Jim, It is my experience that hard surfaces like marble, granite and glass are not the best thing for sound quality.
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Thick slab should be OK. If you don't like the sound of the marble slab when struck with a small hammer, I suggest not striking it with a hammer when the music is playing. The advantage of a thick slab is its stiffness - resistance to bending forces produced by seismic vibration. Besides, no harm in trying it as price of purchasing such a size and thickness marble slab is very high.
Depends. The term 'deadening device' speaks to resonance frequency, and all 'things' have a resonance frequency. Resonant frequency of materials is a function of mass, shape, and modulus of elasticity, not just the material itself. As relates to 'deadening', the lower the resonance frequency, the better. Best to just try the marble and see what if any improvement, or not, in sound results. One thing you don't want to use, that is glass, in any shape or form. Ideally wood seems to be best suited to be used in platforms of audio equipment, the thicker the better. Maple gets a lot of use in high end audio platforms.
from my experience with marble I am with Geoffkait on this one - a thick slab of marble (which is 2" thick in your case) should be a good material to damp the vibrations. On its own marble (& granite) ring like crazy when struck (as Geoffkait indicated) so the key is not to suspend marble or granite by itself (for ex. use marble or granite as a shelf in an audio rack). you are doing the right thing by placing marble on top of a wooden surface (your plant table). this will prevent the marble from ringing. I suggest, further, that you place a 3mm cork sheet (you can buy a roll of cork from Staples & cut it to size with a scissors) in between your plant table wooden surface & the under-side of the marble slab. This will for sure deaden the marble (if there was even an outside chance that it would ring when placed on a wooden surface) & the cork is another fantastic material to deaden vibrations. I've used a marble tile on top of my CD player w/ a cork sheet in between - works great!
Thanks to those who have responded so far. I have accomplished situating the marble slab onto the wooden plant table which is 50 inches long. The mothering slab must weigh about 100 lbs. I am praying it will not collapse the table, but the latter seems fairly strong. I also transferred the components to the table....looks sharp, but hope it sounds good.
To Cymbop , I was just about to reach for the Mapleshade catalogue to see what they offer in footers...both brass and wood. The footers are going to have to support at least 30 lbs each. The slab is 2 inches wider than the table width so I will have to position any footer in approx. that far to get good balance and security.
To Bombaywalla, Interesting suggestion about the cork, though 3mm does not seem very thick, still sounds like a good idea.
I am done for the day; I will rehook everything up tomorrow and provide a report about the results. Thanks, Jim
To Bombaywalla, Interesting suggestion about the cork, though 3mm does not seem very thick, still sounds like a good idea.I've used the 3mm cork mat for damping vibrations on top of a CD player. Also several TTs use this same thickness mat on their platters.
I am also using this 3mm cork mat on my amplifier platform & the amp is 110 lbs.
If you put a heavy marble slab on top of the cork mat, if it makes you feel better, get the next size up in thickness. Staples has that too but maybe in 12"X12" tiles & not a roll. Since cork is pretty rigid & the surface area of the slab is pretty large the cork should not compress under the slab or components. So, I'm thinking that a 3mm thick cork mat will be fine.
The idea is to damp the marble. I believe that thickness is secondary as even a 3mm mat has sufficient damping capacity from my experience.
The good thing about cork is that it stays the same for a long, long time & does not stick to the surface. Dynamat is also a great mat but ensure that heat & humidity cycles don't make is stick to the surface(s) or disintegrate over time.
For me it really works well.
In fact, when I had a Music Hall MMF5 TT, I threw out the felt mat & replaced it with a cork mat. Much better performance from the get go & no static on the LPs.....
BW, where did you purchase the cork platter matt. Thanks for the additional info about the thickness of the cork board. The downside of placing the cork board under the marble is I would have to very carefully lift the marble slab which weighs alot to position the cork material. Should it fall or slip on my foot or feet I will never walk on them again. Will tell everyone how the slab worked out, still evaluating. Thanks, Jim
BW, where did you purchase the cork platter matt.I made it myself. Bought the cork roll from Staples, put the MMF5 felt mat on it & traced out a circle, cut it out with an Xacto knife, made a spindle hole also with the Xacto knife & I had a cork mat ready to go....
The downside of placing the cork board under the marble is I would have to very carefully lift the marble slab which weighs alot to position the cork material.maybe I am misunderstanding this - you place the cork mat first & then put the slab of marble over it (2-man lift on the marble slab). You don't lift the slab with one had & shove the cork mat under it. Yeah, that's asking for trouble!
06-28-13: Sunnyjimfair enough. The only thing I can say here is that do NOT make a judgement until you have tried the marble slab with the cork sheet under it. Thanks.
Great I think, the heavier the better. I used Marble under my tube amps when I had them as I felt they looked better in the room. I now use granite slabs under all of my equipment. All the source equipment is in a closet but the amps now.
If you do not use some kind of rubber or a mix of cork and rubber most any stone item will ring.
You can buy rubber and cork squares from Mapleshade for way too much money IMO, or you can purchase them on Amazon. They are larger but you can cut them down. They are rated for 50 lbs. per square inch so take all the weight in account. You can use any extras for under equipment.
BTW I sold the Marble with the amps.
To those who responded: Though final conclusions have not been reached, Operation Marble Slab has been generally successful producing benefits in midrange clarity, some increase in bass, and overall, a more coherent presentation of the music. However, nothing was startlingly different.
The following music was used: "E Power Biggs Plays Bach" David Bowie's "Ziggy Stardust"; Steely Dan "Can't buy a Thrill" and one Belle and Sebastian's track titled Lazy Line Painter Jane...hard to believe a calliope would be converted into a powerful rock instrument; Lastly, Mott the Hoople's LP titled "Mott" particularly the last two tracks side 2: "I am a Cadillac" and I Wish I was Your Mother"
One anomaly: On some music there seemed to be less slam and dynamics, mostly on LP's I have heard deeper pedal notes on the Bach LP which was gifted to me 37 years ago. On the Mott the Hoople LP, there are two mandolins that drive the tune. "I wish I was your Mother"; they had less sparkle at the top of their range from what I can recall from before. The CD playback seems to have reaped the most sonic benefits from the marble slab.
Finally, though I cannot quantify it, I felt that I could hear or at least identify the weaknesses of CERTAIN COMPONENTS, AND CABLES. Mainly, the Red Dragon monoblocks amps which overall are very neutral, but have below average lower bass and resolution. In addition, the Morrow MA-3 IC which connects a Musical Surrounding Phenomena II phono stage to the Rega P3-24 crowned with a Dynavector 10X5 spike. MA-3 just did not cut it Transient response on some LP's sounded slow. OK,I know this is a subjective impression; it is probably because I have NEVER liked it to begin AND WAS NON-RETURNABLE BECAUSE OF BEING USED.
The other weak link is the Audio Art SC-5 standard speaker cable which is good, but not the best wire for the AZ Adagios wide frequency response....that is why I keep looking for and asking about better speaker cables in various threads.... SO THAT IS IT FOR NOW!! I will try the cork and/or rubber matting as recommended by BW, and Hevacl. Thanks again to all. Jim
Most Vibration pads are 3/4" thick if it has cork. you can get them made of just rubber much thinner. I would recommend these is you need thinner. Remember you must add more for weight as they are 3.8 thick. here is a link for Amazon http://www.amazon.com/Mason-R18X18MSW-Natural-Vibration-Isolation/dp/B006W0P6Q0/ref=sr_1_11?s=industrial&ie=UTF8&qid=1372678548&sr=1-11
Hevacl. I am considering about 8 of the 3/4 inch blocks would sufficiently carry the weight. The slab is 42 inches L by 20 wide. Nonoise provided a link to a distributor that sells a variety sizes and thicknesses of these rubber cork blocks. They are relatively inexpensive. Check out the link from Nonoise Thanks
I suspect one will have much better results using slabs of marble, granite, etc. if he mounts the slab on cones and avoids the use of soft pliant materials like rubber and cork as those materials impede the rapid evacuation of energy out of the system. Damping the slab is better executed with Mpingo discs or similar devices that off load energy rapidly. When we try to Deaden vibration we often wind up trapping it instead. Tried and true mass-on-spring isolating devices usually improve upon such mundane devices as slabs of marble or granite on cones.
I am in the HVAC/Lab equipment field an have access to all kinds of vibration elimination products directly from supply houses and manufactures. I tried all kinds of things to isolate my system from vibration.
The best thing I did was build a closet to hold my source equipment. It is on the other side of one of the main carrying beams of my house. Only my speakers and amps are in the listening room. I can bounce a basketball in the room while playing a record with no ill effects.
I use SS amps now and do use pads and slabs from Zoethecus that were used for my source equipment before I built the closet.
You can see most of my system in my pictures here on audiogon. The system has changed some as I seem to NEVER stop upgrading this endless hobby.
Okay, fine. I'll answer my own question. This topic has come up before and I mentioned I use soft fiber scratch pads under the feet of the gear. About 2.5 in. squares. Virtually nothing gets transferred through them so exotic platforms are not necessary. I was interested in learning about other decoupling methods as Geoff mentioned. I think mine beat the springs, though.
Has anyone tried neodymium magnets?
I built a mag lev system using neodymium magnets about 20 years ago. Since the opposing magnets have a strong proclivity to slide horizontally, it is an engineering challenge to prevent a path that vibration can travel up through from developing. Nevertheless...
Apologies for the use of three consecutive adverbs.
The ones I buy come from a place called Princess Auto here in Canada. They come in 4x6in. pieces. I use them under my 40lb. TNT200 amps. The amp sits on a veneered piece of particle board suitable for the amp's dimension with full size pad under each corner of the board, down on the carpeted floor. The pads are 3/4" thick. They compress about half way under the weight. For the lighter gear I just cut smaller pieces under their feet and they sit on a shelf on the TV stand. All I can say is there's no lack of detail or extension with them. There is no other materials infused into them such as cleaning agents or abrasives. They are white in color.
Don't know what a post-em is.
Just bought a 2" thick maple wood butcher block for my VPI Classic. Also bought 5 rubberized cork feet. I plan to set the butcher block on the cork feet. I'll report back when all the stuff is delivered.
Hopefully I'll able to kill the bass rumble picked up by the IKEA cheapo table on which I set up the Classic. The IKEA table acts like a sound trap that catches and transmits the bass rumble straight to the Classic and then the cartridge which in turn creates a bass resonance.
Total cost: $160.
I agree but with having limited space of a 1/2" spring isolation is either very expensive or not possible. There is also the WAF factor as make springs look nice without restriction of the spring is a hole different ball game."
I assume that space restriction doesn't apply to the component on top of the rack. I'm not very high on racks, have you considered mounting the components directly on the floor. I can appreciate WAF can sometimes override sonic considerations.
The more I look at it, the more those three consecutive adverbs seem appropriate. :-)
Does anyone know if maple is that much harder than bamboo? I've sourced some relatively inexpensive John Boos maple butcher block cutting boards which happen to be the exact size I need (12"X 18").
All the best,