Damping Platter With Liquid Latex

[cats squirrel]

no, Eoin, the undamped mug is on the right (in the red trace) and the one on the left is with 175g of 'catodamp5' applied, about £1.70's worth of material.

If you want to reduce the vibrations getting to the platter, then damp the other parts of the deck, or replace those parts with materials that are intrinsically damped, which is far more effective. Then a tiny bit of damping material on the platter, just to take the edge off the ringing, et voila, music!

[Ldg]

Er, is this a commercial product, CS ...........???

[cats squirrel]

ld,

sometimes its takes time to build to the highest amplitudes, I have noticed this many times, and other times different frequencies are more prominent as damping is dependent on frequency.

Yes, the mug in any guise is underdamped, all simple structures are underdamped (less than critical). For a critically damped structure, the damping factor value would be 2.00, the highest I have measured is approaching 0.9, so all the single materials (including composites) that I have measured are nowhere near critically damped.

Unless one is talking about ringing, then one has to apply damping material where the thing vibrates, this does not mean the object that is vibrating has to be covered, about 50% of its surface will probably be OK. But one cannot reduce all the vibrations by applying a tiny amount to the magic spot. If that were so, we would see a tad of damping applied to platters from manufacturers.

[Ldg]

Is 'catodamp5' a commercial product, CS ?

[Eoin]

The problem with my ariston is that the top deck is made of a light steel plate with the suspension bolts slung underneath so it's not really very stiff or flat and is probably transmittting the motor vib nicely straight into the suspension springs.

Bit of a job however to remake it. A bit of plywood or mdf might work but I'd need to get brutal to remove and replace it and you start to end up with a bit of a 'Trigger's broom' of a deck.

[cats squirrel]

I understand, Eoin, bit of a bummer, anyway to put your mind at rest, and because I want a mug of coffee, I have just recorded a Lenco heavy platter for you. Here you go, I couldn't find a ld 'sweet spot', so ended up putting 500g of 'catodamp5' on it:



the undamped platter rang (left plot) for over 10 seconds, the right hand trace is of the damped platter.

maybe that will put things into context for you. [Moral, get a Lenco!]

ld, the 'catodamp5' is not a product yet, but I have 'frozen' the formulation while I work on others. I may produce it if people are interested and accept my findings!

[Ldg]

ld, the 'catodamp5' is not a product yet, but I have 'frozen' the formulation while I work on others. I may produce it if people are interested and accept my findings!

Well, you can absolutely count me out of any future contribution to your posts on this and related topics, CS

In case it helps, much of the underlying physics is total bunk, and potentially misleading to members here in the grand scheme of things.

I mean really.

Moral : to damp a platter, use a mat.

[cats squirrel]

Luckdog,

I'm sorry you have that attitude, but I've noticed you have had problems with other people on this forum. However, I don't have an issue with you, and if your physics is not the same as mine, we'll have to disagree, I guess.

However, many audiophiles and music lovers, and even some manufacturers of audio equipment have been more than happy with my contributions to their needs.

Importantly, I don't see any contribution from you that has helped this discussion.

[Ldg]

Importantly, I don't see any contribution from you that has helped this discussion.

Likewise, CS. Besides, what I posted on this thread it is clearly a valid contribution. There's only one set of physics, BTW. I'm all in favour of helping people, but not to commercial ends. Sorry chap.

[cats squirrel]

agreed, one physics. (in this universe )

and I haven't asked for any help from you, and you haven't given any.

And all the help I have given has been for free. Ask anyone.


Eoin, you could damp the steel deck plate (with 'Newplast') or use it in a true cld design by adding a viscoelastic filling in a steel plate sandwich. Or you could use mdf between two steel plates, similar to at least one bouncy castle deck plate supplier.

[Ldg]

and I haven't asked for any help from you, and you haven't given any.

And that's why you normalised your last graph plot then...........

[cats squirrel]

I normalized for your benefit, not mine.

When I measure damping factors, I amplify the signal to get as accurate a reading as possible, then measure the peak heights, and do the calculations. The amplified signal is to 1 volt, so one could say it is normalised. But comparing two different signals has no value being normalised, as it all depends on the original amplitudes, therefore the normalising is for visual comparison only, which is of no relevance to me.

[Ldg]

therefore the normalising is for visual comparison only

I see. And the purpose of the plot is for......visual comparison. Look, it is simply the best way to present such things. So long, CS.

[Eoin]

ld, you've got some great scientific and mathematical knowledge here so please continue to contribute. This is a learning forum for me and debate and argument can help.

I think you've got the wrong end of the stick slightly on the normalisation issue though here with respect to damping.

Chaps I want specifically to reduce motor vibrations from propogating through the deck. Cats, I thought I'd understood that your measurements suggest that damping is unlikely to be effective in preventing this. Have I misunderstood? Are you saying a layer of nuplast and a steel sandwich below would work? This is not too hard to make.