 2450, Schumann’s Carnaval and Myerbeer’s Les Patineurs, with Covent Garden’s Royal Opera House Orchestra led by Hugo Rignold] and – nearly fell off my chair! The two major things I listen for occur right out of the gate in the opening dance sequence of Patineurs: First, there should be a lustrous, rounded, yet almost “spitty” tonality to the sound of the piccolo, and then a substantive solidity to the drum beating cadence to punctuate the rhythm of the skaters’ movements. All of this came across with a refreshing sense of spatial accuracy. In addition, it turned out to be a rather startling demonstration of a system’s ability to enhance musical microdynamic changes (too often called “pace” or “timing”), a concept I’d been somewhat skeptical about up to that point.
Short of a complete megabuck overhaul, I have never heard (or heard of), anything that got that kind of overwhelming, dramatic improvement! The soundstage opened up horizontally, adding to the already excellent sense of depth, and the walls of my narrow (11-foot wide), sparsely furnished room just disappeared. The noise floor seemed to have fallen completely away, heightening the sense of dynamic realism to such an extent that the hair stood up on the back of my neck.
Transients through these extremely fast speakers were so much more wonderfully precise – as I listened to record after record, I was hearing the bow go down on the string, piano keys “bottoming out,” the impact of percussion instruments (with requisite movement of air), and an uncannily lifelike “presence” in voices. Moreover, a definite treble edginess I had blamed on room reflections (among other things) was completely gone, replaced by an overall tonal smoothness and lifelike finesse. Now I was perceiving those tiny, percussive, realistic details that had been somehow smeared over or dissipated by speaker (and floor) resonance.
I was all but seeing the dust motes in the stage lights…
The improvement was so utterly astounding as to make me a bit incredulous, so I decided to ask Greg Weaver (writer for Positive Feedback and the E-zine, SoundStage), to try the Vibrapods because he had done an extensive, definitive review of these same Von Schweikert VR4/II speakers, and knew them intimately. Coincidentally, at that time Weaver was in the process of evaluating Vibrapods, and he too had been experimenting with them on the speakers – only between the midrange/tweeter units and the bass modules, not underneath. So he tried it and reported the same exciting level of improvement that I was hearing (which he subsequently reported at length in SoundStage). Happily, this ruled out possible room parameter, interconnect, speaker wire, amplifier, or front-end variables. While he felt the Vibrapods had made a definite improvement between the upper and lower units, that paled by comparison when they were used underneath the speakers.
Results with my older Vortex Screens (also Von Schweikert designs) were equally convincing. These are full-range speakers in a single cabinet measuring 28 inches w x 9 d by 65 h. With an oak base and cap, they weigh about 120 pounds each. I removed the large Tip Toes and exchanged them for one #5 Vibrapod under each corner. Also, the room is a much softer acoustic environment than the VR4 room, having deep plush carpeting, drapes, and overstuffed furniture. Yet, here I heard the same kind of improvement, and most noticeably in the lower octaves. Similar results were heard by a buddy Screen-owner on the West Coast who offered this (uncoached) evaluation:
[T]he first thing I noticed was…more of a sense of solidarity to the speaker; [as if] the bottom end [were] fuller and more focused…There seemed to be more of a sense of the midrange, with the top end being a bit more open and sweeter sounding [and] an improvement in the microdynamics; it was as if the noise floor had been lowered considerably, so more of the subtler tones were more readily discernible to my ears. Amazing how these [Vibrapods] can do so much for the spectral balance and soundstaging of a set of speakers.
But what of other speakers?
I took the Vibrapods on the road and tried them out on a friend’s new full-range system, designer Richard Davidson’s Sforzando JL-1s, that have discrete midrange/treble and bass modules arranged in what appears to be a sub-sat type of setup rather than coupled together as a tower like the VR4s. The mids/tweets are set in a multi-directional array atop slender transmission-line towers, which are positioned toward the center of the listening room. The large (and very heavy) bass “modules” each house two 12-inch ported woofers and are positioned along the rear wall of the listening room.
Both the designer and the manufacturer commenced the experiment with skepticism, but the Vibrapod treatment was immediately audible. Moreover, while bass extension of the JL-1 measures flat down to the nether regions around 10Hz, their owner had been complaining about a muddy dissipation in the low end that he attributed to the resilient hardwood floors in his Victorian home. Now we observed unmistakably improved transient response in the low bass, plus overall heightened impact and clarity. There was a definitely wider, deeper soundstage and imaging, particularly on large and spectacular orchestral works such as the Classic Records reissue of the suite from Bizet’s Carmen [LSC 2449]. Thanks to the large listening room dimensions, an almost life-sized orchestra spread out before us. (Similar results were obtained even with lesser recordings.)
Weaver reported equally convincing results in his field tests, as well.
So, folks, at $6 each, I think this product is the audio bargain of the decade. We’re talking an average investment of between $48 - $60 total for a sonic leap forward ordinarily not attained except with expensive upgrades – if then! And as if the manufacturer’s satisfaction or money-back guarantee weren’t enough, the Vibrapod Company also donates 10 percent of sales to outreach organizations. So it seems to me that you have nothing to lose. This decision is your basic no-brainer.