[mtthefirst]

Just got an email from Fitear about my MH335DW (in japanese T^T). From my little knowledge in japanese, google translate, and japanese assistance professor in mechanical engineering that sit next to me, this is their response.
 
The say that the "crack" that I mention is not actually the "crack" but is the interface between their acrylic shell and the resin that they used for filling up the shell. They measure the distance from the tip to the "crack" location and confirm that those 2 mm from the tip is actually the thickness of the acrylic shell of the stem. They said this could happen and won't effect the performance of it.
 
I also wrote back to them informing about other fracture that I found on both stem and waiting for their reply.

 

[tm.chen]

Hope they can do something about it for you.

 

[tranhieu]

Quote:

Just got an email from Fitear about my MH335DW (in japanese T^T). From my little knowledge in japanese, google translate, and japanese assistance professor in mechanical engineering that sit next to me, this is their response.
 
The say that the "crack" that I mention is not actually the "crack" but is the interface between their acrylic shell and the resin that they used for filling up the shell. They measure the distance from the tip to the "crack" location and confirm that those 2 mm from the tip is actually the thickness of the acrylic shell of the stem. They said this could happen and won't effect the performance of it.
 
I also wrote back to them informing about other fracture that I found on both stem and waiting for their reply.

Are they referring to your left earpiece? 

 

[mtthefirst]

Quote:

Are they referring to your left earpiece? 

Yes. This email was send after they take a look at my 335. I ship it to them the day before.

 

[tranhieu]

Quote:

Yes. This email was send after they take a look at my 335. I ship it to them the day before.

That's strange. From the look of it I don't think that's the surface of the resin used to fill up the hollow canal (speaking from my own experience as someone who built several CIEMs in the past). 
 
I mailed the guy who's the sale manager of a big distributor for uv acrylic used in audiology in the US, and being a former audiologist himself, he never heard of canal tips cracking due to temperature change before. Though that doesn't mean it cannot happen.
 
Don't get me wrong, FitEar is the most respectable CIEM company to me, but I don't find that answer satisfying at all. 
 
Just my 2c.

 

[mtthefirst]

Quote:

That's strange. From the look of it I don't think that's the surface of the resin used to fill up the hollow canal (speaking from my own experience as someone who built several CIEMs in the past). 
 
I mailed the guy who's the sale manager of a big distributor for uv acrylic used in audiology in the US, and being a former audiologist himself, he never heard of canal tips cracking due to temperature change before. Though that doesn't mean it cannot happen.
 
Don't get me wrong, FitEar is the most respectable CIEM company to me, but I don't find that answer satisfying at all. 
 
Just my 2c.

 
I'm also didn't satisfy with their answer too. I'm not familia with polymer but I got some basic knowledge from my PhD in material science and engineering. I can say that what they are saying that those "interface" (whatever they're calling) won't affect the performance is wrong. It's clearly defect in the earpiece. In the long run, those defect will become the source for crack inside. Change in the color inside those transparent shell indicate one thing that there is some discontinuity in the material and it will easily propagate. The main obstacle for me is japanese. I can communicate with them in japanese. 

 

[tranhieu]

Quote:

 
I'm also didn't satisfy with their answer too. I'm not familia with polymer but I got some basic knowledge from my PhD in material science and engineering. I can say that what they are saying that those "interface" (whatever they're calling) won't affect the performance is wrong. It's clearly defect in the earpiece. In the long run, those defect will become the source for crack inside. Change in the color inside those transparent shell indicate one thing that there is some discontinuity in the material and it will easily propagate. The main obstacle for me is japanese. I can communicate with them in japanese. 

Do you have any photo of the left piece with its concha showing? Normally FitEar always fill the internal space of the shell past the drivers, sometime half the shell. Yours should be the same. 
 
 
I suspect they meant something else by 'interface'. 2mm deep is too shallow.
 
 
On the side note, someone with username 'Kindo3' is reading this thread at the moment. I guess that's Suyama-san himself? 

 

[mtthefirst]

Quote:

Do you have any photo of the left piece with its concha showing? Normally FitEar always fill the internal space of the shell past the drivers, sometime half the shell. Yours should be the same. 
 
 
I suspect they meant something else by 'interface'. 2mm deep is too shallow.
 
 
On the side note, someone with username 'Kindo3' is reading this thread at the moment. I guess that's Suyama-san himself? 

 
Here is the picture of my MH335DW. It's filled with resin to almost the entire shell. About 2 mm, I might be wrong with the translation but it might referred to the diameter of the bore.
 

 

[tomscy2000]

Quote:

  On the side note, someone with username 'Kindo3' is reading this thread at the moment. I guess that's Suyama-san himself? 

 
Nice catch!

 

[mtthefirst]

Quote:

 
Nice catch!

 
Is it him?
 
I'll wait for their response. I might request them to make me a new pair. It's clearly manufacturing defects. They can argue that I won't affect the performance of the phone but even those crack make my professor in our laboratory concerned. Our institute is called "Fracture and Reliability Research Institute". Our expertise is behavior of crack in materials. 

 
 
This time I'll write to them in english.

 

[spkrs01]

Quote:

Just got an email from Fitear about my MH335DW (in japanese T^T). From my little knowledge in japanese, google translate, and japanese assistance professor in mechanical engineering that sit next to me, this is their response.
 
The say that the "crack" that I mention is not actually the "crack" but is the interface between their acrylic shell and the resin that they used for filling up the shell. They measure the distance from the tip to the "crack" location and confirm that those 2 mm from the tip is actually the thickness of the acrylic shell of the stem. They said this could happen and won't effect the performance of it.
 
I also wrote back to them informing about other fracture that I found on both stem and waiting for their reply.

 
I think it is probably true what they say. If you look at the MH335DW with coloured tips such as V0 or anakchan's, that is the exact place where the acrylic colour tips end..........
 

 
It is unfortunate that when you choose clear tips, the contrast of the two different materials is so noticeable......
 
EDIT: I should add that I am just speculating here, as this seems to be the most logical explanation.

 

[mtthefirst]

Quote:

 
I think it is probably true what they say. If you look at the MH335DW with coloured tips such as V0 or anakchan's, that is the exact place where the acrylic colour tips end..........
 
It is unfortunate that when you choose clear tips, the contrast of the two different materials is so noticeable......
 
EDIT: I should add that I am just speculating here, as this seems to be the most logical explanation.

 
Yes, their explanation is reasonable but the fact that it won't cause further damage to the phone is still trouble me.

 

[shigzeo]

Hi guys, I've been asked by Mr. Suyama to help out with communication between custom customers and the FitEar office. I think Mr. Suyama trusts my Japanese more than I do, but I am relatively familiar with FitEar products and should be able to help out with the 'crack'. Evidently, as noticed late in this thread, it isn't a crack. When the resin dries, it can contract. It simply is unavoidable with today's manufacturing process especially with a fully solid acrylic/resin shell. Also, as noted, there is no effect whatsoever on sound or longevity of the earphone. It is 100% a cosmetic effect. 
 
I will chime in with more information as I have it. 
 
Please don't PM me with questions; it is better to keep questions in this thread so that anyone can access the information. 
 
I will be gone to Hong Kong from Saturday and probably not attached to internet. I come back Wednesday next week.
 
Otherwise, I'll be in this thread to help out. I expect that Frenchbat will be here eventually, too, as he got a 335!

 

[tranhieu]

Quote:

 
Nice catch!

Cheers. Nice avatar btw! 

 
Quote:

Hi guys, I've been asked by Mr. Suyama to help out with communication between custom customers and the FitEar office. I think Mr. Suyama trusts my Japanese more than I do, but I am relatively familiar with FitEar products and should be able to help out with the 'crack'. Evidently, as noticed late in this thread, it isn't a crack. When the resin dries, it can contract. It simply is unavoidable with today's manufacturing process especially with a fully solid acrylic/resin shell. Also, as noted, there is no effect whatsoever on sound or longevity of the earphone. It is 100% a cosmetic effect. 
 
I will chime in with more information as I have it. 
 
Please don't PM me with questions; it is better to keep questions in this thread so that anyone can access the information. 
 
I will be gone to Hong Kong from Saturday and probably not attached to internet. I come back Wednesday next week.
 
Otherwise, I'll be in this thread to help out. I expect that Frenchbat will be here eventually, too, as he got a 335!

 
It's true that the resin used to make shells will contract as it's cured under UV, but the shrinkage ratio would be minute, especially with that tiny volume. And it only contracts under UV, not temperature nor anything else AFAIK.
 
Perhaps FitEar uses other type of resin for filling the hollow shells? I wouldn't mind if this question is left unanswered as it touches the sensitive part of their business. I'm just asking since normally people use the same type of resin for making shells to fill the canal.
 
I'm also with FitEar on it being nothing but cosmetic defect. Though it's a bit of a letdown seeing how much he paid for the phones.

 

[Ypoknons]

Let me know if you want to say hi shigzeo heh.