[TheChairGuy]

Duplicate post from something I posted over at VinylEngine...but, worth exposing vinylphool's here to it, too.
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I've extolled the virtues of this stuff before (as have others), but I don't think I ever devoted a solitary post to it previously.

The list of tools in the tweekers arsenal are long...but, this one is extraordinarily cheap, effective, reversible and excellent.

I've seen folks recommend them inside turntable hollow bodies...but, I've always found modeling clay to be more effective. It may only be that the added weight of the clay adds some mass damping that helps sonics over and above what constrained layer stuff does.

Beats me I just call 'em as I regularly hear 'em.

I've made 12" round platter mats with various types. ALL have been preferred to rubber mats....and they certainly damp metal platters well...they don't seem to provide an IDEAL interface with records. I prefer various silicone ones fashioned, but the best has been Herbie's mat (which is, not coincidentally, silicone based)

Where constrained layer damping comes in as your best buddy is on your tonearm. Set a dot on the headshell top, one on the arm over the pivot point, sometimes one on the counterweight...and sometimes one other at some point along the arm itself. Finally, two or three on the armboard is normally helpful, too.

The only way to hear it's effects are thru hearing. You'll pretty much know when it sounds overdamped....the bass and transients will sound truncated (end too early, unnaturally so). I use piano to tune to taste...it's the largest instrument with the greatest range - so it's the most difficult instrument to get to sound just right. Perhaps you have another fave - use whatever you like - this is only what I works best for me.

The pronounced betterment of many tonearms will leave you scratching your head how $0.50 of damping material could improve things so much

I use EAR Isodamp (who supplies such damping compounds to the US military, among others). There are other suppliers, as well.

Here's how they can be applied...http://www.musicdirect.com/product/73864 but, you need not spend USD$49 to achieve the same effectiveness (large sheets are usually $10 and you can make 500 of your own dots...enough for 50-80 tonearms).

However, the $49 spent will likely be revelatory - bettering most cartridge or tonearm 'upgrades' for similar money spent (bettered only by the lesser cost of $10 and doing it yourself for savings)

Enjoy, John

[Speedskater]

Why in the world do they call it "Constrained Layer Damping" ???

[TheChairGuy]

Why in the world do they call it "Constrained Layer Damping" ???

It looks pretty much like a sandwich.  A thin piece of aluminum (sometimes stainless steel) is sandwich by two pieces of rubber or bitumen.  Sometimes it's the other way around - the rubber is sandwiched by strips of aluminum or stainless (there may well be other materials used I am not aware of)

The idea of it is that a layer is 'constrained'.  When this sandwiched materials is applied to something....it 'damps' the energy/resonance and turns it into harmless heat. 

One cannot get rid of resonance, excess energy, you merely turn it into something else.  In this case the else is heat.

There's probably sources on the net with much better or more complicated explanations of it (and someone here may be better versed in it), but that's it in something of a nutshell.

Whatever the reason and whatever the makeup.....it works on tonearms.  You just need to let your ears tell you when enough of it is enough

John

[TheChairGuy]

Source: SoundDeadSteel

This is what constrained layer damping looks like:

[Speedskater]

Now how do the two above correct descriptions of CLD apply to these little dots???

[TheChairGuy]

Now how do the two above correct descriptions of CLD apply to these little dots???

I've made small bits (under 1/4" square) of CLD.  They can be cut with scissors or hole punches to make 'dots'.  They work on tonearms best...just a little will do

Each tonearm will take to it differently, the materials and thickness themselves will skew results, as will one's personal bias on what the sound of what 'overdamped' means to you....but use of CLD (or EAR Composites as I have now) are welcome on every tonearm tried (from stock arms on cheap direct drives to an Origin Live Illustrious Mk. II...a $2800 arm)

If you have not tried it - you're likely in for a very nice $10 treat (the cost of a typical 8 x 10" entire sheet of thin CLD material)

Regards, John

[Letitroll98]

.............Where constrained layer damping comes in as your best buddy is on your tonearm. Set a dot on the headshell top, one on the arm over the pivot point, sometimes one on the counterweight...and sometimes one other at some point along the arm itself. Finally, two or three on the armboard is normally helpful, too.

I'll second this one, and add one later.  I could not run Empires and Grados on an RB300 without these little dots.  One or two on the arm itself, two on the counter weight, and one on the end of the stub.  You can make them yourself for pennies with a hole punch out of a sheet of the 3M damping sheets.  You have to experiment with the number and placement, but it's quite evident when you have too many as the sound just dies, just take a couple off and the dynamics return without the overhang.

My second recommendation is for under turntables.  I use 2 MDF shelving pieces with a styrofoam building sheet in between as the damping layer.  I'm sure there are better combinations of materials, but I haven't got round to trying them.  In any case, a CDL is much better than a cutting board or maple block for damping table resonances and much cheaper than most wooden blocks of a large enough size to work on a full size table.         

[Wayner]

Adding plasticlay to the innards of a TT actually changes it's resonance frequency by lowering it. This usually puts those low annoying frequencies out of the human hearing range. The added mass does the magic.

CLD on a tonearm is kind of the same thing, All things have a resonance frequency, and so do tonearms. If the tonearm isn't designed to handle some of these, or the combination of a particular cartridge and tonearm are assembled, the combination may actually double the intensity as the combination of arm and tonearm, loved the same resonance frequency and started a harmonic loop, if you will. The bad side affect of this is other order sympathetic frequencies that want to join in with the party. At some point, the energy created during tracking will be enough to disturb the cartridge's tracking and muddies the sound. Responsible CLD placenment can act like a "graphic equalizer" in the mechanical mode, reducing the resonant energy of the offending frequencies. Too, much CLD treatment and the energy meant for the stylus is robbed, incorrect placement and other frequencies may be affected, putting different dips into the overall frequency response of the entire TT system.

Wayner

[dmatt]

I'm not sure how accurate the following article is (I will leave that up to the Mech E.s on the site), but it certainly broke the concept of constrained layer damping down into chunks I could understand.  Worth the quick read.

http://www.sciencebuddies.org/science-fair-projects/project_ideas/ApMech_p040.shtml

Oh, where was the internet when I was a kid.  All we had was Dr. Science and Mr. Wizard.

David

[analognut]

TheChairGuy said:

"One cannot get rid of resonance, excess energy, you merely turn it into something else.  In this case the else is heat."

To me this is incredible, it sounds like something a physicist would say, and it's very true. I recently learned of this fact while viewing The History Channel's "The Universe" on TV. Energy is eternal and indestructible. It merely changes its form. In this instance we are turning tonearm resonance energy into heat. Remarkable! 

[Wayner]

I believe it was Albert Einstein (or some other smart dude) that made that comment that energy cannot be created or destroyed, only changed in form. Matter cannot be destroyed either. We can split the atom, but the sub-atomic particles will find a new home.

Wayner

[TheChairGuy]

To me this is incredible, it sounds like something a physicist would say, and it's very true. I recently learned of this fact while viewing The History Channel's "The Universe" on TV. Energy is eternal and indestructible. It merely changes its form. In this instance we are turning tonearm resonance energy into heat. Remarkable! 

Yeah, it is pretty cool to think about.

But, I'm about the furthest thing from a Physicist one could think of...so it makes me even doubt the validity of the statement that I wrote

EVERYTHING in the universe is, stores or exhibits some kind of energy. It is never destroyed or absorbed, merely deflected into another form of energy.  That's truly freakish' and connects all of us to all things on this earth and in the universe just a little bit more demonstratively

John

[analognut]

Wayner-
Actually, if by "matter" you mean atoms or molecules, then matter is another guise that energy takes. Matter traveling at the speed of light squared, that is. (e=mcc). All this thinking is too much for me, I need to watch some TV to relax.

First though, since I have an opportunity here, I want to complain about the "4 basic forces of nature" that physicists talk about. Those being Gravity, Electromagnetisn, and the Strong and Weak Nuclear Forces. They talk like they know these things, but they actually know diddly, if that much. For convenience let's assume they may be correct about 4 forces, but it's obvious to me there are at least 5, and we won't fully understand anything until we get this part right! IMHO the power of the MIND would be number 5. This would include all of the paranormal abilities that some people have been shown to exhibit, such as telekinesis, the ability to leave your body with your mind, and many others, for example. IMHO science will need to include the metaphysical plane before we can truly understand anything. And if you believe in number 5 it gets you to wondering if there might actually be 1 primal force and everything that we observe is a manifestation of the 1.

[neobop]

I believe it was Albert Einstein (or some other smart dude) that made that comment that energy cannot be created or destroyed, only changed in form. Matter cannot be destroyed either. We can split the atom, but the sub-atomic particles will find a new home.

Wayner

Back to the physics - It was Einstein in 1905 who theorized that energy and matter are equivalent. E=MC2.
http://en.wikipedia.org/wiki/Mass%E2%80%93energy_equivalence

I think the laws of conservation of energy predate that.

We generally think of the world as having 3 dimensions. Time is often thought of as a 4th. If we encountered a creature who functioned in 2 dimensions, we could reach into that world and manipulate things with our superior dimensionality.

Physicists think there may be as many as 11 or 12 dimensions. We can plot a 4th physical dimension (excluding time), but that's about it. I think that's the reason we'll never get very far with space travel with our present understanding of the universe. Perhaps the Creator is a being, beyond our comprehension, who functions in all dimensions. Timeless, as it were.
neo

[neobop]

I bring up the concept of dimensions because it has everything to do with the analysis of a record player. If we didn't already have records and players, and someone suggested it, it would probably never be built. The whole thing seems impossible. Consider this:

The stylus, tracking a groove, tracks in 3 dimensions. Side to side, up and down, and angular, just like our 3 dimensional world. Grooves are cut at 45 degrees. This all happens in real time. [I agree with Einstein that time can be considered a 4th dimension.] I've read that this can be called the sphere of tracking. To complicate matters more, there are quite a few other aspects
of tracking analysis. But how exactly, we get stereo from 1 stylus tracking both sides of a groove at the same time, is mind boggling. If I didn't already know, I would guess that it wouldn't work.

Some of the other forces or vectors that effect record playing are the rotation of the record, and arm movement towards the spindle. The sphere of tracking is constantly moving, not just inward, but back and forth (& up and down) cause most record grooves are at least slightly off center. So, we have 3 dimensional tracking within the sphere, and the whole sphere is also moving in 3 dimensions. Whether the inward movement is another dimension or a force vector, is debatable. The sphere of tracking simulates our solar system travelling through our spiral galaxy. Only the net progress is outward in the galaxy, not inward - expanding universe?

Be that as it may, more mundane considerations like stylus drag and skating with pivoting arms are also to be considered.  What's this have to do with CLD, you might ask. Err..... Good question. All damping, is reducing the amplitude of physical vibrations or electrical oscillations. Like getting a nice smooth ride from our milky way travelling through the universe. 
neo

[Letitroll98]

TheChairGuy said:

"One cannot get rid of resonance, excess energy, you merely turn it into something else.  In this case the else is heat."

To me this is incredible, it sounds like something a physicist would say, and it's very true. I recently learned of this fact while viewing The History Channel's "The Universe" on TV. Energy is eternal and indestructible. It merely changes its form. In this instance we are turning tonearm resonance energy into heat. Remarkable! 

This is the First Law of Thermodynamics and yes neo, it does predate Einstein's Special Theory of Relativity.  The four Laws of Thermodynamics are fundamental to Relativity, but Einstein was really just trying to work out some inequalities in Maxwell's equations and Relativity, both Special and the later General Theory which includes gravity, were the result.  Notably, Einstein received the Nobel prize for a different one of his three groundbreaking papers released in 1905, not Special Relativity.  The other two were one that started Quantum Physics and the one he won the prize for, a paper on Brownian Motion.  But I digress.

Anyway, the first law states that energy can neither be created or destroyed, it can only change form.  And that with any process in a closed system, the total energy remains the same.  The Second Law of Thermodynamics is related and states that entropy must always increase.  I'd have to explain the Zeroth law and how it relates to the other laws to fully explain it, but that's the jist of it, chaos comes out of order, not the other way around as Nietzsche said.  So to dissipate the excess vibrational (or resonant) energy in a tonearm it has to be changed to something, in this case it's heat.  It's the CDL that does the converting.   

Matter cannot be destroyed either. We can split the atom, but the sub-atomic particles will find a new home.

Yes Wayne, matter can be "destroyed" by converting it into energy.  About 0.04% of matter is converted into energy in a fusion reaction (atomic bomb), much less than you would think.  When matter encounters anti-matter, nearly all of it is "destroyed" or converted into energy.  It's energy that cannot be destroyed, but since matter is just another form of energy and doesn't really exist except as a temporal object (it doesn't actually have a position until observed) you are essentially saying the same thing when you say "matter" cannot be destroyed, but in a different way than you previously imagined. 

[*Scotty*]

Here two links to 3M constrained layer damping sheets.
I used these on my phono cartridge and tonearm to good effect.
http://www.musicdirect.com/product/72701
http://www.musicdirect.com/product/72703
Scotty