Greg Lake: 180 g LPs(or heavier) are unnecessary

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kap'n krunch

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Greg Lake , as one of the last things he did before shuffling off this existence, left us with an interesting observation and an engineer's point of view stating that the more mass a slab of vinyl has, the more unwanted resonance are produced.

It is quite interesting and it does make sense to me.

BTW, the last 3 ELP LPs that were repressed and sold from PledgeMusic are VERY good quality (although they suffer from low volume because so much was crammed on one side (e.g., "Fanfare for a common man" and "Pirates" on one side!!)...
 
Greg Lake , as one of the last things he did before shuffling off this existence, left us with an interesting observation and an engineer's point of view stating that the more mass a slab of vinyl has, the more unwanted resonance are produced.

It is quite interesting and it does make sense to me.

BTW, the last 3 ELP LPs that were repressed and sold from PledgeMusic are VERY good quality (although they suffer from low volume because so much was crammed on one side (e.g., "Fanfare for a common man" and "Pirates" on one side!!)...

Isn't it the opposite... the more mass a slab of vinyl has, the fewer unwanted resonances it produces? And its not just records... its a physical law.
 
well, I ain't no genius (and my grammar ain't that good either ;) )
BUT
AFAIK, sound travels better through solids and water than thru air, so , the more material to resonate from, the more "sustain" it will have .....just "ask my Les Paul" and then "ask my Fender Squier"...wouldn't it be so difficult...my Les Paul has a WICKED sustain!!!!! (play a chord and let it ring and you can go have a coffee , come back and it will still be resonating!)

(I apologize if this subject would "belong" better at THAT other forum)
 
Isn't it the opposite... the more mass a slab of vinyl has, the fewer unwanted resonances it produces? And its not just records... its a physical law.
The vibrations (not only those that resonate) are produced at the stylus/record interface. It would make sense that the more massive the record (and the cartridge body) the more they will dissipate before returning to the S/R interface and affect playback.

So ideally there should be an energy-damping path from the record to the platter and beyond, and a second one from the cartridge body to the tonearm and beyond.
 
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I don't want to start a debate here, because I'm not positive of all this. Its been a long time since my last physics class. I would like someone who is truly in the know to explain all this properly and correct me if I'm wrong.

I thought that...

Sound is a variation in fluid pressure. When you strike two solid objects together it makes them vibrate. The vibration causes the air around those objects to also vibrate causing small compressions (changes in air pressure). What you actually "hear" when you strike the objects is the compression of the airwave when it strikes your ear drum. If you strike the same two objects together in a vacuum no sound is made because there is no air (no fluid) for the wave to travel through. Although there may be some vibration of the solids themselves, there is no medium that can carry that to your ear.

Every solid body has a resonate frequency where the body is so excited it vibrates at a maximum level. The resonate frequency is a function of the size, shape, material properties, and mass of the object.

You can shatter a lightweight glass with a sound wave if you tune the frequency of the wave to match the resonate frequency of the glass. It excites the glass to such an extent that it simply vibrates apart. But to shatter a heavier glass takes a lot more motion and a much louder sound.

With respect to audio applications, speaker stands, turntable stands, etc are often filled with sand to make them heavier in order to damp out resonance. The more mass we add to those items, and the more energy it takes to set them in motion because the energy is spread across all the extra mass. Good turntable platters are heavy for two reasons: to damp out resonances and to provide a flywheel effect (less speed variation). I believe its the same idea behind 180 gram vinyl.

Both air and water are fluids. Sound travels through water faster and farther than air (but not "better", I'm not sure what "better" is). This is because water molecules are closer together than air molecules. But the water molecules are also heavier than air molecules so it takes greater effort to start a sound wave in water because it requires more force to set them in motion.

For all audio applications air is the fluid media. Resonances are caused by a sound waves (air compressions) hitting solid objects in the room and making them vibrate. That vibration hits a maximum when the wave is close to the resonate frequency of the object, but even if its not, smaller resonances will be induced. It you want to reduce the audibility of this you increase the mass of the vibrating object which in turn requires more energy to start it vibrating in the first place.

That's my story and i'm sticking to it until over ruled by a more knowledgeable party.;)
 
The vibrations (not only those that resonate) are produced at the stylus/record interface. It would make sense that the more massive the record (and the cartridge body) the more they will dissipate before returning to the S/R interface and interfere.

So ideally there should be an energy-damping path from the record to the platter and beyond, and a second one from the cartridge body to the tonearm and beyond.

agreed
 
OK, there are two factors here, the width of the slab and the cartridge/stylus resonance.....

The Stylus is not only playing bak the signal , but creating the resonace from the playback...I'd think that the less matter that exists to create those resonances, the less there is to pick up by the stylus...

It's like a venue; the bigger the place, the more echo/reverb you'll get....

And please , don't hold back , feel free to to post your thoughts...I'm open minded and won't reply in a disrespectful way..all of you guys are my bunch...(except for one...beacuse there's ALWAYS an exception- and even then I don't give a shit about him anymore...)

This is getting really interesting...
 
OK, there are two factors here, the width of the slab and the cartridge/stylus resonance.....

The Stylus is not only playing bak the signal , but creating the resonace from the playback...I'd think that the less matter that exists to create those resonances, the less there is to pick up by the stylus...

It's like a venue; the bigger the place, the more echo/reverb you'll get....

And please , don't hold back , feel free to to post your thoughts...I'm open minded and won't reply in a disrespectful way..all of you guys are my bunch...(except for one...beacuse there's ALWAYS an exception- and even then I don't give a shit about him anymore...)

This is getting really interesting...

This is all in terms of the stylus/ record interface... As the stylus traces the grooves it impacts the groove walls of the record. Any impact causes a vibration. The vibration causes sound which you can hear at a very low level with your ear up close to the stylus as it plays, even with all amplification turned off. The vibrations in the stylus are turned into electrical signals in the cartridge body and eventually get amplified. But the record also vibrates due to the impact, and this is undesirable because now we are adding more vibration beyond what is contained in the grooves back to the stylus. And it gets even worse because the timing is off. The impact of the stylus and record surface produces a limited amount of energy so, if we increase the mass of the record (or do something like couple the record to the turntable platter that many systems do by way of a spindle clamp) we get to a point where the energy we introduce to the record is used up just trying to vibrate the extra mass. It never gets to a point where it starts vibrating wildly because there isn't enough energy available to vibrate that much mass. If we lower the mass, the amount of energy produced by the stylus/ record impact stays the same or nearly so, but now it can excite the record to a greater degree because it is lighter. There is the same amount of energy available to excite even less mass. Also as we lighten it, the resonant frequency of the record increases and gets closer to the audible range where it becomes more problematic. A typically good resonance frequency for a cartridge/ tone arm is like 12 hz or less, well below the limit of human audibility. We don't want to hear the effects of the tone arm (or cartridge body, or cantilever, etc.) vibrating, so we design it all to have its peak resonance below the threshold of human audibility where we cant hear it, even when it does happen. The problem is, each resonance also has harmonic frequencies which are above the audibility threshold and can become audible (although they are lower in amplitude). So a 12 Hz resonance may not be audible, but its harmonics that might occur at 24, 48, 96, Hz are. (i'm not sure where the harmonics actually fall but I doubt they are that evenly spaced).

Here is another way to think about it. Lets keep the record mass a constant and start lightening up the cartridge/tone arm assembly. What happens? As the cartridge becomes lighter and lighter you reach a point where the cartridge starts vibrating so wildly it will jump out of the record groove. How do you solve that? You make the cartridge heavier. Typically we just increase the tracking force, which while not exactly the same thing, produces the same result by shifting more mass to the cartridge side of the tone arm. With your idea, we would just make the cartridge lighter and lighter so there would be less mass to vibrate. Do you think it would stay in the groove then?

This isn't the same thing as reverb in a venue. Reverb is sound hitting a surface and bouncing off. It takes sound time to move, so you hear the direct sound and then a microsecond later, you hear the reflected sound. You can also get standing waves where the sound just keeps bouncing across the same surfaces repeatedly (very undesirable). A resonance is that sound hitting a surface and making the surface itself vibrate (the sound hitting a surface is also an "impact" just like in the record groove). So the bigger the hall, the more surfaces there are to reflect off, the more reverb. How do you control that? You hang sound absorbing panels which are made of a material which is not so rigid and cant vibrate as much as a hard surface. They absorb the sound waves into a material that isn't easy to make resonate.
 
I doubt it makes much difference one way or the other. If it made such a big difference, CD-4 records would have a hell of a time stamped as Dynaflex, and they don't.

Doug
 
BTW, the last 3 ELP LPs that were repressed and sold from PledgeMusic are VERY good quality (although they suffer from low volume because so much was crammed on one side (e.g., "Fanfare for a common man" and "Pirates" on one side!!)...

that's how it was on the original LP. Fanfare + Pirates = side 4.
 
I doubt it makes much difference one way or the other. If it made such a big difference, CD-4 records would have a hell of a time stamped as Dynaflex, and they don't.

Doug

I do agree with that... I was only pointing out the theoretical ideas behind using the higher mass vinyl. I'm not making claims it makes an audible difference. And even if it did, it could be very system dependent.

I've never held a Dynaflex record. They were more flexible right? Were they a lot lighter as well? Did they warp easier? They weren't as flimsy as the plastic sheets they used to include in magazines were they?
 
So ideally there should be an energy-damping path from the record to the platter and beyond, and a second one from the cartridge body to the tonearm and beyond.

So in the classic sense, the platter mat serves as the record to platter damper, and I think the cartridge to tone arm damping requirement is pretty well served by the cartridges own compliance to a large extent. It takes it one step further upstream. Its a wonder they never tried designs with a damping system between cart and tone arm, or did they?. All the tone arms I ever used relied on a tight coupling between cart and arm. In the high end lunatic fringe circles even the best of head shells were a no-no.

Although I do remember reading articles about securing your cartridge in place using a quick and dirty damping method. You had to bolt your cartridge to a fixed mount tone arm with standard hardware. Once it was aligned to your satisfaction, you then squeezed silicone calk into the gaps between cart and arm and let it cure. Then you could remove the hardware and squeeze silicone into the voids that were left. I had a Black Widow arm and a Grace 9E that I was considering doing that with, but never acted on it. The Black Widow was already a damped arm (assuming you loaded the fluid into the trough), and I was unsure about interactions and such.

Now I'm recalling the practice in the 70's of pressing modeling clay onto the bottom of turntable platters to damp them more? LOL... the stuff we did back in the day...good times, good times. :phones
 
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I had an Empire cart that had a resonance. Playing records quietly it was loud enough to be annoying. It seemed thin.

There was a NAD table with a damped arm. It was flat, made out of something sort of between rubber and plastic, slightly flexible. It did sound good, I heard some deep bass on that.
 
So in the classic sense, the platter mat serves as the record to platter damper,
I doubt that is the case. I don't see a loose disc pushing enough on the, say, rubber mat to deform it and damp energy, even with a ring.

Hard clamping the center of the record to the platter seems to me to be better. The mass of a heavy platter could be enough to damp the energy, but you can also make a path through the bearing.

and I think the cartridge to tone arm damping requirement is pretty well served by the cartridges own compliance to a large extent.

Vibrations are transferred to the cartridge body by the magnetic components of the cartridge. If there is not a damping path, from there they go back to those components and affect the sound.

It takes it one step further upstream. Its a wonder they never tried designs with a damping system between cart and tone arm, or did they?.

The issue there, I think, would be the extra mass.

All the tone arms I ever used relied on a tight coupling between cart and arm. In the high end lunatic fringe circles even the best of head shells were a no-no.

The regular cylindrical piece that connects the headshell to the tonearm and the assembly in the tonearm that keeps if tight do not seem optimal for vibration transfer, but who knows.

Although I do remember reading articles about securing your cartridge in place using a quick and dirty damping method. You had to bolt your cartridge to a fixed mount tone arm with standard hardware. Once it was aligned to your satisfaction, you then squeezed silicone calk into the gaps between cart and arm and let it cure. Then you could remove the hardware and squeeze silicone into the voids that were left. I had a Black Widow arm and a Grace 9E that I was considering doing that with, but never acted on it. The Black Widow was already a damped arm (assuming you loaded the fluid into the trough), and I was unsure about interactions and such.

Could be enough. I feel more comfortable creating a path and damping downstream.

Of course all of the above could be negligible.
 
This is all in terms of the stylus/ record interface... As the stylus traces the grooves it impacts the groove walls of the record. Any impact causes a vibration. The vibration causes sound which you can hear at a very low level with your ear up close to the stylus as it plays, even with all amplification turned off. The vibrations in the stylus are turned into electrical signals in the cartridge body and eventually get amplified. But the record also vibrates due to the impact, and this is undesirable because now we are adding more vibration beyond what is contained in the grooves back to the stylus. And it gets even worse because the timing is off. The impact of the stylus and record surface produces a limited amount of energy so, if we increase the mass of the record (or do something like couple the record to the turntable platter that many systems do by way of a spindle clamp) we get to a point where the energy we introduce to the record is used up just trying to vibrate the extra mass. It never gets to a point where it starts vibrating wildly because there isn't enough energy available to vibrate that much mass. If we lower the mass, the amount of energy produced by the stylus/ record impact stays the same or nearly so, but now it can excite the record to a greater degree because it is lighter. There is the same amount of energy available to excite even less mass. Also as we lighten it, the resonant frequency of the record increases and gets closer to the audible range where it becomes more problematic. A typically good resonance frequency for a cartridge/ tone arm is like 12 hz or less, well below the limit of human audibility. We don't want to hear the effects of the tone arm (or cartridge body, or cantilever, etc.) vibrating, so we design it all to have its peak resonance below the threshold of human audibility where we cant hear it, even when it does happen. The problem is, each resonance also has harmonic frequencies which are above the audibility threshold and can become audible (although they are lower in amplitude). So a 12 Hz resonance may not be audible, but its harmonics that might occur at 24, 48, 96, Hz are. (i'm not sure where the harmonics actually fall but I doubt they are that evenly spaced).

Here is another way to think about it. Lets keep the record mass a constant and start lightening up the cartridge/tone arm assembly. What happens? As the cartridge becomes lighter and lighter you reach a point where the cartridge starts vibrating so wildly it will jump out of the record groove. How do you solve that? You make the cartridge heavier. Typically we just increase the tracking force, which while not exactly the same thing, produces the same result by shifting more mass to the cartridge side of the tone arm. With your idea, we would just make the cartridge lighter and lighter so there would be less mass to vibrate. Do you think it would stay in the groove then?

This isn't the same thing as reverb in a venue. Reverb is sound hitting a surface and bouncing off. It takes sound time to move, so you hear the direct sound and then a microsecond later, you hear the reflected sound. You can also get standing waves where the sound just keeps bouncing across the same surfaces repeatedly (very undesirable). A resonance is that sound hitting a surface and making the surface itself vibrate (the sound hitting a surface is also an "impact" just like in the record groove). So the bigger the hall, the more surfaces there are to reflect off, the more reverb. How do you control that? You hang sound absorbing panels which are made of a material which is not so rigid and cant vibrate as much as a hard surface. They absorb the sound waves into a material that isn't easy to make resonate.

Cool, very interesting and correct.
You're right about the concert venue was not the best comparison. Thru air you get a lot , but also, there's a lots of Low Frequency info being transmitted that would have my neighbors want to lynch me if I ever tried to replicate it at home...especially having been in the front row of the recent KCrimson lineup a few times...man, those guys are beasts!!! Your body literally shakes!

And I had TOTALLY forgotten about the actual playback you can hear directly by putting your ear next to the cartridge..more or less the RIAA curve...or not...

The dampeners are a neat idea because plastic is easily warped and a lot of LPs have the spindle hole higher than the edges...but I don't think that it would have a part in the whole"resonance". The LP IS in contact with the TT, but I don't think that the playback would be as loud for it to make rubber or whatever material the TT platter is made of. Yes, usually their core is made of aluminum, but that's usually far away anyway...


Curiouser and curiouser...
 
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I do agree with that... I was only pointing out the theoretical ideas behind using the higher mass vinyl. I'm not making claims it makes an audible difference. And even if it did, it could be very system dependent.

I've never held a Dynaflex record. They were more flexible right? Were they a lot lighter as well? Did they warp easier? They weren't as flimsy as the plastic sheets they used to include in magazines were they?

Yes, I understand and know about the theories and yes according to theory, a thicker record should not be excited as much when external forces impinge on it. It takes more energy to get more mass moving, etc.

The original Dynaflex records, released in the very early seventies (some have claimed some were released as early as 1969) were extremely thin and light although not a thin as magazine flexi-discs. They could almost be literally bent in half and return. RCA claimed they would actually be less prone to warping because the thinner plastic disc would straighten back out more readily than a thicker disc. I don't think anybody ever definitively determined whether normal thickness records or Dynaflex records were more prone. Since normal thickness records would be less prone to warping to begin with, I think it's pretty much a wash.

As time went by, the thickness of Dynaflex records varied and gradually became thicker until Dynaflex was abandoned. Of course, the claims came that RCA's real reason for Dynaflex was to save on material costs which may or may not have been true. Their introduction pre-dated the 70s energy crisis by several years although that would not stop a typical manufacturing company from trying to cheapen the manufacturing process.

My comment about CD-4 records is a result of my observations of those records disproving some of the claims made about playing regular two channel records. Since tracking of CD-4 records is much more critical than that of tracking two channel records (because of the 30 kHz carriers), They will uncover shortcomings in a turntable/cartridge more readily than regular records will.

Anyway, it's an interesting discussion and your posts are most informative.

Doug
 
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