Marble or Granite shelfs in a hifi rack?

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.

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.

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.

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.