tuga
Legal Alien
Why is granite good and marble no good?
Granite Boards for Isolation?
- Thread starter Lee T
- Start date
Why is granite good and marble no good?
Sue Pertwee-Tyr
Accuphase all the way down
Not a fan of adding mass, it tends to mess up the bass and the dynamics, IME. If the OP wants to change shelf material, I’d suggest investigating bamboo. IKEA do some cheap chopping boards that would be a good way to experiment at little cost.
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NickofWimbledon
pfm Member
i suspect a really thick piece of marble, far too massive to have any resonant frequencies close to the audible range, could be fine.
My understanding is weak, but the difference seems to have little to do with density in isolation, and may be connected more to crystal size.
In my amateur experiments, we found a sheet of glass and Naim cups and balls were literally the worst thing we tried, but rubbery feet with glass were nearly as bad for sibilance and tinny/ splash treble - harmonica and female voice were worst affected. Whether we are biased by looking at the glass ( I could not properly blind listeners to every change) or r not, the glass did seem to be ringing.
A marble chopping block sounded to us like the glass, not like wood or granite.
i was interested to find that 2 very different professionals (Stephen at The Audio Consultants and LP12-baseboard-maker SRM) without prompting volunteered that glass and marble would sound exactly as bad under the LP12 as we found them to sound.
We tried things under and over Superline phono stage, preamp and CD player too. If on my granite shelves, rubbery feet were good, a wooden chopping board was just about regarded as better than not, and glass and marble were not good. However, on my old Sound Org table, we thought wood worked fine and the metal frame was at least as much of a problem as whether or not the MDF shelves had a wood or stone on them. On that, the cups and balls and added glass were ok but a wooden chopping block from (iirc) IKEA won. Putting things on my wooden floor suggested granite or paving slabs were comparably good and all else less good or actively bad.
Given the results of our trials in just one room, I think generalisations may be the problem. The best way of checking what works well for any room is still not modelling it but listening to it.
Good luck.
NickofWimbledon
pfm Member
We found that too.
Weight can help by damping actual noise from the box vibrating audibly - if you play LOUD, this seemed to apply to my old olive Naim boxes a bit.
Microphony matters too, so big transformers vibrating is not great. Some (like HRS) sell chunks of metal to put on the relevant boxes, and we found those to work better than bricks, books or chopping boards. However, apart from a few things that really didn’t work, all these effects were small if that basic support is any good at all.
Absolutely.
Check the photo out at the top of this link
Avondale Audio Arcam Alpha 5 [English] (tnt-audio.com)
I have four equipment racks with 600 x 600 granite slabs on top of each for mono block valve power, valve preamp, turntable and cd player. They provide isolation free from vibration and weight without deadening sound.
They are an attractive colour and add a luxury look to my system.
They are an attractive colour and add a luxury look to my system.
Sue Pertwee-Tyr
Accuphase all the way down
The problem with adding mass, IMHO, is that most of the energy in a musical signal is in the low frequency range. And broadly speaking, the higher the mass, the more resonant it will be at lower frequencies. So it's more likely to respond to low frequency energy and will absorb it, then re-radiate it after a finite time delay. This messes with the timing of the signal, because the microphony of the equipment is being energised out of time with the musical signal. It's the same argument that speaker manufacturers like Russell K, and the BBC designs, use to explain their choice of undamped, or thin wall enclosures.
NickofWimbledon
pfm Member
This is certainly an important point. Some amounts of some materials transmit different frequencies better or worse compared to bigger/ smaller bits or different materials. The total amount of vibrating that can readily be induced in (say) a 500kg lump of concrete may be so small that it can be ignored at any frequency, but there is no reason to assume that that also applies to 5-10kg, and if the mass and material picked have a resonance in the audible range it seems very likely to be less than ideal. Try it and listen is the only reliable approach imho.
Your point on speakers is well made. Several speakers that don't aim for lots of volume and deep bass are thin-walled and light. Moreover, Dick Shahinian (a musician) argued that damping out all movement was impossible and that attempts in that direction were often the choice of lazy speaker designers - to him, a concrete speaker made no more sense than a concrete violin.
The test here is surely simple. As generation of LS3/5A owners attest, they work well. So do Shahinians, including some that are far from small - I own a set today and am familiar with a couple of others. However, the same ears that tell me how well these work also tell me that plenty of speakers with heavily damped and/ or massive cabinets also work well if designed well. As with most discussions of this sort that point to a nice & simple answer, it is always fair to add the Goldacre rider 'It's a bit more complicated than that'.
A slice of granite rock.
[/quote]or kustone base, just from experience both improve bass on a floorstander....[/QUOTE]
A composite made from resin and ground up rock pieces.
I made two of Xanthe's isolation devices for my Naim NAC62 and NAP140 and they work great.
See https://community.naimaudio.com/t/vibration-isolation-support-for-glass/5955 on the Naim Forum
One large slate base under both boxes.
Then three plumbers brass stop ends and three 7mm silicon nitride ball bearings and a glazed wall tile (upside down) on top of the slate for each box.
The principal is acoustic reflection by using dis-similar materials. The link explains it in detail.
Was initially rather sceptical but surprised how much more coherent everything sounded.
Think it was mainly isolating the mains transformer in the NAP from the NAC which is the most sensitive part of the chain.
Tried one under my DAC but made no difference. Ditto LP12.
Xanthe recommended tempered glass but I just used glazed wall tiles which were much cheaper and initially as an experiment.
No plan to replace them with glass, although glass would undoubtedly look better.
I put black tape round the edges of the tiles to hide the portion visible around the boxes.
The slate was just to provide a level surface as the unit I use is built in and warped slightly. Don't think it makes any difference to the effect.
See https://community.naimaudio.com/t/vibration-isolation-support-for-glass/5955 on the Naim Forum
One large slate base under both boxes.
Then three plumbers brass stop ends and three 7mm silicon nitride ball bearings and a glazed wall tile (upside down) on top of the slate for each box.
The principal is acoustic reflection by using dis-similar materials. The link explains it in detail.
Was initially rather sceptical but surprised how much more coherent everything sounded.
Think it was mainly isolating the mains transformer in the NAP from the NAC which is the most sensitive part of the chain.
Tried one under my DAC but made no difference. Ditto LP12.
Xanthe recommended tempered glass but I just used glazed wall tiles which were much cheaper and initially as an experiment.
No plan to replace them with glass, although glass would undoubtedly look better.
I put black tape round the edges of the tiles to hide the portion visible around the boxes.
The slate was just to provide a level surface as the unit I use is built in and warped slightly. Don't think it makes any difference to the effect.
poco a poco
I'm Jim
Possibly suits high mass turntables more than actives. I use two sheets of 1/2” marble, one on top of the other, the same size as my Lack table top under my Trio L-07D turntable. The table sits on a solid floor, covered by wood blocks and carpet. I also have two sheets of laminate floor underlay under each sheet of marble. I experimented with various combinations of materials, but this was the best and gave a worthwhile improvement IMO. It sounded better than when I had my turntable on a massive wall mounted shelf, but that was in a different house. My LP12 that I previously owned was much worst on that shelf. It was much better on a metal framed table.
For your kit, and your room, there will be something that works best. What works elsewhere may well be different. It's experiment time.