Barry recommends a rather clever DIY approach to highlighting the issues of isolation, and provides a clear and affordable way to address them. What you need (at the risk of oversimplification) is both north-bound isolation (up from the floor or rack) and east-west isolation (environmental). To do that, he started with the latter first — building off a simple ball-in-cup (or ball-bearing in an Easter-egg cup holder!) design that “floated” his components and provided good-to-excellent isolation. The effectiveness of the float depends upon the degree of freedom allowed by the interface between the ball and cup — the slower the oscillation of a ball in the cup, the lower in the frequency range that is being isolated. The longer the roll indicates the degree of damping — low damping (long rolls) are better. What you want, then, is a nice, round, very hard ball, sitting in a very smooth, shallow cup. Placing your component directly on the ball/bearing is all you have to do. The component will jiggle when touched, which is disconcerting, but given that there is a limit in the cup (that it’s actually a cup and not a plate, for example), the component will not typically fly off your shelf (or whatever).
Interestingly, VAC uses this approach to isolate the top, en-tube-en-ated, portion of their reference amps from their power supplies, which sit directly below. Rock-a-bye on a $40k amp — I’ve seen Kevin Hayes do this “demo” at an audio show, and it’s always good for a gasp from the crowd.
Okay, so, assuming you’re down with everything on your rack jiggling around like a bowl full of jelly, there’s still a straight line up and down that is ideal for vibration transmission — at a resting state, there is very good coupling. Obviously, this is not the ideal state — which is why Barry recommends adding an additional element to complete the float. In his case, he suggests an “air bearing” to provide that de-coupling along that vertical axis — such as an partially inflated/compressible bicycle inner-tube (or something equivalent) layered between two boards. It’d work like a shock-absorber, adjusting up and down. Think 1970’s Cadillac suspension and you have an idea of what you’re shooting for — smooth ride, baby … smooth …. Anyway, together, the air-bearing and the ball-bearing give 100% of the necessary isolation anyone could possibly want.
So, Easter-egg cups, ball bearings and inner tubes … yeah. Well, if you’re like me, I’m thinking “that’s okay and all, but that would look like ass”, you’ll understand why I immediately started looking for a solution that incorporated those design elements but actually looks like something other than what you’d find in my old college dorm room.
Enter Symposium Acoustics USA.
It’s all ball-bearings these days
Symposium USA’s Peter Bizlewicz sent me a box full of goodies to help address some of these issues. The cornerstone products in the Symposium lineup come from the RollerBlock Series. These are exactly the ball-in-a-cup design that Barry was talking about — and then taken to the n-th degree in terms of fit, finish and function.
There are three levels of bearing, moving toward an ever-reducing level of deviance from perfect. Remember, the goal is roll — anything that impedes that roll, limits the effectiveness of the design. With Symposium, you can take the bearing from a standard chromium steel up to tungsten carbide, a much harder material that experts say performs (rolls, maintains its shape, &c) measurably better.
In 1999, Symposium determined that grade precision – that is, how perfectly round each ball is, and how similar in size each ball is to each other – is of critical importance to performance in ball bearing isolation devices. All Tungsten Carbide balls now supplied by Symposium are Grade 10 precision; off-the-shelf bearings, by comparison, are Grade 100, or 10 times LESS precise. How perfectly round a ball is has a profound effect upon its vibrational characteristics and directly influences the amount of distortion produced (or not produced) by the Rollerblock system as it responds to micro-displacements caused by vibration. The more perfect a ball and the more uniform each ball is, the better the Rollerblock system can respond to vibration, and the less distortion is induced into the electro-mechanical system which the Rollerblock system is protecting.
The ultimate bearing is the Grade 3. This “means that the ball meets guaranteed tolerances of an incredible 3 parts per million, or better. There is no higher grade available at present.” The Cable Company sells them for $115 each.
The bearing sits in a polished cup made from aircraft-grade aluminum. The top-of-the-line cup is the Rollerblock Series 2+, which retails for $399 for a set of 3, and includes the Grade 10 tungsten bearings (that’s what the “+” is for: tungsten bearings). The Series 2+ “chassis” (the thing the cup sits in) is precision cut and machined from a much harder anodized aluminum that what’s in the cup, giving something of a constrained-layer damping effect, one that is assisted by an interior stuffed full of acoustically absorbent material.
The step-down version of the design, the Rollerblock Jr:
Rollerblock Jr. consists of 6 tops and bottoms and 3 center bearings, to make 3 “Double Stacked” isolator/coupler units. Each top and bottom is constructed of black anodized, aircraft alloy aluminum, and has a 1.875″ diameter (4.76 cm) and 5/8″ (1.58 cm) thickness. These dimensions were carefully chosen to make Rollerblock Jr. easy to use and set up, yet strong enough to withstand the rigors of use under heavier equipment such as large amplifiers and heavy loudspeakers. The special cup interior has been designed so that the top and bottom “sandwich” is stable with the ball inserted in the center, making for easy setup. The bottom and top are flat and suitable for all equipment chassis, as well as flat surfaces and carpeting.
If you’re concerned about the stability of your $15k component rocking back and forth on marbles, as in, you’re thinking it might go flying right off the rack when you hit the “open” button on your CD player, the Junior is perfect. With the two cups sandwiching the bearing, there’s nowhere for anything to go. The Junior also includes a 1/4-20 threaded hole dead center on the side of the body that is opposite from the cup. “This threaded hole allows the Rollerblock Jr. body to be screw-mounted to many existing equipment foot fastener systems” — including loudspeakers or other components. I saw this and was thinking specifically of my Magnepans, which I very cleverly kitted out with a loudspeaker brace/stand from Mye Sound — and had threaded for 1/4-20 holes. Retail on the Junior starts at $169 for a set of three; an upgraded version, the “Heavy Duty Special Edition” (HDSE) takes it to $299, uses a much higher grade of aluminum for a much more resistant (to deformation) surface, and also includes the Grade 10 Tungsten bearings.
So now that we have the first part of the “float” taken care of, and all those pesky vibrational anomalies coming from every direction but straight up have been dealt with, well, let’s deal with straight up.
Symposium has a suite of shelves/platforms in a variety of sizes and thicknesses, but they all have a similar approach, and have a similar goal.
All of the surfaces that will contact your components are steel. This may come as something of a surprise, and if you’re suspicious (steel rings!), well, you wouldn’t be alone. So, no, the shelves are not solid steel — they’re also sandwiches, with thin steel plates on the top and bottom. In the middle of the sandwich is acoustically absorbent foam, creating a constrained-layer system. The only thing striking this shelf is going to do is hurt you — there is no ring.
The Svelte Shelf’s very rigid top and bottom layers vibrate more uniformly than less rigid materials, thus transferring more energy to the center section, where it can be dissipated as heat. And because the top is vibrating more uniformly, without “breakup” found in woods and other less rigid materials, there’s less “blurring” of imaging and transient information.
A note about this — the suggested use for the shelf is in direct contact with your component. Yes. Direct contact — no factory footers allowed. Take ’em off. Slap the component — or loudspeaker — directly on the shelf. If you’re using them with Rollerblocks, which is strongly recommended, you put the bearings under the shelf, not on the shelf, so the whole thing jiggles.
If you have little kids, keep them out of the room. If you have cats, shoot them. If you have annoying friends or family members, I’d recommend threats of bodily harm. Now, all that said, speakers on a thin platform on a set of Rollerblock Juniors, all a-jiggle, is still perfectly stable, wildly counter-intuitive as that may be. No, really. There’s this 1/4″ of travel that your component/speaker can make, but that’s it.
Assembling this kind of system might take you an extra pair of hands to do it all, but no need to get twitchy. What I’d recommend is to get the Juniors and go halvsies — bottom cup directly on your carpet or floor, bearing rattling around in the cup, Svelte shelf on a set of bearings, and whatever it is you’re floating directly on that — and Bob’s your uncle. So much for vibrations coming in from the down-below — or the rest of your rack! In fact, you could get a pretty simple Ikea rack, something cheap, and with a Rollerblock + Svelte combo, take the performance to SOTA.
Pricing on the shelves starts at $199 and goes up from there. Don’t sweat it too much — remember, the goal of the design is to get it all snuggly up on the bottom of your component, so you’re really only going to need small shelves. Unless the component you’re trying to float has a bizarrely huge footprint, like my Mye-Stand enabled Magnepans (24″x24″). Whoops. But for the standard audiophile CD player, the smallest Svelte (8″ x 10″) should be fine — just turn it sideways to fit it between the standard feet of the component. Ta-da.
To Wally World!
Okay, so that’s not always an option. Odd footer layouts, aesthetic choices, or whatever — you do have another choice than pulling your footers off (and losing them) or slipping a small shelf in sideways. That’s what the Precision Couplers are all about.
Wait a second! Couplers, you say? Did you say “couplers“? Aren’t we supposed to be de-coupling here?
And that brings me to the last point — yes, we’re still doing decoupling. We’re shooting for float, folks. But while we’ve talked with East-West vibrations with the ball-bearings (Rollerblocks) and North-South vibrations with the air-bearings (Svelte shelves), we really didn’t talk about the South-bound vibrations, specifically. That is, the vibrations in your components themselves.
Transformers hum. Discs spin. Shiznit happens. And all those fancy footers, even the soft, squishy sorbothane ones that eventually dissolve and etch their way into your rack (ask me how I know), they may damp — that corner of the chassis. But slap a Svelte under that base plate of your amp, and you’ve got a lot more surface area that can drain into the shelf.
Okay, so back to the troublesome case-studies. Can’t get a Svelte up against your component/speaker like a beer-cozy? The Precision Couplers are your Huckleberry. These fat, polished, aluminum disks are made to slip between the Svelte and the component. Like the Rollerblock Juniors, they’re also drilled out with a 1/4-20 thread on one side, in case you get squirrelly and want to swap out footers. Not necessary, but hey, it’s about the options. The Couplers are really smooth, too — a fresh-out-of-the-box Coupler placed on a fresh-out-of-the-box Shelf creates a vacuum. I had to work to break the suction to get the damn thing off. Which is pretty much exactly what you want to have happen! Nice coupling …. Again, the constrained-layers are isolating — but now, with the Coupler (or the direct connection by sitting on the Shelf directly) the traffic is two-way, both ambient and component vibrations heading into the middle of the Shelf, where that energy can safely be trapped and converted to something harmless (like heat).
More than famous
So, that’s the story. All bespoke. Bearings, shelves, couplers, ta-freakin’-da. Not cheap, but it looks terrific — and will inspire you to touch your gear. And sing. Watch it wiggle, see it jiggle ….
Some general notes. Steel comes in a variety of hardnesses and the harder the steel, the less likely it is to scratch. Symposium uses soft steel for vibration-mitigation — it needs to be rigid, but not perfectly rigid — and besides, it’s probably cheaper. But whatever — the point is, it’ll scratch. Get over it. If you’re doing it right, you’ll never see the shelf, anyway.
Another thing — if there is a difference between the bearings, it isn’t visually obvious. So if you spring for the Grade 3 balls, keep them separate from the Grade 10. Once you’ve mixed them up, you’re done.
Last thing — the Svelte Shelf is thin. Really thin. Like about half and inch. This is good — slipping platforms under a loudspeaker is a fine way to level up their performance, but it also raises the tweeter height. With some tweeters, this isn’t an issue — but with ribbons or AMT, it can be. Add in a 4″ maple shelf and you’ll need to raise your seat by the same in order to maintain the proper as-designed alignment. Of course, most chairs, couches or chaises don’t really do that … anyway, just something to be aware of.
Be the ball
Okay, so, how did it work?
I should start this by saying that I couldn’t get it to work with my Magnepan 3.7s, at least, not the way I wanted it to. Ideally, I’d have the vibration damping platform directly under the stand and the Rollerblocks under that, but the stand’s footprint is too big for any of the platforms I was sent — oh well. Peter did send me an option, however, which I was able to try out. Instead of one large platform, I had two sets of Point Pods ($149 for a set of three). Not ideal, as the Pods were all of 2″x3″, but I was able to get an equilateral triangle, with the Point Pods as the interface from the bearing to the frame of the stand. Worked. Seemed less stable than it was, obviously, so I added the top of the cup to the Rollerblock Junior, which helped my peace of mind, if nothing else.
If my Maggies had not been all kitted up with the stand from Mye, this might have had a greater impact, but that Mye Stand does a tremendous job of stabilizing and grounding out the vibrations that the big panels make as they work. I believe that the Symposium devices did add something, perhaps an ease to the music, but nothing I could swear to. By contrast, the Svelte + Rollerblock Junior solution work quite the trick with all my stand-mount speakers! I was able to put the combo between my adjustable Reference 3A stands and a pair of Sjöfn Hifi ( the clue ) loudspeakers, a pair of Joseph Audio Pulsars, and a pair of Clearwave 7R and in each case, the performance lift was marked and beneficial. Bass was deeper, faster and cleaner. Mid range material was more transparent and detail retrieval was simply better and more of a piece. The performance gains, here, were sufficient enough to this my default approach to all stand mount speaker systems. Ska-doosh.
Not surprisingly, the results were mixed when I set up various components. Vibration control is a relative thing — not every environment is as troubled and not every component rattles like a coin in a jar — so, as you’d expect, YMMV. $368 per component isn’t an insubstantial investment — your typical outlay would set you back almost $1200 to cover 3 components — an amp, a preamp, and a source — which is still wildly cheaper than some of the top-shelf racks you can get. Obviously, if you’re not tossing around Mitt Romney money, strategy comes in to play here, and you’ll want to start with critical components, like a source. Given my own experiences, I’d do a source and your speakers, and work from there. Those two, sources and speakers, tend to benefit pretty directly. Tube amps show a nice lift, too.