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  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  (System | Threads | Answers | This Thread)

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11-23-02: Twl
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.
Twl  (System | Reviews | Threads | Answers | This Thread)

11-23-02   Mapleshade likes thick maple, although i suspect it has a si ...   Subaruguru

11-23-02   Twl-at what thickness does marble stop ringing?   Mknowles16

11-23-02: Twl
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.

Twl  (System | Reviews | Threads | Answers | This Thread)

11-24-02   Stone is a terrible choice for hi fi racks, you would get be ...   Rene

11-24-02: Brauser
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.

Brauser  (Threads | Answers | This Thread)

11-24-02: Zaikesman
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.

Zaikesman  (Reviews | Threads | Answers | This Thread)

11-24-02: Albertporter
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.

Albertporter  (System | Threads | Answers | This Thread)

11-25-02   I just put in the lack shelf i got at ikea. two 4" dia. ...   Cdc

11-25-02: Gregm
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

Gregm  (Threads | Answers | This Thread)

11-25-02: Brulee
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.
Brulee  (Threads | Answers | This Thread)

11-25-02   Whats neuance and sistrum?   Ulf

11-25-02   Well brulee, i may not have yet made the plunge to begin ser ...   Zaikesman

11-26-02   Ulf, neaunce is some type of composite shelf that absorbs vi ...   Cdc

11-26-02   Ulf, look into "reviews" for neuance. jadem6 wrote ...   Gregm

11-27-02   Sistrum is a rack system that uses audiopoint cones to suppo ...   Consttraveler

11-27-02: Redkiwi
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.

Redkiwi  (Threads | Answers | This Thread)

11-28-02   Excellent post redkiwi. non-resonant material is critical, i ...   Cdc

11-28-02   Also redkiwi's post seems to say the ceramic foot polishing ...   Cdc

11-28-02   I commend redkiwi on his efforts to form a consistent analys ...   Flex

11-28-02: Albertporter
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.

Albertporter  (System | Threads | Answers | This Thread)

11-29-02   Well, then there's always my approach: i invested about 1k i ...   Zaikesman

11-30-02   Btw, the preceding doesn't mean i'm in love with mdf any mor ...   Zaikesman

12-01-02   Albert, i did not like the neuance on an aluminium rack eith ...   Redkiwi

12-02-02   I have to agree with red on this. i find it interesting that ...   Subaruguru

12-02-02   subaruguru, i suspect that what you are saying and wha ...   Flex

12-02-02: Redkiwi
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.

Redkiwi  (Threads | Answers | This Thread)

12-02-02   I have read ernie's post more thoroughly now and believe he ...   Redkiwi

12-05-02   Flex, there's no way that tightened phase, coherency and pra ...   Subaruguru

12-05-02   I agree ernie that prat is an absolute to be striven for. h ...   Redkiwi

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