[Kamakahah]

Went ahead and backed the geek wave. Too bad I won't have it to try with the 850s for almost a whole year. Thought it would be one of those fun, " oh, I forgot about that" surprises.

 

[Exesteils]

Went ahead and backed the geek wave. Too bad I won't have it to try with the 850s for almost a whole year. Thought it would be one of those fun, " oh, I forgot about that" surprises.

Backed the Geek Force special. I figured it should enough for a up and about DAP. Now to find one to tide me over till then.. Maybe the DX90

 

[Leo888]

Honestly, get them. I've yet to find anyone who's regretted it. These things are the best $300 I've ever spent on audio, don't think I'll be purchasing any new iems for awhile. Looking towards DAPs these days.

Hi Exesteils, are you referring to the 850. If so, yes it's in my house haha. Sorry that I didn't phrase my post properly but was referring to the Fiio replacement cable.

And yes, 850 is definitely one of my best buy for me.

 

[jborame]

waiting for these to be sold for ~300 again it's killing me.. lol. Anyone here have these and the h-300? If you could only have one of them, which would it be?

 

[Dsnuts]

Went ahead and backed the geek wave. Too bad I won't have it to try with the 850s for almost a whole year. Thought it would be one of those fun, " oh, I forgot about that" surprises.

I got one too. Love my Geek out 450. If the wave sound anything like the Geek Out 450. For $200 I payed that is going to be one heck of a player.

 

[Kamakahah]

Time build a cable for these. They deserve it. Debating between the 7N SPC from PlusSound I have on hand or ordering Toxic cables silver.

Anyone else build their own yet?

 

[Tympan]

 7N SPC from PlusSound

Anyone else build their own yet?

 
Go for it, worth trying. If it doesn't work for you, you can always convert this cable into something else later and spend money on a different cable. 
I made my own cable with left over blue cardas from a previous project, removed the extra weight/bulk (blue insolation, wire shielding, and shrink tubing) and it works like a charm. Super happy with the improvements all across the board.
 
Soldering the cables to MMCX connectors is very delicate as they are tiny and not much surface to solder to. I'd add superglue in the casing before you close it back on them to secure the cables...

 

[SilverTH]

Just receive my fx850! Now I understand what "timbre" means...fx850 timbre is really amazing! Also the soundstage is really big, instrumentals separate is wow!! The more I listen to this, the more I like it! (My previous iem is Shure se215LTD) Also the mid of fx850 is as sweet as se215!
Thank you all people here for showing me how great fx850 does! And thanks to Dsnuts for burn in guide!

 

[wanderer2014]

Just receive my fx850! Now I understand what "timbre" means...fx850 timbre is really amazing! Also the soundstage is really big, instrumentals separate is wow!! The more I listen to this, the more I like it! (My previous iem is Shure se215LTD) Also the mid of fx850 is as sweet as se215!
Thank you all people here for showing me how great fx850 does! And thanks to Dsnuts for burn in guide!

Aye, the soundstage is one of the strengths of the FX850. Sounds very wide for an iem.
 
I must thank Dsnuts too for his recommendation.
 
I must clarify though, the burn-in should be done by actually listening to the iem. It will do nothing if you just leave it on all day and not listen to it. As a senior engineering student with some training in material science, I can tell you that for the sound signature of the driver to change, the material properties/structure has to alter quite a lot for that to happen. And that's big no-no in engineering, that is, a sound driver that changes its properties/specifications after mere hundreds of hours of usage. You guys can find articles online that measure the frequency response changes of iems/headphones before and after hundreds of hours of usage. There simply is no changes between the two states.
 
I personally experienced much tamer bass now in the fx850 compared to before, similar to the tamed down of sibilance in some other iems I've owned in the past. This is mostly due to the psychological effect, rather than the physical one. This phenomenon is also common among hearing aid and hearing implants patients.
 
Conclusion: your brain adapted to new sound of your device. The iems themselves did not change at all.

 

[wanderer2014]

After all these hours listening to the fx850's, I'm quite happy with them.
 
It seems like the consensus on the sound signature of the fx850 on this forum match quite close with actual listening experience.
 
One note about the treble of the fx850: it is competent, extends quite well with all the sparks and shimmer, but quite rolled off. I guess this is to combat fatigue during long listening session. When comparing with the ATH-M50, it's clear that the M50 has more shimmer and sparkle and as result sound more energetic at the top ends. Personally, prefer the way the fx850 sounds, though I do sometimes miss that nice and crisp treble offered by the M50. For people who loves energetic high range, the fx850 might not satisfy them.
 
It is quite interesting to see that for a 300+ iem, JVC opted to go with a more consumer/fun oriented sound signature (big bass, somewhat neutral mid and rolled of treble) instead of the more neutral, analytical and clinical signatures found in other well know audiophile iems (GR07, RE400, EX1000...).

 

[Wnuwk Siphon]

 

[Kamakahah]

I personally don't find much comparison to be made to the M50. I own both and it's like comparing apples to a hamburger.
That said, I agree with most of your statements. I'm also a man of science and agree with your statements on burn in for the most part. Unfortunately, I've had multiple hands on experiences were that same logic simply didn't pan out. One of those was very recent.
I listened to the IEM out of the box for 20 minutes and really didn't like the sound. During that time I checked for a proper seal and connections. After 5 hours of burn in with no listen, I revisited them again listening to the same order of songs with the same setup and there was significant change. So either my brain adapted while I wasn't listening, or something is happening.
I have a number of ideas why that might occur, but that's for the sound science thread. I'll simply leave it at I've experimented with this multiple times with similar results to varying levels. I much prefer quantitative data to qualitative, but the most important lesson in science is that all current understanding can and likely will change.
Every time our scientific community declares to be at the pinnacle of knowledge, something new comes and shows us just how wrong we are and how little we know. I experience that often in my lab. I still openly welcome a link to an actual peer-reviewed journal article.

 

[Ivabign]

  Aye, the soundstage is one of the strengths of the FX850. Sounds very wide for an iem.
 
I must thank Dsnuts too for his recommendation.
 
I must clarify though, the burn-in should be done by actually listening to the iem. It will do nothing if you just leave it on all day and not listen to it. As a senior engineering student with some training in material science, I can tell you that for the sound signature of the driver to change, the material properties/structure has to alter quite a lot for that to happen. And that's big no-no in engineering, that is, a sound driver that changes its properties/specifications after mere hundreds of hours of usage. You guys can find articles online that measure the frequency response changes of iems/headphones before and after hundreds of hours of usage. There simply is no changes between the two states.
 
I personally experienced much tamer bass now in the fx850 compared to before, similar to the tamed down of sibilance in some other iems I've owned in the past. This is mostly due to the psychological effect, rather than the physical one. This phenomenon is also common among hearing aid and hearing implants patients.
 
Conclusion: your brain adapted to new sound of your device. The iems themselves did not change at all.

The gauntlet you have just laid down truly belongs in the "Sound Science" threads - hence the popcorn above....
 
But let me make one point... this is a receipt for 2 pair of IE8's (I used to buy two of things, partly for backup, partly because I'm insane)
 

 
After the first pair had 300 hours or so - I broke out the new pair  - I could tell the difference without fail - even my son did a blind test with me... and after the second set had 150-200 hours (my son took them (and lost them) it was nigh impossible to tell them apart.
 
The difference isn't so massive that you think it is a different can - but there is a definite audible difference once the driver gets settled in....
 
Just FYI IMHO BYOB EOABF

 

[wanderer2014]

I still openly welcome a link to an actual peer-reviewed journal article.

Man, that would be an interesting read. Though I doubt they'd care enough to spend any money on it. The topic of burn-in is not exactly invigorating among the scientific community.
 
For a 300$ iem, and being the large engineering firm JVC is, they'd have engineers responsible for testing the durability of these FX850s. You bet they gotta make sure that their driver designs must maintain the specs for so many thousands to dozens of thousands of hours of usage. JVC might already have the answer how these iems changes after use. And the answer might be the unexciting one.
 
The point is, the FX850 is quite great. Buy it if you think the sound signature is for you. Put it on. Forget everything else. Enjoy.
And I appreciate the feedback from you guys.

 

[Dsnuts]

Glad everyone is loving them FX850s.. You know these might be more closer to a consumer sound but it is a damn good one. Love that treble, love them mids, love that bass, Absolutely love that stage.  A phone that just let you enjoy your music is all good in my book.