VSONIC VC02 - Info & Appreciation Thread - Page 28

Quote:

Originally Posted by mikeaj 

 

late response (Click to show)

I know this is not directed at me and I'm late here, but anyway... Is there much justification for believing that some small things added together might make a significantly larger difference?  By "add" I think we mean the combination of different elements or metrics, not some arithmetic addition.  I don't mean to dismiss it outright as a possibility, but it doesn't seem like an obvious working assumption to make.

 

You mention averaging out effects from different tips, insertion depth, one IEM sample vs. another, etc., which I agree with in principle.  Actually doing so, or extracting the information we want out of the data when there are a lot of confounding variables of unknown influence, is a different matter.  Some caution is warranted because the effects from these kinds of things (at least, as measured by the parameters people look at such as FR, nonlinear distortion) are often significantly greater than any effect due to break-in, if data from various sources is to be believed.  And any comparison based on auditory memory of course will have some relatively large degree of uncertainty, which needs to be addressed.

 

I agree about voice coils not increasing in impedance when cooled.  Doesn't make sense, unless I'm missing something about the mechanical and acoustic properties of the system.  A wire should definitely have higher resistance at higher temperatures.  Anyway, many headphones change impedance when clamped on a head; it's very reasonable that some change in the mechanical structure should be able to make some difference in impedance too.  Should be apparent when looking at the equivalent electrical model of a transducer (i.e. that takes into account the mechanical and acoustic parts).

Thanks for your ideas on the subject.  When I say that he makes the assertion, we actually don't know if the small things together will make a difference.  We really don't.  So I didn't say it will, I asked if it could.  In actuality, unless we know how sensitive things are, we really won't know.  

As for different tips, I stated against that, we would use the same tips, I have no clue why Inks brought that up.  Insertion depths can be averaged out, as you use the IEMs more, you get into a more stable insertion depth.  Using multiple IEMs can help with driver inconsistencies.  As for memory, we people do headphone comparisons, that's basically the same time frame here.  The memory comes in seconds, not hours.  We are comparing a number of VC02s, not just 1.  A set not burned in, a set burned in.

As for looking at the impedance, it confuses the heck out of me.  I have no explanations, but the data is there.  For some odd reason, it goes down with burn in.  Inks says it goes back up, I don't believe that (I would guess it would go further down when cooled).  From the data, we know something caused it to drop when burning in.  After burning in, there really is nothing to cause it to go up (EG it should follow the path that would go down).  

We also have the changes in the waterfall plots that haven't been addressed yet either.  No data showing or stating otherwise.  I have doubts that the frequency shift created losses and gains in the decay of the IEM.  I could be wrong though.  

Please do note, that I'm not for or against burn in.  I honestly am stuck in the middle.  But seeing people make the assumptions that the ear won't pick this up or that up or these up, well, the ear is more sensitive than you'd think it is.  What really ticked me off the most is that the person I was talking to refuses to give any data showing otherwise, stating its a waste of time and there is no need to.  Something just feels very fishy with the data he's hiding, like he doesn't want anyone to see it.  I feel like he is hiding something to cover his tracks.  

I think a lot of the books and info published on loudspeakers should be relevant, especially as a headphone / IEM dynamic driver is mostly the same thing, miniaturized.  I guess that's even more so for something like the VC02 and its really tiny driver.  The magnitude of importance of different things may be significantly lower because of the difference in mass and so on, but it's known that Thiele-Small parameters do change over time (more so at the start and less so later on; definitely no "flip the switch" kind of change after 80 hours or 200 hours or some magical mark).  Probably has to do with elasticity and mechanical properties of the driver, mechanical damping, etc.

See the rough lumped electrical system model at the bottom here:

http://en.wikibooks.org/wiki/Engineering_Acoustics/Moving_Coil_Loudspeaker

Differences in the mechanical and acoustic properties will be reflected back in the speaker impedance as tested, at least when not at DC.  Not sure how accurate you can take the model, as I have not read on these things and don't have experience here.

It's just a matter of magnitude of break-in or burn-in or whatever you call it, whether these things are noticeable.  According to the kinds of changes actually evidenced... maybe it's possible, but generally they do not seem to line up with peoples' impressions of the changes, both in magnitude and character.

In general I would experiment more with tips or otherwise modify the enclosure or damping, than worry about break-in effects, anyhow.

Back to the regular scheduled programming, sorry guys.

I found an interesting excerpt from a page on the web...

Paul Roth of Credence Speakers Inc. responds.

Paul is a design engineer at Credence. http://www.credencespeakers.com/ They have been in business since 1976.

Paul pointed out to me that on the measurements made right after running it hard for 20 hours, I either failed to show the slight changes in Re (changes from being hot) or I rounded back to the first decimal and did not change it. This is likely one of the reasons for the slight changes in Mms and BL on that measurement. A smaller but similar effect can be seen when I tested the woofer after running it hard for 10 seconds. Once cooled those numbers shifted back. He said that he usually allows 10 to 12 hours of cool down time before running T/S parameters following a break in period.

Here is his response that he said I could quote:

At any rate, excepting the tests run right after the break-in, where I question the numbers, esp. Mms, your data looks ok to me & consistent with THOUSANDS of measurements I have done. Anyone who thinks a woofer's parameters don't change due to break-in / burn-in is either ignoring the data, has lousy data, or is not doing much of a break-in. Granted that the effect on the in-box measured curve, due to break-in / burn-in, may or may not be significant, depending on the box.

Paul Roth 7-17-06

I found it interesting - now they are talking about woofers, but the idea is the same for a dynamic IEM. More here...

http://www.gr-research.com/burnin.htm

Quote:

Originally Posted by mikeaj 

I think a lot of the books and info published on loudspeakers should be relevant, especially as a headphone / IEM dynamic driver is mostly the same thing, miniaturized.  I guess that's even more so for something like the VC02 and its really tiny driver.  The magnitude of importance of different things may be significantly lower because of the difference in mass and so on, but it's known that Thiele-Small parameters do change over time (more so at the start and less so later on; definitely no "flip the switch" kind of change after 80 hours or 200 hours or some magical mark).  Probably has to do with elasticity and mechanical properties of the driver, mechanical damping, etc.

 

See the rough lumped electrical system model at the bottom here:

http://en.wikibooks.org/wiki/Engineering_Acoustics/Moving_Coil_Loudspeaker

 

Differences in the mechanical and acoustic properties will be reflected back in the speaker impedance as tested, at least when not at DC.  Not sure how accurate you can take the model, as I have not read on these things and don't have experience here.

 

It's just a matter of magnitude of break-in or burn-in or whatever you call it, whether these things are noticeable.  According to the kinds of changes actually evidenced... maybe it's possible, but generally they do not seem to line up with peoples' impressions of the changes, both in magnitude and character.

 

 

In general I would experiment more with tips or otherwise modify the enclosure or damping, than worry about break-in effects, anyhow.

 

 

Back to the regular scheduled programming, sorry guys.

Very interesting article, thanks.  And it does have to do with magnitude, however, we don't know how to "measure" the magnitude of burn/break in.  In order to really measure it, we have to know what causes it.  No one knows what causes it, in my honest opinion, I'd put my money on multiple factors, not just the driver, but as you stated, the tips as well (or pads in terms of actual headphones).  I'm unsure if you've ever noticed it, but tips tend to warp over time into a more elliptical shape that matches that of your ear.  That change in seal can cause change.  The measurements Rin took also show that we are not just talking tips though, we also see some odd results that show something is happening to the driver, we just don't know what.

Whether or not we hear it is a whole other question.  We can't answer that until we understand break in itself as well as further psychoacoustics.  

Quote:

Originally Posted by Ivabign 

I found an interesting excerpt from a page on the web...

 

 

Paul Roth of Credence Speakers Inc. responds.

Paul is a design engineer at Credence. http://www.credencespeakers.com/ They have been in business since 1976.

Paul pointed out to me that on the measurements made right after running it hard for 20 hours, I either failed to show the slight changes in Re (changes from being hot) or I rounded back to the first decimal and did not change it. This is likely one of the reasons for the slight changes in Mms and BL on that measurement. A smaller but similar effect can be seen when I tested the woofer after running it hard for 10 seconds. Once cooled those numbers shifted back. He said that he usually allows 10 to 12 hours of cool down time before running T/S parameters following a break in period.

Here is his response that he said I could quote:

At any rate, excepting the tests run right after the break-in, where I question the numbers, esp. Mms, your data looks ok to me & consistent with THOUSANDS of measurements I have done. Anyone who thinks a woofer's parameters don't change due to break-in / burn-in is either ignoring the data, has lousy data, or is not doing much of a break-in. Granted that the effect on the in-box measured curve, due to break-in / burn-in, may or may not be significant, depending on the box.

 

Paul Roth 7-17-06

 

I found it interesting - now they are talking about woofers, but the idea is the same for a dynamic IEM. More here...

 

http://www.gr-research.com/burnin.htm

Many make the claim, and they are free to do so that a smaller driver won't surcome to as much change because it's, well small.  We don't know the relation between size and audibility, so they are free to make that claim (better yet, question; it really isn't a true claim yet).  Then I question, smaller driver through a smaller system might be audible, is it?  It's a really good article though, gives a lot of insight.  I do still need to say, many people who don't feel headphones break in use the fact that we are using headphones to nullify those findings.  

I honestly feel we need to look at relative changes of all measurements, not just absolute.  I can say there was .0001 mm change in absolute, but it turns out the change came from .0002, well, that's a 100% relative change, that's quite large.  

Quote:

Originally Posted by mochill 

If you can't here an audible difference after burn in then you must be deaf or ignorent to the fact of hearing .

I wouldn't go this far with the statements my friend.  There are a lot of people who truly don't hear the differences.  I would believe them too.  However, I'm after the reason why some will hear it, some will not as well as how it works underneath (as that will help answer the first question).  

Quote:

Originally Posted by JonnyRocket 



This is why I said to get a couple of pairs of theses, I think they're around $30 for two on amazon and you could probably return them when your done.

You found the VC02 for $15 on Amazon?

Where?!

Quote:

Originally Posted by scootsit 

You found the VC02 for $15 on Amazon?

Where?!

I wish to know this as well ^^

Maybe he's talking about another pair of phones.

Quote:

Originally Posted by JonnyRocket 

Quote:

Originally Posted by scootsit 

You found the VC02 for $15 on Amazon?
Where?!

I apologize, I was talking about the JVC Ha fx1x

Ah, you got my hopes up!

Have any of you VC02 guys previously tried the JVC HAFX40's? How do they compare, SQ wise? The VC02 has better build quality from the pics Im seeing, not surprising considering $40 compared to $15 price range though. 

I got the FX40's a couple of days ago, as it was one of those justified hyped IEM's. Its one of those IEM's where burn-in makes a world of difference due to the carbon nanotubes (just to add in to the burn in argument earlier). 

Looking at getting another set of IEM's to complement them and the VC02 have caught my interest since the first post on here (due to removable cord and build quality). 

Thanks.

fx40 is a v-shaped signiture and not as cohernt as the vc02 , i have most of the iem on the discovery thread. the vc02 is awesome. it is much higher quality sound compared to jvc, the vsonic house sound is much of better the jvc as i know because i have alot of iem xD.