Ingress Audio Engineering

@geoffkait, by "secrets" I meant how your springs differ from the commonly-available, off-the-shelf springs. I doubt you make them yourself, but you do cryogenetically freeze them. Anything else you care to divulge? ;-) Not that I expect you to; I wouldn’t!

In one of his video (viewable on You Tube), Max Townshend demonstrates the difference between his Seismic Pod and a bare spring of the same rate. Very interesting.

No offence taken, perhaps because I don't know what you meant ;-) .

Say, are ya gonna tell us why the roller bearing is no good for isolating a turntable? I haven't come up with anything better than the spinning moving mass of the platter pulling the ball bearings in the direction it is spinning (clockwise).

@uberwaltz and @elizabeth, the idea I came up with when I first saw Barry Diament's big Maggies on roller bearings, but transferred to my carpeted room and the pair of Tympani IVa I thought I would be able to shoehorn into that room (alas, that was not possible :-( ) was this:

Make a base plate out of Maple/Baltic Birch plywood/etc., and install three spikes in it to raise it off the carpet enough to make it stable (three is inherently stable, four a chore), and level it. Mount the Maggie feet/stand/base plate onto a similar piece of wood (may as well make it the same size as the one on the floor), and place the wood-mounted Maggie on top of the base plate/bottom piece of wood, with a trio of roller bearings between the two boards.

The same can be done with Geoff's springs, or even with both, using another board. Wood is cheap!

In looking at the diagram blowup of the GAIA on the IsoAcoustic website, I came to the conclusion that whatever isolation they are providing must be by way of some sort of rubber. They say it's not Sorbothane, but may it be Navcom? That stuff is still being made, and is used in firearms and other fields as mechanical dampers. I doubt it's the EAR rubber, but who knows?

I hope it's not, as the isolation properties of rubber doesn't extend very low in frequency, which is what we want. The lower the better. But remember when everyone ditched the springs in their VPI HW-19 tables for the SIMS Silencer Navcom pucks? Not all springs are created equal, and I don't think Geoff is going to share his secrets!

If I had the dough, I'd have a Herzan or Minus K under everything. Audiogoner folkfreak has his table on a Herzan (he had me over for a listen), and it's a thing of beauty! 

@uberwaltz, Barry Diament wrote that the roller bearings made more difference under his Maggie 20.7’s than under his electronics. But then he uses all solid state stuff, and records in digital. He uses the 20.7’s as monitors! You can see them on his website. He bolted the stock Maggie feet onto a 2’ square piece of plywood, then put a trio of bearings under the plywood. What I wonder is if he puts the bearing cups right on his carpeted floor, or on top of something else.

I have my Eminent Technology LFT-8b’s bolted onto Sound Anchor stands, which are a tripod design (inherently more stable than four feet, as found on loudspeaker outriggers). The SA’s come with spikes, but a set of roller bearings, GAIA’s, or Townshend Audio Seismic Pods can easily be substituted, which is what I intend to do. The Pods would run about $600, the GAIA II’s (good up to 120 lbs.) also $600 (they come in packs of four, so I would have two left for some other application), the Ingress V.2 only $140 if used single-cup style. The V.2 plus a set of Geoff’s springs would make a great budget isolation system. @geoffkait, how do you recommend your springs be partnered with roller bearings? I may just use my Symposium Jr’s, double cup style, therefore not having to be concerned about the LFT’s rolling off the bearings!

@redlenses03, if you want pneumatic isolation, and don’t mind spending a little money and time, you can keep your eyes open for the old Townshend Audio Seismic Sink platforms that were made in the 90’s-00’s. There were a few different versions, but they all shared the same basic design: an inner tube inside a top and bottom steel plate structure. The inner tube is inflated just enough to keep the top and bottom plates from touching; the lower the P.S.I., the lower the resonant frequency and the greater the isolation. A set of roller bearing on top of a Seismic Sink provides isolation is all planes.

Or, you can get the current Townshend Audio Seismic pods, but they’re around $100 each. Sets of Pods for a complete system can add up to quite a bit of money. But then two sets of the IsoAcoustic Gaia I’’s---enough for a pair of heavy loudspeakers---will cost you $1200, more than two sets of the Pods. The GAIA II is $600 for two sets, the GAIA III $400. Not too bad if you have light (under 70 lbs.) speakers.

So true @uberwaltz. For not much $, one can substitute harder, smoother tungsten carbide ball bearings for the stock steel balls. Symposium charges a small fortune for them, but they are available from ball bearing vendors for far cheaper.

By the way, whether or not anyone thinks the original Ingress was a "knock-off" of the Symposium Roller Block Jr., Symposium was in 1997 granted a patent for the "double-stack" design used in both bearings.

Heck, the Ingress Level 2 V2 is $95 CAD for a set of three cups and ball bearings. It is superior to the twice-as-much Symposium Roller Block Jr., and WAY cheaper than even a single Stillpoints foot.

Geoff, I’m going to guess the spinning platter of turntables is the argument to be made against employing roller bearings under them. CD/SACD players also have spinning platters, but of much less moving mass.

Geoff's excellent post has refreshed my memory. The concept of the roller bearing is a compromise between maximum isolation capabilities, and practical considerations. A set of three ball bearings between two flat, very hard, very smooth surfaces would provide the maximum isolation possible. Those surfaces could be the bottom of the component to be isolated (or something harder and smoother than it, onto which the component is placed---no rubber feet; put something with no compliance between the component bottom and the surface. Barry Diament recommends ceramic tiles, available for pennies at home stores) and another flat, hard, smooth surface (again, that could be a ceramic tile). But that would make possible the component sliding right off the rack or shelf it is sitting on.

For practical considerations, a pair of bowl-shaped structures are used in place of the flat ones; the bowl of course makes the component sliding off the ball bearings impossible. Now, the shallower the incline in the bowl, the better the isolation. When the ball bearings are presented with vibrations, they move microscopically, being forced to climb the incline of the bowl. The bowls' incline thwarting the movement of the ball bearings creates damping, a thing very different from isolation. So, the shallower the bowl, the gentler the incline, and the greater the isolation. That's why the larger bowl carved into the Ingress cups makes them superior in design to the Symposium.

The original Symposium Roller Block used cups on only the bottom, with the ball bearing in each of the three cups contacting the flat surface of the component to be isolated (Symposium makes little stainless steel plates for use under components, for the ball bearing to slide across). The Roller Block Jr. (and the original Ingress) used a cup on both the bottom and top, the ball bearing keeping them apart from one another. Barry's Hip Joint design called for a bowl on only the bottom, for maximum isolation. A cup on the top does, however, provide insurance against the component sliding of the bottom cup. If you want to play it safe, go with the double-bowl design.

The degree of hardness and smoothness of the bowl also effects its' isolation capabilities, the harder and smoother the better. That's why the 7075 aluminum of the Ingress V.2 and V.3 is superior to those made of the softer 6061. The V.2 and 3 all also polished with finer grit than other bearings.

As for cost, the bearings are sold in sets of three. Those sets are far cheaper than even one footer offered by other companies making isolation products. I agree with @rsf507, they ARE dirt cheap!

@mewsickbuff, I can help ya’ll. Not that I want the credit, but it may have been I who brought Ingress Engineering to the attention of Audiogoners a few years back. I had read Barry Diament’s writings on the subject of isolation, and found his argument persuasive. So I bought myself a couple of sets of the Symposium Acoustics’ Roller Block Jr’s. They are a fine product (as are all of SA’s), but I couldn’t help noticing that the design of the Jr. was quite a bit different than Barry’s Hip Joint design. In contrast, the much higher priced "original" Roller Block did adhere to Barry’s idea of a single cup and ball bearing.

So I did some more investigating, and came upon a forum upon which Barry’s ideas were being discussed. I was not alone in my quest for perfection! A group of DIY’ers had come to the attention of Michael of Ingress Engineering. He was making what was essentially a knock-off of the Symposium Jr. (no offence Michael ;-), and selling his version for about half the price of the Symposium. The only difference I could see was the Ingress wasn’t anodized black, being just natural aluminum. The Ingress was about 1.5" in diameter to the Symposium’s 1.875", no big deal. The diameter of the bowl appeared to be identical, so I ordered some. Sure enough, the two were essentially the same. They were both made of 6061 aluminum, and polished smooth. Since the Ingress is non-anodized, you can see your reflection in the bowl!

But being perfectionists, forum members pointed out to Michael that Barry’s Hip Joint design called for a much larger bowl to be carved into the cup. The larger the bowl, the shallower the incline the ball bearing must climb when confronted with vibration (the basic idea of roller bearing isolation), and the lower the resonant frequency and greater isolation does the roller bearing provide. Barry’s design also was just a single cup with a ball bearing, not the cup-over-a-cup design of both the Symposium Jr. and the Ingress. To his credit, Michael went to work and created a second model, one just as Barry Diament had described and machined locally for himself.

The second model was a single cup, with a bowl of much larger diameter carved into the cup. The cup was machined out of the harder 7075 aluminum, and polished to a finer degree. Now we’re talkin’! I got myself a set of those, and man are they great! At the time Michael was selling the new model for just a little more than the original; only one cup cut down on cost, but the 7075 aluminum cost more, as does the time and effort expended polishing the bowl to a smoother, more friction-free finish.

Now having all the roller bearings I needed for my system, I stopped paying attention. Your post lead me back to the Ingress Engineering website, and I see Michael is currently offering two models (plus a larger one for loudspeakers), the improved one now called Mk.2, an even newer one MK.3. Both are single cup of the same size, both machined out of 7075 aluminum, and both have the same size bowl. The cheaper one is anodized black, so I’m assuming the pricier one has been polished smoother, but that’s just a guess. I have no apprehension in recommending either, or both! Buy a set of each, and compare them for yourself. You may end up with the pricier one under your source component, the cheaper under your pre-amp.

I'll beat Geoff Kait to the punch by pointing out that the roller bearing provides isolation in all planes but the vertical. In the vertical, it acts a coupler, not an isolator. To get isolation in that plane, you must look elsewhere. Geoff just happens to sell cute little springs which will do that for you ;-).