[jelt2359]

No, different drivers, Fx750s driver is slightly smaller, fX750 has better bass but worse treble. Think it's easier to tame the treble...but don't have them in hand anymore.

I also preferred the FX750s housing size in comparison.

Ah yes I remember that now. Thank you!

 

[james444]

FX750 already has much tighter bass than the FX850 and sounds more natural as its more subbass focused. Only problem is its peakier treble but maybe some foam and triflanges will help, too bad I didn't make enough time to try.

Tried the back mod on the Fx750?

No, different drivers, Fx750s driver is slightly smaller, fX750 has better bass but worse treble. Think it's easier to tame the treble...but don't have them in hand anymore.

I also preferred the FX750s housing size in comparison.

 
No, I haven't tried to mod the FX750 yet. The difference between the FX850 and FX750 is small, but my friends and I all ended up slightly preferring the FX850 over the FX750 in direct A/B.
 
Just to give a perspective, the impact of these mods on bass performance is much more significant imo than the slight difference in stock bass between the FX850 and FX750.

 

[james444]

Think it's easier to tame the treble...but don't have them in hand anymore.

 
I've tried that on the FX850 to bring treble closer to the smoother sounding FX1100.
 
Sadly, the usual tricks (teabag, alcohol swab, ...) don't give me satisfactory results, as they change the mids as well... and not for the better.

 

[Inks]

   
No, I haven't tried to mod the FX750 yet. The difference between the FX850 and FX750 is small, but my friends and I all ended up slightly preferring the FX850 over the FX750 in direct A/B.
 
Just to give a perspective, the impact of these mods on bass performance is much more significant imo than the slight difference in stock bass between the FX850 and FX750.

 
In stock form I would prefer the 850 to 750. I think the 750 has to be used with long tips, to tame it's treble as that's where the problem lies, damper doesn't do much. Bass can't sound as clean on the 850 as the 750, IME. 

 

[waynes world]

Subbed. Interested in the 750's. Surprised to see treble issues as per inks.

Edit: sorry, I thought this was the 750 thread.

 

[Currawong]

@Inks I reckon you need to post more impressions about products that include, specifically, the music you listen to and how loud. Anything like "treble issues" are going to be related to the music.

 

[Inks]

  @Inks I reckon you need to post more impressions about products that include, specifically, the music you listen to and how loud. Anything like "treble issues" are going to be related to the music.

nobody specifies such things all the time. I don't have a decibel meter to show exactly how loud I listen and I listen to pretty much every genre. 
 
The latter has some truth, older recordings are more forgiving, but regardless the FX750 definitely have a peaky treble, the 850 less so, but it shows with something smoother that yet, has good treble presence. 
 
edit: FX850's treble is at most, a bit peaky, the FX750's is at the very least moderately peaky. 

 

[Currawong]

 

  @Inks I reckon you need to post more impressions about products that include, specifically, the music you listen to and how loud. Anything like "treble issues" are going to be related to the music.

nobody specifies such things. I don't have a decibel meter to show exactly how loud I listen and I listen to pretty much every genre. 
 
The latter has some truth, older recordings are more forgiving, but regardless the FX750 definitely have a peaky treble, the 850 less so, but it shows with something smoother that yet, has good treble presence.

 
That "nobody specifies such things" is the very problem. I've had plenty of headphones and IEMs through here that were great with some genres and terrible with others because, in many cases, the treble in the music being strong which, with the treble peak in the FR of the headphones made them unpleasant to listen with. For "how loud" generally should be OK, eg: quietly, moderate volume or loud. Since you're making a huge effort as a prolific listener, please do so make a huge effort to make better than extremely generalised comments. 

 

[Inks]

   
That "nobody specifies such things" is the very problem. I've had plenty of headphones and IEMs through here that were great with some genres and terrible with others because, in many cases, the treble in the music being strong which, with the treble peak in the FR of the headphones made them unpleasant to listen with. For "how loud" generally should be OK, eg: quietly, moderate volume or loud. Since you're making a huge effort as a prolific listener, please do so make a huge effort to make better than extremely generalised comments. 

That's exactly what I said. I do think that the FX850 is peaky enough to be pretty well rounded in treble and somewhat be desirable to have in some occassions, whereas the FX750 just isn't smooth enough to be as well rounded. Regardless of the genres, a good IEM should be well-rounded IMO and that means not peaky, so to not have treble issues with certain recordings. You can excuse the FX750 with a tame recording and low volume, but that just hides it's flaw. You can do meelec triflanges, which generally do a good job of taming the treble, but I honestly can't say if it's enough for me, because I didn't get a chance to use them 
 
You can always EQ which I like to do with these wood series. Better to have peaky treble that you can tame, than an IEM that lack treble and can't have the energy and extension no matter the EQ. 

 

[james444]

  No, I haven't tried to mod the FX750 yet. The difference between the FX850 and FX750 is small, but my friends and I all ended up slightly preferring the FX850 over the FX750 in direct A/B.
 
Just to give a perspective, the impact of these mods on bass performance is much more significant imo than the slight difference in stock bass between the FX850 and FX750.

 
Today I tried the j444 mod v2 on the FX750:
 
Interestingly, the back-mod doesn't do much on them, which suggests that the stock FX750 have already more rear-damping with less airflow than the stock FX850 and FX1100. I recommend skipping the back-mod on the FX750 altogether.
 
However, the front-mod does a great job of attenuating bass impact, so I recommend performing just the front-mod on the FX750.
 
Listening to the modded FX750/850/1100 side by side, I feel like the FX850/1100's larger drivers sound noticeably better (more detailed / refined) overall. Their advantage in sound quality over the FX750 strikes me as more pronounced on the modded phones than when comparing all three IEMs in stock form.

 

[windwolf447]

Hey James! I like the idea of your mod, but I don't why it is really hard for me to put the straw into the gap, so eventually I came with this idea: use eartips with hole that is smaller then the circle on the back of 1200/850,cut off the tube of the eartips, flip them inside out and put them on the 1200/850. This method works great! Now my FX1200 sounds more balance and a little bit more clearer. And it is extremely easy to switch between mod/normal sound just by putting the eartips on/off. Thanks for your idea!
 
PS: using black eartips might looks better LOL
 

 

 

[james444]

  Hey James! I like the idea of your mod, but I don't why it is really hard for me to put the straw into the gap, so eventually I came with this idea: use eartips with hole that is smaller then the circle on the back of 1200/850,cut off the tube of the eartips, flip them inside out and put them on the 1200/850. This method works great! Now my FX1200 sounds more balance and a little bit more clearer. And it is extremely easy to switch between mod/normal sound just by putting the eartips on/off. Thanks for your idea!
 
PS: using black eartips might looks better LOL

 
You're welcome! I agree, putting the straw into the gap isn't easy and you need good eyes and a steady hand for it. Btw, it's a lot easier if you have a magnifier lamp.
 
The mod you describe is very similar to the one I used to find out how much damping is required (see below). If you put some high density foam underneath that eartip, you'll likely get even better balance and clarity.
 
Let's just say though, from an esthetical point of view, I prefer the straw mod by quite some margin. 

 

 
Here's what I tried today, I donated two small hybrid tips to science tinkering, basically ripped their stem off in order to build some "panties" for the FX1100's backside. Stuffing these "panties" with foam of varying density and listening to the changes in sound turned out to be quite an interesting experiment. Higher foam density means more resistance to the driver's rear side, and as a result mid-upper bass levels and warmth decrease and overall sound signature becomes significantly clearer. My personal "optimum" signature required pretty high density foam, which almost amounts to blocking of the rear vent.
 

 
Unsolicited and amateurish 2c on tuning changes vs. the FX850: it's impossible for my ears to detect whether this is might be a new driver variant. But I'd guess that JVC revised the front side damping to add refinement in the upper mids and highs. Sound quality in this range is a sizable step up from the FX850 and particularly noticeable after attenuation of the bass range. However, I'll go out on a limb and say they didn't change much (or anything) about rear airflow. Whether or not this was an intentional tuning choice, or if they just didn't care for increased bass warmth over the older model can only be speculated upon... but my test result suggests that the FX1100's clarity and tonal balance benefit a lot from added back side damping.

 

[james444]

Seems like the j444 mod has become quite popular and I'm getting frequent questions on where to find instructions, so I've added a link to my signature.
 
Clicking on that link will take you to the original post.

 

 

[Painful Chafe]

  Seems like the j444 mod has become quite popular and I'm getting frequent questions on where to find instructions, so I've added a link to my signature.
 
Clicking on that link will take you to the original post.

 

I'm going to give it a shot this weekend. I have high hopes since I loves the 850's but the bass is a tiny bit distracting at best and with some recordings, and at times a little obnoxious. Does the back mod change the width of the sound stage at all. I'd hate to loose that, but haven't heard any complaints from those who have tried it.

 

[james444]

  I'm going to give it a shot this weekend. I have high hopes since I loves the 850's but the bass is a tiny bit distracting at best and with some recordings, and at times a little obnoxious. Does the back mod change the width of the sound stage at all. I'd hate to loose that, but haven't heard any complaints from those who have tried it.

 
I don't think it changes it. I've mostly used them with front-mod and now with both mods, so I have least experience with back-mod only.