Marble or Granite shelfs in a hifi rack?


Im planning to make a simple HIFIrack with marble or Granite shelfs and halfsize bricks in betwheen Is this a good idea?
It will be very heavy (20 or 30mm thicknes?) But will this isolate from vibration or perhaps pick up vibration? I have a wood floor.
If good is marble or granite to prefer?
ulf
It depends upon which frequencies you wish to isolate. Different materials have different characteristics. I know that marble cracks very easily, and that could be a problem. Granite "rings" if it is not real thick. Actually, a very dense wood like Cocobolo is better than either of those stone products.
Mapleshade likes thick maple, although I suspect it has a signature too. I'd just use whatever's easiest and most attractive for you, and then plop Neuance iso/absorb shelves on 'em for perfect isolation. Birch plywood's usually nicely made, and won't sag, unlike MDF. Don't make the mistake of believing that high mass is necessarily better. Marble certainly has a sonic signature, for example.
Make it light and attractive (NOT glass!), then float the Neuances, Rollerblocks or other high quality neutral devices. Have fun.
Twl-At what thickness does marble stop ringing?
Mknowles, I mentioned that Granite has that ringing. I didn't say that marble does. I think that marble, being a sedimentary rock, has more in common with limestone, than with granite. Therefore, I would guess that marble would not ring much, or at all. However, it does break very easily, if it is not supported fully from the bottom. As such, I would not expect it to be suitable for shelving on an audio rack.

As far as granite ringing, I know that 3/8" thick definitely does, and I haven't done specific tests on other thicknesses. I have read some material that referred to granite TT bases causing unwanted resonances.
Stone is a terrible choice for Hi Fi racks, you would get better sound with cardboard and save money
I have had terrific success with thick granite, particularly
in combination with other isolation devices. I've also
tried the 4" in thick maple which I feel is even better.
To take the subject admittedly but interestingly off-topic for a sec, I once bought an unusual gift of a windchime made from shards of a particular kind of obsidian (natural volcanic glass) that forms in 'fingers'. Dangle these pieces from monofilament and they ring like bells, with a very pleasing overtones structure.

Anyway, although I have not experimented with this myself, many audiophiles and manufacturers seem to prefer one of manufactured granite or marble substitutes that are used in kitchen countertops, such as Fountainhead (hope I got that name right?). Presumably these are fabricated using bonding resins that act as damping agents.
At one time I had four slabs of 3 inch machined Granite and used them under amps, preamp and turntable. After experimenting with them (damping) in every possible way, I sold them. Could never completely eliminate the signature they imparted into the music.

Next I tried Neuance shelves, then 2 inch marine plywood shelves laminated with decorative finish, finally settling on 3" solid maple butcher block. I had the top and face covered with Westinghouse brand laminate in a semi flat gray color.

The Maple butcher block probably has a signature as well, it's just more natural sounding in my system. Perhaps trial and error is required for each person to get it right.
I just put in the Lack shelf I got at Ikea. Two 4" dia. brass discs are under the CDP and one brass disc on top. The Lack shelf is supported but 6 tiny brass spikes which have "o-ring" under them. The 6 tiny spikes then fit into the shelf holes of my Sound Organisation rack. The o-rings space the spikes from the steel shelf frame.

Trying to find small differences irritate me (at least tonight) but my initial impressions are:
- Lower frequencies are more articulate.
- Hall ambience is more audible.
- There are some strange and very unmusical resonances. Meaning some instruments have strange harmonics that aren't at all natural.

So does not seem to be a clear win-win situation. Maple sounds like a good idea. I think the goal is for NATURAL resonances - if you're going to have any.
If it were b/ween the two, I'd rule out marble & try granite instead. Particularly for a suspended wood floor. BUT, things are as Twl explained & all other have illustrated, i.e. which frequencies are you acting upon & what compromises are you ready to make (i.e. acting in one direction can bring along unwanted effects from a totally different direction).

Among others here, Jadem6 & Redkiwi have spent a LOT of time trying all available materials under the sun under their components :)! Maybe they can add an idea or two... Cheers
Granite, marble, glass, maple, all have a sound that some may like for reasons other than being accurate. MDF is a as bad as anything I have used. I have used all of these that I have mentioned and many more. Neuance and Sistrum made a joke of all the materials i have used in the past. They make my system sound like music. They may not be perfect but compared to all the other materials I have used I find much less colorations in sound.
Whats Neuance and Sistrum?
Well Brulee, I may not have yet made the plunge to begin seriously investigating alternatives, but I can agree with you about MDF. I suppose there may be worse materials one could employ, but on the whole I think the entire MDF paradigm is basically a scam rack makers (and retailers like Audio Advisor) have attempted to perpetrate on audiophiles in order to get away with using an easy and cheap shelf material.
Ulf, Neaunce is some type of composite shelf that absorbs vibration from floor and the component. If you dfo a search there was a long thread a month or two ago.
Ulf, look into "reviews" for Neuance. Jadem6 wrote a detailed report.
Sistrum is a rack system that uses Audiopoint cones to support the components. It channels vibes away from the components and out through the rack (no dampening, just removal). There is a review of it on Stereo Times web site, and the home page for Sistrum is on Star Sound Systems.
Here is what I believe.

In theory the best shelf will achieve two, mutually exclusive things. First that it is light and rigid. Second that it is damped.

Light and rigid is vital to ensure vibration energy is dissipated quickly. If you use a heavy shelf then energy will be stored and released slowly thereby smearing the music in the time domain. Some people like this effect since it results in a weightier bass, albeit less articulate and with incorrect pitch. If you use a floppy shelf you will get a similar effect, but that will be more focussed on a single frequency than a more rigid shelf. The "easy to come by" light and rigid shelves, such as glass are still fairly heavy, and they tend to ring badly.

Damped is important to avoid the release of energy being focussed on one frequency range. This is the problem when you use stuff like glass, granite, acrylic and corian. Corian is the best of these but smears the bass and still has a resonant peak. Those shelves that are not well damped tend to need to sit on bumpers rather than spikes - simply to avoid the resonances in the metal rack setting off resonances in the shelf. But the problem is that in not using spikes you will get more smearing of the sound due to energy storge in the rack.

So the ideal is a very rigidly welded steel rack (check that welding is more than one tack weld per join), spiked onto the floor; spikes screwed into the rack, supporting the shelf. The rack would ideally be put together with non-uniform shape - which is the principle that Sistrum focusses on. The shelf would be an ideal blend of light, rigid and damped - which is the ideal that Neuance aims for, and does a pretty good job of.

There are many shelf products and isolation devices that go in a different direction altogether. For example there are the Symposium style heavy and heavily damped products, which aim for neutrality and black background, but give up on speed. If your musical values include PRAT, then do not go this path. By the way I reckon a lack of understanding of PRAT is the principle reason for boring music systems. Many audiophiles listen for impact, detail and neutrality, but find it hard to listen for PRAT. PRAT is all about whether or not your system can communicate the rhythm and swing in the music and tends to require minimum smearing of transients, which tends to be most damaged by heavy support shelves and racks. The reference to Maple above is a decent example of this - the sound is reasonably neutral, but the mass means PRAT is badly compromised. I think PRAT is overlooked because in our straining to hear differences between stuff, we focus on the most easily discerned differences which are tonal colorations, impact and detail.

There are also many footer products that try to compensate for a bad rack. The hard footers are OK but are not very neutral and only have a significantly beneficial effect when you have put too much mass in your shelf/rack. The soft footers suffer the same problem as the 'less than rigid' shelf - they channel energy into a frequency range. Many of these claim, as do the bladder products, to channel the energy into very low frequencies that do not affect the sound. They do not affect neutrality, or detail, but they generally sound 'swimmy' and indistinct - in my opinion because they allow lateral movement, which is the worst form of energy for stereo equipment in my experience.

So the simple message is that Granite is way too expensive for its performance as a shelf, and I recommend you look elsewhere.
Excellent post Redkiwi. Non-resonant material is critical, I think. Maybe more important than absorbing vibrations.

Resonance is the natural frequency of a material. I'm thinking when music hits this frequency it will sound very unnatural. Or worse, this resonant frequency could be in the music all the time making strange tonality etc.
Resonances are much greater in intensity than vibrations coming through the floor etc. which are not at the resonant frequency of the base / component / etc.. So I'm thinking this is the first problem that needs to be fixed. Isolation is secondary.

While air bladders and sorbothane may absorb vibrations they are not a rigid mounting base and I'm guessing could create resonances or bad vibrations at some other frequency.

Noting Redkiwi's caution with Maple, maple seems pretty non-resonant and it is hard (compared to rubber or air bladders). So my next experiment will be setting the CDP directly onto 2) 2-3" wide x 1- 1 1/2" thick hardwood like maple.

Why bother with footers which just cost money and could add resonances of their own? I think direct coupling the CDP to the wood would be better. Large contact area / direct transfer. Also mass load the CDP with brass on top or brass sitting on wood sitting on CDP.
Also Redkiwi's post seems to say the ceramic foot polishing stones in the beauty section of Wal-Mart are the perfect footer solution.
I commend Redkiwi on his efforts to form a consistent analysis of vibration and its effects, based on years of experimentation with different materials and theories. I don't disagree with his anaylsis but would add an important caveat - that you test your own equipment on the types and kinds of platforms before going wholesale for one approach or another.

I own a Spectral system, with mostly MIT a/c treatment and cables, including isolation transformers on each of the 3 front end components (transport,dac, preamp). I use Zoethecus equipment stands (hard maple; heavy, layered, damped shelves of several grades;some shot fill in the legs) that I acquired 10 years ago when I first got into Spectral, and sold routinely by most U.S. Spectral dealers. I don't know whether Spectral is 'voiced' on Zoethecus or not. I also own several Symposium ultra's (heavy, damped), several Neuance shelves (light rigid), and any number of cones, shelves, and hats, and have played extensively with combinations of all of the above, plus other stands, over numerous years.

Spectral/MIT is a solid state system designed as very wide band and very detailed. My current system, using Symposium ultras as amp stands and basically Zoethecus equipment racks, has simply outstanding PRAT. It is also very musical, relaxed and non-edgy for solid state.

I find that there are any number of ways to drive the system into being far too analytic, and this almost always means the intensification of high frequencies to the point of non-listenability. Cones, the wrong stands (in my experience, Grand Prix for example), the wrong choice of rack material under individual components can kill the system sound. This is one reason why I think many people post about systems like Spectral sounding too analytic in some dealerships. Retail dealerships don't have the time to fuss with refining the system sound to the nth degree.

Unfortunately, products like Neuance shelves, which are broadband and not peaky in themselves, still have the effect of intensifying high frequencies, presumably by eliminating far more vibration than shelves like the denser Zoethecus shelves do. (Neuance in this case is used as a supplementary shelf sitting on top of upturned cones atop any of the Zoethecus regular shelves, or in place of Zoethecus shelves altogether, or sitting on the floor on top of cones. It is also a general result pertaining to use of Neuance with the preamp, power supplies, and a/c treatment (the places where it has the most effect.)

I am not posting this in order to criticize Neuance, which I have found very useful with, for example, less exemplary players than Spectral, or to imply that detailed solid state gear has too many high frequencies as part of the signature that need to be 'smeared away' with vibration. (Although isolation transformers produce some inherent high frequencies of their own, which may be part of the problem.) The point is to say, again, do characterize your own equipment and its properties regarding vibration, prat, musicality etc. This is also part of the fun in understanding audio equipment.
Flex, if you're saying that the Neuance shelves don't work for you, that's the same results I had. Placed under my Io (all tube) phono stage, the system went completely lifeless.

What does work is the custom aluminum stand I had constructed, with stainless steel spikes to my slate floor. On top of the four post stand is four mod squad soft shoes (EAR group manufactured). On the squad feet sit a 2" slab of granite. On the granite is 12 of the smaller ISO Bearings, and on the ISO Bearings sits my phono stage. On top of the phono stage sits a 6 pound plastic box filled with lead shot and wrapped with layers of black cloth tape.

This combination has wonderful dynamics, is immune to foot falls and the sonic attack of my large speakers, which sit less than twelve feet in front of the stand.

My opinion is that every room and every type of equipment is different in the personality it presents when matched to various materials. The granite used here for instance, when substituted with maple butcher block, looses dynamics. When the granite is removed and the phono stage is coupled directly to the stand with mod squad feet, Walker cones or other direct coupling methods, the isolation is not near as good.

I am not advocating that everyone follow my set up. I am saying that there is not a universal truth as to what will work with every piece of equipment in every room. Best that each takes a bit from the forums and experiments to find what works.
Well, then there's always my approach: I invested about 1K in my Salamander Synergy Twin 40 solely for the reasons of convenience in having adjustable shelf heights, enough space for all my components, and the ease of system reconfiguring that comes with having gotten the Saturn caster option. The shelves are all MDF, the rack itself is fairly flexible and resonant by high end standards (though much better than some more makeshift solutions or mass-market stuff, and heavy as a bear), and way too tall for high rigidity anyway, and of course it isn't positively coupled to the floor, though the fact that the casters employ rubber treads does provide a little isolation.

Frankly, in my circa-$15K system, I've never heard enough differences from various support strategies with most components to place a higher emphasis on this subject. I do own some cones and isolation footers, finding the Iso-Bearings and such mildly useful with certain gear, and don't use the cones. I keep my TT on an original Symposium shelf, which in conjunction with sorbothane pucks underneath, does a very nice job of isolation from energy transmitted through the rack. But I'll tell you what, I'm lovin' life these days with all my gear on one rack and total accesss from all sides (no doors, sides, or rear panel installed) - I probably roll the rack out and make changes (most temporary) around back a few times a week on average, now that this is so quickly and painlessly accomplished. I have decided to replace all the regular corner shelf support brackets with the heavy-duty ones, which employ steel struts that runs front to back between the vertical pillars, for the addtional reinforcing effect they will have on the overall rigidity, but aside from that, I've experienced no objectionable problems in use so far, and I think I'm done with this aspect.

Could it sound better? What do I care - it sounds good enough for me to just relax and enjoy the music, and the ease of use I get with being able to raise or lower shelves and move the whole thing around at will. I personally doubt that any incremental sonic improvements I might get from compulsively obsessing over a more audiophile-approved and tweaked-out arrangement would be worth the candle to me in terms of livability lost. (Oh, and I also don't believe in the concept of "mechanical diodes", self-vibration being more of an issue than acoustically-induced vibration, or the existence of "PRAT", but those are probably issues best left for other threads! :-)
BTW, the preceding doesn't mean I'm in love with MDF any more than I implied two posts ago, just that although I have mused about experimenting with replacing a shelf or two with something else and seeing what turns up, so far I haven't felt compelled to go to this length. The rack probably doesn't justify it anyway. (Ignorance is bliss and all that... :-)
Albert, I did not like the Neuance on an aluminium rack either. I have played with aluminium racks with only a little success, finding that if you have a concrete slab floor, either an aluminium rack, or a steel rack filled with fine sand were possibly better, whereas on a wooden floor a welded steel rack, unfilled, seemed always better.

You are quite right to say there are no universal truths. In particular, turntables, CDs and valve preamps differ in the ways that they are constructed to deal internally with vibrations and so can respond differently to different supports. But with solid state preamps, and amps of any persuasion, I have found the steel rack and Neuance, plus EAR footers has been superior for PRAT and neutrality in several systems. What I believe is much less universal is the degree to which we audiophiles seek PRAT, or agree on what it is. I have had no experience of any heavy shelf approaching the PRAT of a lighter shelf.
I have to agree with Red on this. I find it interesting that the Spectral user finds the Neuance shelves to accentuate the high frequencies. I suspect that what's happening is that the absence of smear and lower-frequency resonances results in a "tighter" (better PRaT, more coherent) presentation that shows the leanness many of us believe the Spectral stuff is voiced to have. I would suggest that room placement and choice of speakers be used to balance a Spectral system, rather than using "muddying" supports.
It IS true that introduction of Neuance shelves under my CDP (EMC-1 MkII) and pre (Aleph P) helped to heighten PRaT, and that quickness and light-footedness can sound leaner as other components' grainniness or edginess is brought into focus. The Neuance allowed me to hear the difference between cables, ICs, and PCs more clearly, and is now allowing me to use a neutral and very fast cable (SPM), for example, as ALL these links become clearer, faster, and less phasey. Neuance really did allow me to "neutralize" any effect of an underlying base material, when set on upturned spikes. I find this aspect more appealing both scientifically and musically than trying to "marry" one of a myriad of base materials to my system's perceived flaws, imbalances, or "character". The Neuance has allowed a predictable and satisfying evolution of my system without a misstep. If I want to change spectral tilt I'll play with speaker/room issues, NOT support hardware. I know I sound like a devotee here, but I love elegant, successful, cost-effective technical solutions to complex problems! Cheers.
Subaruguru, I suspect that what you are saying and what I am saying are in agreement. I am familiar with the prat, lightness, and also leaning out effect of Neuance. I believe, without supporting measurements to say so, that Spectral/MIT is ALREADY more time and phase coherent than most other designs. Neuance helps to move other equipment toward the same coherency and resolution by eliminating smear of the signal. The leaness of the signal that you speak of with Neuance, and that you also attribute to Spectral, may be an inherent result of tightened time/phase coherency.
This is not our understanding of live music. Fullness, bloom, continuity are normal in live music but we are discussing recorded cd's, wherein an entire chain of recording and playback electronics have acted on the signal. It is possible that tight coherency in all aspects of playback equipment can be carried too far, to the point that low level distortions, filter artifacts, a/c line noise, transformer artifacts, and digititis in cd's may be resolved and amplified.
Also, I mention Spectral/MIT as an entity. Neuance has the greatest effect on power supplies, preamp, and a/c filters, The first group of components may be more subject to transformer artifacts than the latter.
Changing speaker placement, speaker choice, or room treatment won't eliminate a need in the end to deal with vibration and a/c. I'm speaking about small refinements to a system whose character I already enjoy and prefer.
Just to get back to the original question for a moment - and not discounting my belief in the Neuance approach - my experience with Marble versus Granite depended a lot on the Marble being used. Fortunately, for once, the cheapest Marble sounded the best. The cheapest Marble has the most impurities in it and the glass-like ringing of the Marble is much reduced.

Compared with the ringing of Marble, I found the ringing of Granite to be more of a 'boing' than a 'ting', if you know what I mean, a heavier slower sound than the Marble, but this varies by thickness. The use of soft footers between the shelf and the Marble/Granite, as suggested by Albert is the best configuration I could find with these materials. The EAR feet are good, but a friend tells me he has swapped the EAR for another compound that he says damps the ringing more effectively. I am taking a couple of Neuance shelves around to his place shortly and so if the compound is readily available I will report back.

In the end I preferred the Marble over the Granite.
I have read Ernie's post more thoroughly now and believe he is saying something quite important.

Introducing any new component to an existing system is a big ask since if it replaces something that is say bright, then it will sound relatively dull. Does that mean the new component is dull? Not necessarily.

In my philosophy of how to put a system together, I believe that you want as many components (I include cables, supports etc into this) to be "honest brokers" of sound. This is for two reasons. The first is simply that I believe the sound will be better when most components are "honest brokers" than when we mix flavoured components together to try and get a system to be an "honest broker". The second is that you are in a better position to improve the system component by component if each component is an "honest broker" of sound.

I use the term "honest broker" to mean a wider range of issues than just tonal neutrality, such as phase issues, PRAT and dynamics.

I reckon Ernie is saying something that very much accords with my view that in the Neuance, I have found a shelf that appears to be an "honest broker". Hence it is a uniquely valuable thing to build a system around. I may very well be wrong here. The establishment of whether a single component is an "honest broker" of sound is fraught with problems since an individual component can never be heard on its own.

But if I am right it should come as no surprise that introducing an "honest broker" into an established system may cause it to tell the truth about the rest of the system.

But there is no way that I can prove to you the Neuance is an "honest broker" of sound. Only say that it appears to be one, to me, and I have tried the Neuance in several systems.

I can certainly agree that the shelf itself cannot be considered in isolation. Presumably the best shelf for a plastic cased component will differ from a steel cased component will differ from an aluminium cased component, etc, and a component that rigidly couples the circuit board to the case will differ from a component that rubber mounts the circuit board etc, and a component that has moving parts will differ from one that just has electronic parts, etc.

In my experience the Neuance works well with an appropriate rack in most circumstances, and the main variations occur with turntables, CD Players and valve preamps. I would add however, that your own personal values come into it. I have tried the Neuance in two systems where though I preferred the Neuance, the owner did not. In both cases the owner preferred the bass presentation of using a heavier shelf. In my opinion the Neuance is more correct and musical in the bass - being faster, more rhythmical and with more slam at the front of the note. The downside for the owners of the systems was the apparent loss of weight.
Flex, there's NO WAY that tightened phase, coherency and PRaT can be carried too far! I'm being a bit of a devil's advocate here for sake of lively discussion. You defend (it's ok) the Spectral as ALREADY having great coherence and PRaT, and that the Neuance only helps LESSER equipment. I beg to differ.
The Neuance can't possibly effect the electrical design excellence of an amp or processor, but it CAN keep out spurious and as well as corellated vibes. The PRaT/coherence continuum we aspire to in recorded music reproduction is indeed asymtotic, and not center (or other)-balanced! In other words live music doesn't have an "ideal" coherence or PRaT that can be exceeded by too much "coherent" componentry in its reproduction. You gan only get closer and closer with MORE PRaT-ful links in the chain, approaching the live event's infinite PRaT-fulness, if you will allow me the language stretch.
Perhaps you're confusing ambient acoustic issues with PRaT.
I certainly agree that a "live" musical event outdoors, for example, is way too dry because of absence of near reflections and far reflections (ambience and ideal reverberation decay envelope). Similarly a vocalist in a large stone cathedral with mics in the farfield is as "PRaT"-less as can be imagined. But that's not what we're talking about. The degree of reflected energy, and its timeliness, is decided by the recording engineer, and is locked into the "software". A really "PRaT"-ful system will attempt to retrieve that event with the least amount of smear, if you will. Sure, a "bloomier, rounder" system can muddy up an overly-dry recording, but who wants that?
We're talking about time here, NOT frequency response or spectral tilt. The Neuance is one of those "pretty honest brokers" that isolates the component from outside vibrations that smear the presentation temporally,
and possibly excite resonance(s) that excite(s) a spectral coloration. The Neuance thankfully imparts no coloration of its own, as far as I can tell. It snaps everything into focus, including upstream detritus. If such focusing detracts from musical enjoyment because your CDP has digititis, or your amp chain is too lean (can that be?), or your metal domes are just too searing, then don't blame the messenger. An isolation/support device to my thinking should NOT impart a tonal coloration or tilt, nor should it in any way alter (distort) the signal's temporal coherence.
OK, I'll relax now. Cheers.
I agree Ernie that PRAT is an absolute to be striven for. However, some components have tried to be more PRAT-like by actually smearing upper-mids and/or lower treble, creating an emphasis on the attack of percussion instruments, creating a pacey sound but also a relentlessness (I am referring to some of the poorer stuff of some years ago from Naim and others), that may have given PRAT a bad name or created misconceptions as to what it is.

Ernie quite rightly refers to it as temporal accuracy. Those of us that listen for PRAT are trying to find the gear that lets us groove to the timing cues in the music not just the sounds. From much wasted time playing around with supports I discovered (what should have been an obvious) conclusion that a light and rigid support would release its energy faster and therefore do the least damage to temporal accuracy. What is unusual (but there are others that produce similar shelves) about Neuance is that in addition to being very light and sufficiently rigid (provided you buy the right grade for the weight of your component), it is quite damped without the damping causing delayed energy release into the component. I suspect the trick is in how the damping is achieved.

Two other products I used some years ago were quite successful in this regard too. I think both came from Russ Andrews - they were the Torlyte shelves (a wooden honeycomb) that did wonders for my Linn LP12, and Aerolam (aluminium honeycomb) which I never tried as a shelf but did have speakers that used Aerolam for the cabinet.