I must have hit a nerve or something. Anyway, maybe I did not state my position clearly.
I understand the reason for cyro treatment after the material is heated to a cerntain temperature to change its properly. This is not the case from what I have understand about the current state of Audiophile "Cryo" treatment. They simply freeze object of desire. That makes no sense.
Let me give you an example for why it would work.
Heat up a piece of Cu to around 500C. Solid state diffusion will start rapidly and grain size will grow. If you put that piece of Cu under some kind of physical or magnetic force, the grain will grow in one particular directly. Now just sudden drop the temperature to a much lower temperature will freeze the grain in that state.
This is basically what happened a long grain Cu speaker cable is made. (Any piece of Metal is usually made of millions of small grains)
Now a counter example:
The metal is already in a solid state in room temperature or < 100C. Drop it into a liquid nitrogen. It's not going to change the structure of the metal at all. As soon as it return to room temperature, it's no different than before.
Someone mentioned glass, an amorphous material. That means it's in a solid form and can change somewhat at very low temperature. (< 50C) Still, just drop a tube in liquid nitrogen will just put lots of stress on the tube unnessarily and likely shorten its lifetime. Still does very little.
Eric |
Cello,
Can you point out the double blind studies that shows statistically benefit sonically?
HDM,
When you say that "cryo" treatment consistently shows an improvement, that's actually a worrisome statement to me. That usually shows a rather biased opinion.
Can you point out the link that shows the resistance measurement that says the resistance is lowered after treatment? That would be an interesting read.
Lugnut,
Engine block consitently operates at fairly high temperature and come back down. It does not surprise me that Cryo can do something but it has more to do with the heat and cryo cycle treatment.
All,
In order for change to occur in the micro-structure of a metal, you will need some kind of heat treament. Simply cryo will not do it.
If "cryo" and then some mechanical treament, physical change can take place but that is all macro-structure. That means break or crack the material when it's very brittle at low temperature.
Once again, none of the evidence offered up so far means very much to me. I was looking for someone to come up with a better scientific answer other than "I heard it; therefore, it's better".
Eric |
After reading through all these posts, I think I am going to give up. So far, no one can come up with a good reason why "cryo" treatment alone works. Thus far, the best reason thus far is "because I experienced/believed it".
Put it in another way. Quite a few people not long ago argue that earth is the center of the universe because they believed so. I think we can do better than that in 21st Century.
Regarding DBT and statiscally significance, it takes roughly 8 correct answers out of 10 trials of ABX to be somewhat significant. Usually 9 corrects out of 10 is considered valid at >95% confidence interval. That's why most audio improvement can't really be tested using ABX. It's not because there is no improvement, but because human audible memory typically is a lot worse than that. After 3-4 trials, all things tend to jumble up.
I normally do not ask for a DBT for proof because a negative result actually proofs anyting. It just says that the difference can't be detected under the circumstance. Not very usefully in my opinion.
I only brought it up because Cello offered it up as evidence. Once again it's one of those insignificant results. It's certainly not his fault. It's quite difficult to set a good DBT ABX test.
Eric |
Geoffkait,
Please go through my post again. Cold tempering requires heat treatment cycle. Not cooling from room temperature, which is what's in vogue right now in Audio.
Cello,
Please try to under this. When you make a scientific claim such as DBT testing, the test result must be statistically significant. Otherwise, it's just pseudo-science.
Eric |
John,
For martensitic formation to occur, steel needs to be heated well above room temperature first. That temperature will depend on the composition of the steel. (how much carbon and other metal additive and etc) Again, a heating cycle is needed.
For a reaction to occur, a driving force is needed. (physical force, thermal, elctro-magnetic and etc) Reducing the temperature certainly will not provide that driving force.
This brings up another theory for me. If you combine cryo treatment with some kind mechanical machining at the lower temperature, you can potentially change the micro-structure due to internal stress difference and mechanical force; however, this is not what I have understood about today's Audiophile "cryo" technique. From what I read in the brochure, it's dipping the desired object in a cool solution.
Eric |
Cello,
I will make this my last post on the subject to avoid your claim of I "being a troll".
The point I want to make is this: I am curious about Cyro treatment and its claim. So far I have not yet heard a credible scientific theory that makes it work. All of them are guesses and subjective testing. In fact, I have only read a good scientific explanation on why it would not work.
It's quite ok to claim benefit of cryo treatment because you heard the benefit. It's quite another to claim that there is a scientific reason behind it. As I mentioned in my earlier post, I often make large audio purchase based on subjective testing. In fact, I typically doubt DBT ABX testing due to its difficult set up and psycho-acoustical issues.
So, when someone makes a scientific claim, I would very much like to see the actual research going into it.
Let me put it another way. Let's say you send back the cryo CD and I told you it did absolutely nothing. Would you agree that "cryo" does not work? Of course not. Just the same that if I told you it worked great, it still does nothing to prove the scientific claim.
Aruging about subjective testing is pointless.
Lugnut,
Please read Jneutron's post about heat cycle's roll on cyro treatment of solid metals. There is not too much more I can say on the subject. You can disagree based on your experience, but it's kind of difficult to argue about numbers.
Eric |
Ok. I am baited into posting with another answer. Since I started, I might as well finish it.
Cello,
I believe this is a "tech talk" forum. I thought this is the place to discuss about the science/technology behind the product. I was looking for a reasonable theory for an audiophile "fab". I purposely did not post the question in cable forum for that.
Whether I hear the difference in a "cryo" CD does not prove or disprove the possible theory.
Lugnut,
I received my MSE from Stanford University in 1996 and BS in electrical engineer and MSE double major from UC Davis in 1994. For the last 8 yrs, I have been working as a process engineer in a semiconductor capitol equipment company working on CVD product. So most people would say that I have a ok background in thermodynamic, electrical engineering principles, plasma physics, semiconductor physics, gas dynamic, metallurgy and associated process treatment.
I think that's enough background to post a likely theory and ask a question about "Cryo" treatment on audiophile product.
Having a shoot-out means very little to this discussion. There is nothing wrong with subjective listening test. I do all of my purchasing based on subjective listening test; however, it has very little to do with science.
Eric J Liu (feel free to look it up) |
John,
the point I am making is that the starting phase of the steel must be in austenite. Once quench to to a lower temperature. Martensitic transformation occurs. Certain percentage of the marensite is formed, but the other material do not stay in Austenite phase. All the left over goes into Pearlite or Ferrite depending on compostion.
So any further quenching will not continue the martensitic transformation. The material must be raised back to a higher temperature level and reform Austenite before that's possible.
Put it another way. A piece of Steel can have a dramatic phase change by dropping rapidly from 900 to 20C, but that change is near permanent. Dropping the temperature from 20C to -150C do not continue the phase change. You must heat back up above ~800-900C to reform the inital Austenite phase.
The driving force for the martensitic transformation is the instable crystal structure of Austensite at lower temperature. So without forming austenite again. The driving force is gone.
For anyone who is interested, check out an example of phase diagram: (note that phase diagram changes rapidly depending on level of impurity.)
http://www.sv.vt.edu/classes/MSE2094_NoteBook/96ClassProj/examples/kimcon.html
For amorphous material like glass, the temperature change will mostly introduce lots of stress on the material. Eventually it formed a solid. The phase change most likely will cause physical breakage. Not sure what would be the audible effect, but I think the end result would most likely lower reliability.
Eric |
Let me try to answer some of them.
For 1 and 2, at normal operating temperature, (room temp to 100C), there will be not be any significant change to the internal structure of the material, but the surface of the metal can oxidize easier. Mechanical movement by twisting and pulling can cause more change in micro-structure than temperature at this range. For example, if the speaker cable design emphasize large grain micro-structure (Audioquest LGC), simply twisting the long cable will cause the long grain to break up into shorter grain structure. The effect can be worsen at lower temperature because the bonding strength is lessen at lower temperature.
So it's likely reversible, but the process can be quite complicated. I would think that material is best designed into manufactoring instead of some tweak.
3) Change in the stress of the metal will have to do with the Macro-structure or mechanical design. For example, a tight fitting metal o-ring undergoes cryo treatment only. The fitting might not be so good afterward because the overall shape have changed due to thermal stress cycle or thermal stress hysterisis. The micro-structure or material itself probably have not change that much.
4) Sorry. Can't comment on it.
5) DBT is very simple. Just make sure the listner and test giver do not know the actual test being run. For ABX, it's ok for the listner to get familar with the music passage first before the test. So, listen to A, listen to B and then listen to X. The listner writes down if the X is A or B. Repeat the same passage at least 10 times. If the listener can consistently get the correct answer 9 out of 10 times. It's statistically significant.
Very tough listening test in my opinion. I can't remember the difference that well. After 2-3 tests, everything sounds very much the same. It's also very impratical for multiple listner because of narrow sweet spot.
Eric |
HDM,
Lost_in_space's question 1, 2 and 3 are very general engineering questions. They can be answered by engineers with some background in thermal dynamic and material science.
I don't and can't comment on sound effect of "Cryo" treatment. So I did not. You however have experienced on such matter and tried it in a long term setting. How do you attribute the difference to "cryo" treatment? In my own subjective test, I often have difficulty pinpointing one single item as the source of difference. There are just so many variables to content here.
For example, I have often asked my wife to be the test subject and found that I can easily make something sound better simply by turning the vol about 1-2dB louder. It's rather amazing.
Another question for you on the cryo power outlet, which is more likely?
1) The "cryo" treated power outlet's contacts are cleaned and has better contact with AC plug and therefore better sound.
2) A "cryo" power outlet has a special property that results in better sound.
Why do lots of people around here always pick 2)? Is it because of the pretty pseudo science ad?
Eric |
Interesting discussion from everyone. It's very similar to a discussion on proving existence of God.
Group A states that God must exist because they believes it to be so. Don't ask why. Just follow their "truth".
Group B simply asked to see if it's possible to scientifically prove God's existance. And they are treated as heretic and must be casted out of group A's wonderful society.
Maybe we should have a new policy on Audiogon's tech forum.
"Don't ask. Don't tell". Just follow the gospel according to "sohpiscticated audiophile".
Anyway, I will give up for sure now.
Eric |
