by Karl Lozier
The effects of vibration on audio equipment and the sound quality then reproduced by our loudspeaker systems ranges from subliminal to downright annoying. Most vinyl or LP users are acutely aware of the concepts and the problems. LP users are well aware of the fact that the unseen (by the unaided eye) vibrations of that tiny diamond stylus is the source or should be the only source of what is heard from the loudspeakers. Sooner or later nearly all vinyl users become aware of the effects of the musical sound waves emanating from the loudspeakers. These airborne vibrations can and do affect every component in a music lover's system. It is true that often the major effect is on the analog's turntable setup and that is why I mentioned that users of LP recordings have or should have become so aware of the effects of air borne vibrations. Of course if you were not aware of the great importance you simply never came close to hearing how good your vinyl recordings could or can sound. Hundreds of pages have been written and published regarding prevention or amelioration of the problem with turntables. Before leaving this introduction to the problem of airborne vibration upon components other than turntables, I feel compelled to mention two other things of possible interest to the situation with turntables.
First is what many, not just myself, consider the ultimate cure for airborne vibration problems with record playing systems and other components is simple in the extreme! Not applicable in many systems for a multitude of reasons, the cure is to isolate the turntable and/or other components from the sound pressure waves. Yes, place the component in another room, preferably an adjacent one if practical - music lovers are often practical and audiophiles are questionable at best. Another yes is that means drilling appropriate holes through the wall through which the necessary cables are inserted. Lastly for this prologue to vibration isolation devices was something done many years ago by either the British magazine Hi-Fi News or the specialty series Hi-Fi Choice. Follow the disarmingly simple procedural setup and the clear implications carefully. As a quantitative/qualitative test, loudly play a LP recording and while doing so, swing the tone arm of a second record player (hooked up to another system if desired) around so that the stylus rests on top of the headshell (or arm tube) of the first, the playing turntable setup. Then measure the output of the second cartridge/turntable. Think carefully and ask yourself exactly what is being measured, as the stylus of that second turntable setup is not playing a groove in a vinyl record. How long in the vibrational, airborne or otherwise, chain is it creating an output in the second cartridge. In other words, vibrations can easily be a second sound source modifying the original or desired source being played.
Now on to devices meant to be used to eliminate or reduce vibrational effects on audio components. The setup I used to demonstrate and evaluate the effects was very simple and should be easy to replicate. Of course every setup may respond differently but the results are probably applicable to many if not most setups. A plus in this setup used was the fact that my walls are the old fashion kind, real plaster and lots of it over 4" studs; no flexing dry wall economy stuff here. The floor was economy stuff, a few inches of thick poured concrete. The carpet snuggled on top of it is a different kettle of fish, a more expensive one. In any event the general environment in the sound source area is probably as inert as it comes for any, sane audiophile. Some people consider the phrase "sane audiophile" to be an oxymoron but it really does not matter. Picture a pair of Genesis loudspeakers out just a few feet from the wall behind them. They are bipole radiators with virtually unexcelled bass response to a bit below an honest twenty-Hertz. They are approximately seven feet apart. Between them is a six-foot long cabinet with doors that are one of a like group that still serves as an LP storage or record cabinet. Internally there is a removable wood shelf upon which a tubed CD player resides, the latest Heart special model. On top of the wood cabinet rests the superb Cary model 306/200 upsampling CD player (not used for this review and true also for the next component), next a phono step-up amplifier and toping all off and completely exposed is Herron's wonderful tubed pre-amplifier.
The reasoning behind these specific component choices was simply to use front-end components likely to be susceptible to airborne pressure and mechanical vibration with probable vibration of the removable shelf, the sheet metal of the CD player and the preamplifier and top these potential trouble spots with the known propensity to vibration induced distortions with tubes. Probably the only way to have a better choice of components to be affected by air borne vibration would be if the Heart tubed CD player plumbed the extreme bottom below forty Hertz such as the Cary does in spades. However the very sturdy (thirty-five pounds) chassis of the Cary tends to resist the effects of direct vibration at sane listening levels and has no tubes and simply did not always illuminate differences in the reviewed products.
Once that was determined it was simply no longer used. At the CES, some manufacturers gave me copies of compilation CDs they use to show off their systems. Some were outstandingly good for the purposes of this review. Unfortunately I still do not know the actual original sources for the tracks I used. Fortunately the truly superb Reference Recording CD/HDCD recording of Copland's Fanfare for the Common Man had a direct and positive correlation with the best of the special CDs I had on hand. Admittedly the effects of the use of the isolation products were not quite as clearly apparent but still routinely demonstrated the results. This was true even though the Heart player does not enjoy the benefits of the HDCD filtering chip. The Cary decodes HDCDs to perfection but then resists the effects of the sound waves so well as to hide product differences - so only the Heart was used - understand? Yes, if its bass response extended a bit deeper, tighter and clearer it would have been even an even better source but we can not expect everything from a sub thousand dollar tubed CD player. As you may remember, it is a very musical sounding player reviewed some time ago by Dick Olsher.
This little project started at the 2003 CES show with the usual demonstration with the IsoBearings (Isolation Globes). This uniquely simple and effective demonstration of this Audio Prism product versus competitors! Competitors have told me privately that they wish they had thought of it first and that it visually sticks in observers' memories. None said, not even privately, that they thought it was any better or even the equal of their products. This impression consists of a simple platform holding a rather heavy hammer up in the air by a dowel running through a hole near the handle end. The hammer is raised and then released and it forcefully falls and hits an IsoBearing. End of story (or demonstration).
With the naked eye, nothing is seen; the hammer unexpectedly does not bounce up. It simply plops down and there is no bounce. Disarmingly simple and visually memorable. Your brain indicates that "wow" that product or the material in that IsoBearing product is really something, dead, inert, unreactive or whatever. Does the demonstration prove anything, anything significant to this review of audio or sound reproduction products? My personal guess is meaningless and my background in this area of physical science is lacking. My guess is that there is no connection, that it is simply an interesting phenomenon. It does impress most people that see it. It must dissipate that force of the hammer blow.
Physically this product is unusual, at least in my experience. The company describes it as a unique ball-in-a-cup isolator offering three layers of isolation and features a round ball made of a proprietary energy-absorbing material riding in a plastic cup designed for maximum support and efficient heat dissipation. The underlined words by me are for emphasis and require a bit of explanation and are not unique to this particular product. Hopefully my very brief comments are accurate enough to help and not confuse readers. Energy such as that which causes vibration in anything including audio products does not simply disappear. It can be transferred or converted/absorbed. Here, as with many other isolation devices, energy absorption or conversion results in heat and heat ultimately needs to be dissipated (transferred). Yes, in a miniature way, a micro-miniature way, the same as an amplifier needs something such as heat sinks or its chassis to dissipate heat. Okay, end of science lesson for now.
Excellent pictures are downloadable from the listed web site. These devices are somehow cuter than the other devices but come as pairs and overall each pair is less than an inch and a half tall. Sold in sets of three, I believe I was the third person in a row to request sets of four. They should offer an option; of course if four sets are purchased, that will take care of three components with four used per component. Many components may require even more than four to be used, as the weight load recommendation seems to be very low. I did not exceed it but I would be surprised if there was not a definite safety or fudge factor in the recommended specifications. You are free to experiment and decide which end should be up from the underlying surface. It can be used often in the depression found in the feet that come with many components - and why not? The use of the IsoBearings resulted in an audible change in the reproduction of musical CD recordings in my system when used under the Heart CD player. This change was definitely an improvement and not simply a change or difference.
It is certainly the place and probably the time for a bit of explanation here. When playing the various test or reference CDs loudly (defined as a volume or gain setting that discourages conversation with someone more than four feet away) the sound pressure waves from the loudspeakers in the bass range are vibrating the CD player directly and "indirectly". Rightly or wrongly I am referring to the shelf or cabinet upon which the CD player is residing, being vibrated and in turn directly (mechanically) vibrating the CD player. Isn't that all the same thing or the same vibration as resulting form the same powerful drum whack or series of whacks? Not quite or not exactly is my considered reply. These sound pressure waves are at least partly absorbed by the shelf or cabinet and dissipated (heat producing) and some of it is stored momentarily and released a minute fraction of a second later thereby prolonging the effect or effects of that loud drum whack! Why oh why does everything seem to get so complicated sooner or later or is it always? That's life or at least audio life. It does not have to be a mystery; answers are out for those willing to search. Essentially all can be explained with a scientific basis in fact. Be suspect of anyone or any product that seems to not follow scientific facts or rules. Too good to be true usually is.
Play around with the products and have fun while comparing. Think and visualize. In the following paragraphs is mention of a seemingly simple base with isolation feet under it. You might think of also placing isolation feet on top to contact the supported component. Why - exactly what do you then expect to happen? Can you visualize a negative aspect to that particular setup?? What if you had a nice piece of home theater furniture? In it is most everything including L, R and C speakers. Where would you start putting isolation devices? Think about it. Would you put them under the loudspeakers? Why or why not. Think and play around - pretend that you have a fun hobby!
Bright Star Audio
As an introduction to the next product I would like to state that there is a great deal of interesting and valuable information available online at the Bright Star Audio website. While there visit the various associated pages listed. I am under the impression that all or almost all was written by Barry Kohan. He ultimately covers more aspects of vibration and its isolation than you might be able to even think of including magnetic repulsion. His thoughts on the magnetic repulsion technique almost exactly paralleled my experience with some prototype models I still have. There are a few statements I still have to figure out or have proven to me. Barry's results, theories and product developments make an excellent starting point for almost anyone trying to figure out this disarmingly complex subject. Kohan's background arose from his work and experience at the generating end of this problem - loudspeakers.
The Bright Star Audio products that Barry sent are their least expensive as befits the stated parameters of this comparative review. The primary items were their bargain priced IsoNode anti-vibration feet (pictured above) available in two sizes. The large size are $19.99 per set of four, are approximately one and a quarter inch in diameter and three quarters of an inch tall and have a recommended component weight of forty two pounds per set. The smaller models are about half as large, have a have recommended component weight of thirty pounds per set and are just $12.50 for a set of four. They have an adhesive backing used to attach them to the underside of components. Often it works out fine to attach them directly to the stock feet if they are sturdy and solidly attached. Slightly superior results as compared with the preceding IsoBearings was particularly noticeable on the initial impact of drum whacks and sense of the mallet striking.
Barry Kohan had sent along examples of their other budget priced items that complement or allow their IsoNode feet to perform at their best. The other products sent were their Little Rock 4 pod (pictured above) and a couple of Bright Star Audio's IsoRock 4 platforms. Think of "Rock" representing solid or inert, "Iso" as meaning isolation and "4" as being a smaller size model. The basic Little Rock 4 is also inert and is meant to be used, without blocking air flow on the chassis tops, to reduce/eliminate the vibration of that typically thin sheet metal top. There are different and easy ways to do that, most notably by using a minimum number of included small rubber stops between them. The only slightly more expensive IsoRock 4 looks like it could be a couple of thinner Little Rock 4s with a thin layer of the IsoNode material sandwiched in between those layers. Turns out to definitely not be true!
The requirements for use under a component and damping on top are unique and different. I was truly surprised but now understand. Someone at Bright Star is obviously doing research. This is then "bottomed off" by the set of IsoNode feet included in this bargain priced and seemingly very effective design. Bright Star Audio also offers the rather well known Big Rock series, the Gemini isolation twins, Air Mass mounts and the Rack of Gibraltar, but all are beyond the scope of this review. Communicate with them about their ideas and products to use under loudspeakers and subwoofers. Maybe I will be fortunate enough to get to try some of those premium devices. Isolation is not just a sideline product for them.
Listening to my system using the bargain priced IsoNode feet resulted in the same general sort of improvement noted above when using the IsoBearings by Audio Prism. Not identically the same results but close. Sometimes careful listening comparisons slightly favored the IsoNode feet in certain drum passages. Placing the Little Rock pod on top of the Heart CD player made for a marginal improvement. That is probably because Heart incorporates a half-hearted attempt at damping the top cover on the inside that evidently does help.
Next I took that Little Rock pod, stuck four IsoNode feet under it and then placed the Heart Player on top. You guessed it, another slight but definite improvement though not quite the equal of using the IsoRock 4. Remember that experimenting such as I just mentioned, puts more weight on the IsoNode feet (or other brands) and should be compensated for if exceeding weight recommendations by more than a few percent. In this case, in addition to switching to the larger IsoNode feet you could use more of the smaller feet. Of course that would be if they are all able to be mounted on exactly the same horizontal plane. If you use six of the devices and are questioned by one of those hobbyists that is still convinced that the number of isolation devices or feet used should be three (as packaged for the IsoBearings) simply tell them the latest recommendation is for "double threes".
Next was a combination of Bright Star Audio items winding up as follows: Under the CD player went the IsoRock 4 which has IsoNode isolation feet, the Little Rock was placed on top of the player and IsoNode feet under the tubed preamplifier. The audible end result went beyond a slight but definite improvement to a significant and noticeable improvement that improved more as the volume or gain control was advanced as was expected. I plan to say a bit more, perhaps in the overall summary, but this setup definitely resulted in the most impact and deepest bass response in the review as well as the cleanest cymbals in some immediately following passages, almost on top of the drum beats.
The SSC Pucks imported by Allen Perkins Immedia Company are decidedly different than any of the other products under review. Neat, attractive, lightweight and two inches in diameter and about five eights inch maximum thickness, they are effective and basically do what they claim. I am still surprised a bit, simply because they are so different. No heavy construction and no typical resilient soft sticky or pliable material such as with IsoNodes or Vibrapod® Isolatorss is readily apparent. These German products are by Akcept Audio and feature their String Suspension Concept (SSC). Two things should be mentioned about the five web sites, picture and information. The pucks are much more attractive than the single picture I located of one. The brief description of how it works is accurate but is not telling you anything. In this application I am telling you that it works, is attractive and simple to use and has an almost unbelievable rated capacity for a set of four well in excess of one hundred pounds!
At a glance it appears to be a nicely finished plastic puck. One side has a quarter dollar size piece of felt (twice as thick as a quarter dollar) in the center. The other side is the same except an additional thin piece of felt covers almost the entire surface of the puck and is between the puck and the aforementioned quarter dollar size felt. It feels as though there may be an opening in the center or middle of the puck for whatever that observation is worth. Overall its performance was not really surpassed by the others. Using another set under the preamplifier at the same time yielded an increase such as with the IsoNodes and adding a Little Rock on the top kind of "frosted the cake" as expected. You may have to dig a bit to find these, as I don't remember seeing advertisements for them or previous mentions. Thanks Sedrick Harris for your insistence that they deserved review.
Vibrapod® Isolators seem to have been around for a long time and somehow snuck onto the scene near the time that the Sorbothane products were popular but much more expensive. At a glance those two and a half inch diameter multi thickness (just over a half inch maximum) devices are a pleasing black disc or puck. In hand the very soft floppy feel seldom impresses people. Sometimes after continued use under the foot of a supported component it distorts the Vibrapod® Isolators so badly that even its mother could not stand to look at it. It seems as though the possibly unique material or simply the varying thickness of the design results in it being more weight sensitive for best results compared to the other products being reviewed. Fortunately a wide range of weight choices are available and their prices are reasonable but no longer are they the cheapest choice.
Listening notes remind me that they were surprisingly good at times almost the equal of the IsoNodes, but not consistently so. I am unable to easily explain the apparent lack of consistency from one recording to another. Putting a set under the pre-amplifier and an IsoRock on top of the CD player, pretty much if not quite completely, yielded the improved results expected.
Quest For Sound Isol-Pads
Last but by no means least of these general types in this review survey of isolation devices is Stephen Monte's Quest for Sound Isol-Pads. The devices are utilitarian appearing which may be off-putting to some consumers but that is curable. At the same time they appear to be close to indestructible under any expected usage. They are two-inch squares with a high impact ribbed rubber surfaces on both sides with a middle sandwiched layer of isolation cork, which is the material that appears "unfinished" to some people. Total thickness is slightly less than one inch. That description fits at least one other product that I have seen advertised and of course this review evaluation does not apply to any other similar appearing products. Each pad is rated to hold up to seventy-five pounds or a total of three hundred pounds for a set of four! As a result, even large loudspeakers could be supported.
Meditate for a minute or at least a moment. Why would that fact be of interest for readers of this review or even be germane to the subject of this review? On a personal level I found that I was harboring an unspoken bias. I found it very difficult to believe that isolation feet/supports/pucks could be equally effective with a ten-pound component or a hundred pound one resting on a set of four. My mind wants to tell me that is not logical and only a sophisticated isolation system could be equally effective with a great variance in the weight being supported to resist vibration effects. Seemingly I am wrong again.
As some famous gourmet, or was it a lousy cook, said that the proof is in the pudding. Well the proof turned out quite well compared to any of the other competitors. Listening notes revealed excellent ranking (no higher ranking available) on the Copland drums and cymbals and excellent for detail on the same recording. Very powerful on the deepest tuned bass drums on some of the specialty recordings and noted as perhaps a tad less clean or detailed as compared to those sticky IsoNodes. Stephen again mentioned to me that many of their dealers are still selling them for well below half the list price - a genuine bargain.
The last devices reviewed are the last ones received. I received from Ultra Systems two sets of four, each set a different size and quality/price rating of their Solid Poly Crystal Equipment Isolators and two sets of four of their Poly Crystal/Brass Speaker Spikes (threaded). These are definitely different critters than all that have gone before in this shootout. The unique polycrystal materials in various particle sizes are in common shapes for the threaded loudspeaker spikes and a "rounded off" but still slightly pointed shape for the so called isolators for electronic components. All the products have an excellent finish and attractive appearance for being black spikes, albeit "high tech ones. There are many who would question the use of the words "isolation or isolator" for any type of audio equipment spikes. The argument would be that the spikes tend to more closely couple things, such as the shelf and component, together and not isolating them. Just some food for thought. If true, then you should think of these spikes/feet as high tech replacement feet for the components.
Used with the Heart player and the tubed pre-amplifier, as with all comparisons done in this review, the resulting sound quality was almost immediately uniquely apparent. The macro dynamics were stunningly vibrant and alive and overall the sound offered a great sense of presence. Very impressive and the sort of thing that would stand out in a showroom demonstration. None of the other isolation devices sounded like this and the logic of that fact sunk in slowly but surely. With some sound systems they might be just what the "audio doctor ordered". In my system it was readily noticeable that micro dynamics were conspicuously absent. It was almost as if they were added to the large-scale dynamics creating a sense of greater gain or volume. Unfortunately fine details also were gone, very fortunately there was seemingly no added harshness or distortion. Audition leisurely and with great care. Used under the superb Alon Thunderbolt subwoofer, the high tech Polycrystal spikes were able to show their worth over the factory-supplied feet.
Random thoughts and a bit of a summary. With the possible exception of the last device mentioned, all these products offered the benefits, to slightly varying degrees of isolation and an improvement to overall sound quality. It was easy to be impressed by the results offered by Barry Kohan's extensive range of products. His Bright Star Audio company has been recognized as a leader, if not the leader, in this field of audio. His Technical Talk writings on the Internet are clear and rather concise, making a surprisingly complicated subject understandable. No wonder when using his IsoNodes feet as part of his IsoRock platform under the player and then a Little Rock damping pod on top of the player the resultant sound quality was not to be equaled. Other companies simply do not import or offer a comparable range of accessory products. Most of them offer only what was reviewed.
It is clear that used alone the fine, separately available, IsoNode anti-vibration feet were almost equaled overall by Stephen Monte's Isol-Pads. They offered a much wider weight bearing range and claimed resistance to marring underlying shelves and a comparable bargain street price. Rounding out the top three is the truly unique SSC Pucks as offered by Allen Perkins and Immedia Sound. They offer a large percentage of each of the advantages mentioned for the above Isol-Pads in a compact attractive package albeit for a bit more money, undoubtedly due to the careful German manufacture and shipping/import costs. The other mentioned products did a truly good job. Instead of thinking about replacing any of them if you are currently using them, give serious consideration to trying those important, not really accessory items offered by Bright Star along with what you have!
This recommendation I can only give for the specific products reviewed. It definitely does not apply to some similar appearing products.
We at Bright Star would like to thank Karl Lozier for writing such a wonderful review of our products. We are proud to be one of the pioneering companies of vibration control in high end audio - we have been a manufacturer of cutting edge designs since 1989.
Our products are designed to deal with all three main sources of harmful vibration:
The basic laws of physics tell us that the vibration's energy is never destroyed, it can only change form. Our products create an effective environment of high absorption around the component to drain away the destructive mechanical energy and change it to benign thermal energy. The dozens of industry awards we have earned over the past fifteen years, including being nominated four times for "Accessory of the Year", twice for "Editor's Choice", "Best of the Year", "Best Buy", "Product of the Year", three times for the "Golden Note" award, five times for "Component of Merit" and many others are a testament to the effectiveness of our designs.
We invite all music lovers to read our philosophy of vibration control by clicking here. You can also view an extensive discussion about the varying degrees of effectiveness of pointed cones, three point mounting, round ball type of devices, the misguided notion of "tuning" vibration, concrete vs. wood floors and many other interesting topics by clicking here. Home theater enthusiasts will also be impressed with the ability of our products to significantly improve the video picture in their systems as well as the audio quality.
For those with loftier ambitions, Bright Star will debut our new IsoRock 3 Reference platform at CES in Las Vegas. This ultimate expression of the IsoRock design employs many of the features from our Reference Series and will enhance the performance of even the highest level components. The IsoRock 3 Reference will sell for $499.
Please feel free to contact me personally with any questions or comments.
Thanks to Steven R. Rochlin and Enjoy the Music.com™ for publishing the review.
Company Information And Prices
Bright Star Audio
Quest for Sound
2133 Bristol Pike
The Vibrapod Company