[*Scotty*]

If I were trying to find differences using this methodology, I would use very short duration impulse test signals. Differences that might not show up with steady state sine wave test signals, might be revealed under dynamic test conditions.
Scotty

[S Clark]

...I wonder if companies that claim to cryo tubes actually do anything. Maybe they just re-pack the tubes and ship them back to you. How would anyone know if they did or not?...
--Ethan

It sure looks like you are suggesting that the guys that do cryo are charlatans, liars, and thieves.  What about you guys that sell room treatments?  Few if any actually measure and do the math to make sure that the diffusers you sell are something other than some random cuts on your table saw?  Are your absorption panels nothing better than lightweight foam?  I remember reading that you use a stereo receiver to power your rig; what else do you do your evaluations with?

Perhaps you would like to moderate your earlier derogatory speculation? I don't think this helps your status as an "audio expert".

[sts9fan]

http://youtu.be/z3uqjuOg8xw
Consider this a warning

Seems to me if a person knew how to make real audio devices they would not start a  cryo business.

[srb]

http://youtu.be/z3uqjuOg8xw
Consider this a warning

I don't get it.  I've been warned that the linked techno pop video has nothing to do with cryogenic treatment ?

Steve

[sts9fan]

Yup

[neekomax]

Well, that was super random. 

At least it was a good track.

[Ethan Winer]

a null result is not confirmation or repudiation, it's a null result, it means you didn't find anything.  A null result can only suggest, not confirm.

Scotty already explained why this is not true. A null test is absolute proof that cryo'ing a wire has no affect on the signal passing through it. Unless of course it shows that there is a difference. The burden of proof is on those making the claim. Read the link Scotty posted. Until the cryo proponents show some proof, I'm sticking to my informed opinion.

--Ethan

[Ethan Winer]

It sure looks like you are suggesting that the guys that do cryo are charlatans, liars, and thieves.

Mostly I've said that logically speaking, cryo seems unlikely to change anything, and that the burden of proof is on the vendors. I also pointed out that cryo vendors never provide proof.

What about you guys that sell room treatments?  Few if any actually measure and do the math to make sure that the diffusers you sell are something other than some random cuts on your table saw?  Are your absorption panels nothing better than lightweight foam?

What part of the Before and After acoustic treatment images below do you not understand?

I remember reading that you use a stereo receiver to power your rig; what else do you do your evaluations with?

I do have a stereo receiver in my home theater. What's wrong with that? Please be very specific!

Folks, bear in mind this is The Lab where discussing audio science is expected. Science means real effects, repeatable results, and proper test methods - not imagined benefits that can't be proven.

--Ethan

[BobM]

Just got back some cryo'ed tubes. This is my first foray into cryoing, and I am typically a skeptic until I hear otherwise, but am willing to try, test and learn. They are burning in now and I should have something to say about them vs the same tube non-cryoed shortly.

[*Scotty*]

Actually, before a null test will show anything, one has to be performed on something that has cryo treated.
On another note, here is my waterfall plot with two Aux subs operating out of phase.

My waterfall shows a worst case 30db of decay in 300ms at about 32Hz.
No room treatment other than subs operating out of phase with front mains.
Scotty

[neekomax]

Actually, before a null test will show anything, one has to be performed on something that has cryo treated.
On another note, here is my waterfall plot with two Aux subs operating out of phase.

My waterfall shows a worst case 30db of decay in 300ms at about 32Hz.
No room treatment other than subs operating out of phase with front mains.
Scotty

A little OT, but I never know what the hell I'm looking at when I see these graphs. Does anyone have a link that explains like I'm five?

[*Scotty*]

I'll try to explain the graph I put up. In the simplest terms a waterfall plot is a way of seeing an echo and how long the echo takes to die out. In the graph I posted the amount of time we are looking at is 300 milliseconds and the dB range covered by the signal is from a peak level of about 62db at the top of the mountain range to 15dB at the bottom for a total dB range of about 45dB. In some cases the signal decays right into the floor well inside the 300ms time window. I can make this graph look better by showing you less of it, say only the first 20db of decay, this is done by raising the floor and covering up what is happening to the decay below the that level. You can also apply smoothing to the graph which is like putting joint compound in the cracks so they don't show up in the graph. I think a waterfall graph is one of the easiest to use to misrepresent what is happening when a driver or room is measured. It is possible to manipulate it to the point that it shows no pertinent information at all.
Here is the same information that is shown is the first graph with only the first 20dB of decay shown, no smoothing and no other manipulation of data.

Scotty

[neekomax]

I'll try to explain the graph I put up. In the simplest terms a waterfall plot is a way of seeing an echo and how long the echo takes to die out. In the graph I posted the amount of time we are looking at is 300 milliseconds and the dB range covered by the signal is from a peak level of about 62db at the top of the mountain range to 15dB at the bottom for a total dB range of about 45dB. In some cases the signal decays right into the floor well inside the 300ms time window. I can make this graph look better by showing you less of it, say only the first 20db of decay, this is done by raising the floor and covering up what is happening to the decay below the that level. You can also apply smoothing to the graph which is like putting joint compound in the cracks so they don't show up in the graph. I think a waterfall graph is one of the easiest to use to misrepresent what is happening when a driver or room is measured. It is possible to manipulate it to the point that it shows no pertinent information at all.
Here is the same information that is shown is the first graph with only the first 20dB of decay shown, no smoothing and no other manipulation of data.

Scotty

Ok, thanks, that helps. So, my next naive question is, what does the ideal waterfall graph like this look like? IOW, what does 'good' look like? Uniform decay times across all frequencies?

[*Scotty*]

I would call that a worth while goal. It is easier achieve at frequencies above the Schroeder frequency, which is usually lower than 250Hz depending on the rooms dimensions.
Here is a full frequency sweep waterfall with 1/12th octave smoothing applied. This might not be a bad result, it sounds okay to me.

Scotty
Definitely off topic, cryo treatment appears to do something to audio components to my ears, but I am unaware of any valid scientific testing involving before and after null testing.

[sts9fan]

I fail to see how waterfall plots relate to cryo?
Stay in topic and no "you do x so you can't talk about y". It's a poor argument.

[neekomax]

I fail to see how waterfall plots relate to cryo?
Stay in topic and no "you do x so you can't talk about y". It's a poor argument.

I have no idea what the last bit means, x and y business. Anyhoo.

Definitely off topic, which I acknowledged when I posed my little beginners question, and why I asked for a link, not an explanation.

Also, I'm not sure that your random youtube music video was entirely germane to the discussion either, although it was a cool song.

As I recall, Ethan posted waterfall graphs to give an example of demonstrable change in sound, to illustrate that anything that can be heard, can be shown. He did this because he was challenged on a related assertion.

.... aaaaaand back to cryo.

[Ethan Winer]

what does the ideal waterfall graph like this look like?

Look at the Before and After waterfalls I posted just yesterday. The red graph is for an empty room, and the purple is the same room after adding bass traps. Much more about how to read these graphs here:

Room Measuring Primer

Uniform decay times across all frequencies?

Yes, and not just for bass frequencies. This shows Before and After broadband reverb decay times for the same room:



Notice how the green line shows not only much less never generally, but the variance is less too.

--Ethan

[Ethan Winer]

Oops, double post.

[Audioexcels]

Just got back some cryo'ed tubes. This is my first foray into cryoing, and I am typically a skeptic until I hear otherwise, but am willing to try, test and learn. They are burning in now and I should have something to say about them vs the same tube non-cryoed shortly.

What were your results out of curiousity and if there are differences, what tube sounds better and in what way?

Thanks!

[wakibaki]

I wonder if companies that claim to cryo tubes actually do anything. Maybe they just re-pack the tubes and ship them back to you.

I don't think this helps your status as an "audio expert".

It certainly doesn't hurt his reputation as a judge of human nature.

w