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Looking for experience in damping material

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Posted on March 1, 2013 at 12:51:48
Mushroom Soup
Audiophile

Posts: 151
Location: Western New York State
Joined: November 1, 2003
On my first Thorens turntable, decades ago, I damped the subchassis with the deadest material I could fine, which was a roofing shingle. It was damp, all right, but much too heavy for the springs.

I know that some damping materials do more harm than good. Does anyone have a take on a material that does its damping chores reasonably well, doesn't weigh a ton, and makes the sound better rather than deader?

Thank you kindly

Mush

 

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RE: Looking for experience in damping material, posted on March 1, 2013 at 19:46:11
Bill Way
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Location: Toms River NJ
Joined: May 28, 2012
Contributor
  Since:
December 14, 2012
For my TD125 I made an arm board of a plexi-lead-plexi sandwich, epoxied together. I think the lead was 1/8" or so. Very easy to make: you can cut the lead with big snips, and the plexi is easy to cut and trim (use a small rasp plane to smooth the cut edges.) I think I got the materials on ebay. Merrill used to make an add-on lead platter mat, which I epoxied to the outer platter after making a jig to get it centered. I replaced the springs with 1"(?) sorbothane spheres, which made a huge improvement in imaging, at the cost of less feedback isolation, so I spiked the whole thing. (The spheres get better after a few years as the sorbothane squashes more and gets a little firmer.)

I haven't opened it up in ages, but seem to remember cutting a few lead sheet pieces to glue to the subchassis cast aluminum parts.

WW
"A man need merely light the filaments of his receiving set and the world's greatest artists will perform for him." Alfred N. Goldsmith, RCA, 1922

 

WOW!, posted on March 1, 2013 at 21:07:14
unclestu
Dealer

Posts: 5851
Joined: April 13, 2010
nice work and a lot of it or so it seems. Nice website too

Stu

 

RE: Looking for experience in damping material, posted on March 4, 2013 at 09:41:16
Mushroom Soup
Audiophile

Posts: 151
Location: Western New York State
Joined: November 1, 2003
Huh. I've got some lead like that -- I got it to put under the bridges on electric basses. It would be a bit thick for this application, though. Maybe I'll go look for some 16ga or so.

 

RE: Looking for experience in damping material, posted on March 4, 2013 at 15:59:28
6bq5
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Posts: 2114
Location: SF Bay
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September 14, 2012
It is often sold for Roof flashing - and is reasonable to work with...
Happy dampening
Happy Listening

 

RE: Looking for experience in damping material, posted on March 4, 2013 at 22:27:38
Mushroom Soup
Audiophile

Posts: 151
Location: Western New York State
Joined: November 1, 2003
Very cool, thank you.

 

RE: Looking for experience in damping material, posted on April 9, 2013 at 04:12:18
b.l.zeebub
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Posts: 5120
Location: 52deg 28'N,1deg56'W
Joined: April 17, 2006
If you don't like the idea of working with lead you could try stuff like this:


 

I've used Dynamat before, posted on April 15, 2013 at 15:05:11
E-Stat
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Posts: 23563
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Contributor
  Since:
April 5, 2002
with CD players. Designed for car stereo use, easy to find and has adhesive backing.

 

RE: Looking for experience in damping material, posted on October 16, 2013 at 04:36:10
jrlaudio
Manufacturer

Posts: 44
Location: New York
Joined: November 2, 2012
Sorry but I have to be a noodge.

The phrase is damping. Dampening means to make something wet. Hmmm ... No I won't go there!

 

RE: Dampening, posted on October 16, 2013 at 05:09:49
geoffkait
Manufacturer

Posts: 9321
Location: northern Virginia
Joined: August 23, 2000
According to my sources (the dictionary), dampening has several meanings.

v.tr.
1. To make damp.
2. To deaden, restrain, or depress: "trade moves . . . aimed at dampening protectionist pressures in Congress" (Christian Science Monitor).
3. To soundproof.

 

RE: Looking for experience in damping material, posted on October 16, 2013 at 18:34:46
Inmate51
Audiophile

Posts: 8490
Joined: July 6, 2005
I don't have a specific recommendation for you. What you use depends upon what you're trying to accomplish.

If there are vibrations which are generated internally in your turntable, that's one thing. If you're looking for a more stable and solid base upon which to place your turntable, that's another.

Breaking it down to the nitty gritty, what you're dealing with is a mass/spring resonant system. Reducing unwanted vibrations and troublesome resonances is a well-understood science. Google "vibration control" and you'll have enough stuff to read 'til next year.

Ok, that's all I've got for now. Gotta go make another drink.

:)

 

RE: Dampening, posted on October 17, 2013 at 21:51:39
jrlaudio
Manufacturer

Posts: 44
Location: New York
Joined: November 2, 2012
None those definitions have anything to with reducing mechanical vibration; in mechanics it is damping.

However, in acoustics you can provide dampening of sound waves traveling through air.

So for example ... if you do not provide adequate damping of vibrations in your machine, you may have to provide some type of acoustical dampening to eliminate the sound produced.

They are related but different phenomenon with different nomenclature.

It's kind of like the different terms effect and affect.

Where as ... if you do nothing to mitigate the effect of alcohol, you may feel like your judgement is affected.

I remain ... the noodge! :-)

 

RE: Dampening, posted on October 18, 2013 at 06:54:17
geoffkait
Manufacturer

Posts: 9321
Location: northern Virginia
Joined: August 23, 2000
You wrote,

"None those definitions have anything to with reducing mechanical vibration; in mechanics it is damping."

You also wrote,

"However, in acoustics you can provide dampening of sound waves traveling through air."

Acoustic waves ARE mechanical waves. Hel-loo!

:-)

 

RE: Dampening, posted on October 20, 2013 at 22:28:18
jrlaudio
Manufacturer

Posts: 44
Location: New York
Joined: November 2, 2012
No they are not the same as you infer. They are very different. And I didn't refer to mechanical vibration as waves. However I will now in terms of properties.

Mechanical vibration can be transduced into acoustic waves and visa-versa.

Mechanical vibration can exist in a vacuum where acoustic waves cannot. The classic example of a bell ringing in a vacuum chamber; the bell vibrates mechanically, but there is no transduction into acoustics waves since there is no air.

Mechanical vibration is mostly expressed as transverse waves, sometimes surface waves and sometimes longitudinal waves.

Acoustic waves are exclusively pressure waves and are almost always longitudinal waves.

Again, the reduction of energy of mechanical vibration is damping.
The reduction of energy in acoustic waves is dampening.

Two different terms for two different types of energy state changes.

By the way, reduction of energy in an electromagnetic wave is called loss.

All of these energy transfer modes and the reduction of energy in each can be referred to under the broader term, attenuation.

So feel free to use attenuation, it's much less specific or apparently less problematic. :-)

 

Earth to jrlaudio, posted on October 21, 2013 at 05:16:51
geoffkait
Manufacturer

Posts: 9321
Location: northern Virginia
Joined: August 23, 2000
If dampening is ok for acoustic waves it's ok for mechanical vibration. They're both mechanical. Don't get so hung up on semantics. Remember, it's only a hobby.

Cheers

 

RE: Looking for experience in damping material, posted on October 28, 2013 at 13:33:40
Tweaker456
Audiophile

Posts: 2080
Location: No. Cal
Joined: January 19, 2012
EAR C-1002 is the finest damping material on the planet, IMHO. Thelowly rope caulk is also great, easy cheap, easy to take off if you don't like it. Tweaker
"Freedom is irrelevant. Self-determination is irrelevant. You must comply." The Borg

 

EAR blue stuff, posted on October 29, 2013 at 07:02:57
geoffkait
Manufacturer

Posts: 9321
Location: northern Virginia
Joined: August 23, 2000
Once upon a time when I was casting around for damping materials for certain applications I obtained a bunch of EAR blue feet of various sizes, grommets, and damping sheets. While these pretty blue things seems like SUCH a good idea, especially the semi hard EAR feet and grommets I was hoping to use in the construction of a very low resonant frequency isolation stand, I found these EAR thingamabobs reduced dynamics and softened and homogenized the sound. Gave them all to Goodwill. Sometimes trying to cross pollinate industrial products, like Sorbothane, to high end audio just doesn't quite work out. Whether it be thermoplastics, viscoelastic polymers, or other cool-sounding material what frequently occurs is a bad case of "over dumping" as Acoustic Revive is fond of calling it.

 

RE: Looking for experience in damping material, posted on May 18, 2014 at 11:08:16
Mushroom Soup
Audiophile

Posts: 151
Location: Western New York State
Joined: November 1, 2003
I nominate this for the Most Egregious Nonanswers award for this year

 

RE: Looking for experience in damping material, posted on June 17, 2014 at 10:23:27
Palustris
Audiophile

Posts: 1840
Location: Cape Cod
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"I nominate this for the Most Egregious Nonanswers award for this year"

I agree: he thought you wanted to understand the problem and all you wanted was a simplistic answer.

 

RE: Looking for experience in damping material, posted on July 7, 2014 at 12:14:40
pictureguy
Audiophile

Posts: 6885
Location: SoCal
Joined: October 19, 2008
Too bad there IS NO simplistic answer.
Understanding the problems involved in reaching whatever the desired goal is would be the first thing on the 'list'.

For me to suggest say, dynamat, and not know the goal wouldn't serve the OP well.

Here is a fairly simple article from the AUTOMOTIVE view. Some problems similar to the OP goal may be part of this article.


Too much is never enough

 

RE: Looking for experience in damping material, posted on August 15, 2015 at 03:25:44
stevenmbell
Audiophile

Posts: 85
Location: Scottville, Michigan
Joined: March 11, 2009
I haven't made anything wet in years.So I'll stick to Damping.Come to think of it I haven't done much in years.

 

RE: Looking for experience in damping material, posted on August 18, 2015 at 14:36:50
6bq5
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Posts: 2114
Location: SF Bay
Joined: August 16, 2001
Contributor
  Since:
September 14, 2012
I just aquired an Empire- not sure which- but in searching the archives I came across the following link where they talk about brass filings in a ploymer...
Very interesting- and may well work for you!
Happy Listening

 

RE: Looking for experience in damping material, posted on August 22, 2015 at 01:23:12
pictureguy
Audiophile

Posts: 6885
Location: SoCal
Joined: October 19, 2008
It is an ENGINEERED solution but follow along.
Lets say you have 2 'things' each of which ring like a bell when tapped or struck.
You'd say to 'damp the heck out of it' and the vibrations will 'go away'.

Well, another approach exists.

IF the frequencies of resonance are arranged JUST SO, the 2 vibrating pieces will actually cancel one another out and produce a fairly inert structure.

My Long Gone Dual 1219 TT had a 2 piece platter. EACH piece individually resonanted when struck. Bolt 'em together? Very inert. The resonant frequency was dropped to a VERY low value and at a low amplitude, given input energy limits. Worked well.
Too much is never enough

 

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