JVC FDX1: Questions & Answers
Disclaimer: The modded JVC FD01, on which these new FDX1 are based, have been my favorite IEMs for more than a year now. No one should assume, that this is in any way, shape or form, an unbiased Q&A.
What’s your background with IEMs?
I’ve been an avid IEM collector for many years. In the heyday of my collector’s passion, I must have owned well over a hundred IEMs (I stopped counting at some point). I’ve since downsized my collection, but kept the ones I consider „essential“. That’s why I still have classics like the ER4S, EX1000 or UERM and can directly compare them with more recent IEMs.
I read you’re a fan of dynamic drivers?
Yup. While I have all sorts of technologically different IEMs in my collection, my preference has slowly, but steadily been shifting towards single DDs over the years . The reason for that isn’t easy to explain and I believe there’s quite a bit of „gut feeling“ involved.
Here’s one post, in which I tried to shed a little light on this topic:
„Well, the short answer is, that while I think that (multi-)BAs sound usually clearer and more resolving than DDs, I also think that the timbre of acoustic instruments tends to sound somewhat more artificial on BAs, when compared to DDs or live acoustic music.
To borrow a metaphor from photography: BA timbre reminds me of a slightly over-sharpened picture. Impressive, contrasty and eye-popping, but not necessarily all that realistic.
Still, note that this is first and foremost just a personal opinion. I arrived at it after years of listening to classical music with many different IEMs... DDs, BAs and Hybrids. And noticing a few things in the process: for instance, that I intuitively and predominantly would pick DDs for classical, whenever I had several different IEMs at hand. And that upon switching from DDs to BAs, I would always need some time to adjust to BA timbre. Whereas the adjustment would happen almost instantly, when switching the other way round from BAs to DDs.
Subjective anecdotal evidence, of course. However, it made me stop buying BAs some time ago, since I listen a lot to classical and found myself not using them much. I still like to audition BAs though, and find many of them (like the Andros and PP8) technically very impressive.
There are likely also several scientific aspects relevant to the perception of BAs vs. DDs, like differences in transient response, the amount of odd order distortion, or potential phase issues with crossovers. But that's a multi-faceted and very complex subject, that I still don't know enough about to make any bold claims.“
Another aspect not mentioned here, I think we’re just used to the sound characteristics of moving coil transducers. And that could very well be the reason why many regard them as more „natural“ than other driver types. Think about it, most home speakers and headphones are based on moving coil. And most recorded music is mixed and mastered with moving coil monitoring equipment. So, if you want to hear things „like the artist intended“, what would be more natural than choosing moving coil (DD) IEMs over others for music reproduction?
And you’re obsessively modding these DD IEMs?
I hope not obsessively so. But when I hear something like the stock FD01s, which sound 90% close to my idea of perfect, then I can’t help but try to go the extra mile.
That’s how the FD01 filter mod originated, and after some trial and error, I settled on those alcohol swabs as DIY-filters. Some of my best audio friends took up the mod suggestion and liked it. Well, and the rest is (audio community) history, a story that
@shotgunshane has already, very eloquently, told in
his review.
Ok, so the modded FD01 (and the FDX1) are "perfect" now?
Not quite. As always, the „extra mile“ turned out longer than expected. And like all IEMs, the JVCs come with compromises of some sort. There‘s still a bit too much upper mids boost over what I‘d call perfect. And bass falls just a tad short of the EX1000, which still have the best bass of all DDs I’ve heard. But overall, the FDX1 come very close to my ideal sound signature and are my favorite DDs out of those I’ve heard. Personally, I prefer them over some much more expensive DDs, like the Vega, Xelento and IE800S.
Back to the filters, what’s the deal with that hole in the middle?
Well, it’s there for a reason. In my modding experiments, I noticed that if dampers occupy the entire nozzle, they cause a slight loss of bass clarity and dynamics. Therefore I tried these tube-shaped dampers, and found they do the job just as well, but without that negative side-effect in bass .
How would you describe the sound signatures of all three filters?
First of all, the three filters differ only in upper mids and treble. But since we perceive sound signatures as a whole, the FDX1 also seem to get a bit warmer and bassier as you move from the white to the green and the blue nozzles.
The white nozzles have no damper and hence sound leanest in bass and most forward in upper mids and treble. They create an impression of very high resolution, but that’s partly due to what I call „fake detail“ (an overemphasis on high frequencies). They can also sound quite fatiguing with music that has a lot of energy in the boosted range, like the brass section of a classical orchestra in full blast. However, for low volume listening at nighttime, they may still prove useful. And last not least, they can easily be modded with DIY-filters if desired.
The green nozzles have been tuned after my recommendation for FD01 „reference filters“. I would describe the sound signature as well-balanced, with a tasteful slight bass lift and a touch of warmth. The mids are mostly neutral with a moderate upper mids bump. And treble is smooth, free of sibilance and non-fatiguing, but with good presence and extension. There’s no „fake detail“ with these nozzles, just very good clarity and resolution throughout the full spectrum. These are the most versatile nozzles in my book, and they sound excellent with a wide range of music.
The blue nozzles are just a smidgen more pushed down in the highs and sound more relaxed than the green ones, while clarity and detail remain almost the same. They're the most warm-ish and laid-back sounding nozzles, and also my favorites for outdoors, where a slight tilt towards the low end comes in handy.
But Head-Fi’s measurements show the white (empty) nozzle actually closer to their target than your „reference“ filters?
Yes, I’ve
seen that. What can I say... with regards to upper mids and lower treble, I’d call that target into question. Most people who’ve heard the stock FD01 (or empty nozzle FDX1) would agree that upper mids are clearly too much forward. And that we really don’t need even more low treble in the sibilance range, like the Harman IE Target would suggest.
But in the end, FDX1 buyers will get three different pairs of nozzles and will just use the ones they like best. So, regardless of whether they prefer the Harman IE Target or a more downsloping signature in the high range, the FDX1 will come with a matching nozzle for them.
How about bass? Is it really better on the FDX1?
That’s a tough one. I’ve spent hours A/B comparing the FDX1 to the modded FD01, but without reaching a solid conclusion. However, the majority of experienced listeners who heard both, confirm tighter bass on the FDX1. And there are burst and impulse measurements that seem to back their assessment. Therefore I tend to agree with the majority, even though I personally didn't really catch a significant difference.
So, what’s your advice to current FD01/FD02 owners? Are the FDX1 a worthy upgrade?
Another tough question. It’s actually easier for me to answer that for FD02 owners, since you'd get a better cable and the option to swap nozzles. Plus, the micropore tape mod on the FD02 is less robust than the filter mod on the FD01, so the JVC-made filters on the FDX1 would be a more substantial upgrade in robustness for FD02 owners.
For owners of properly modded FD01s, the upgrade would obviously be a less significant one. Needless to say, the professional JVC-filters have excellent channel matching and could improve imaging compared to DIY-filters... particularly, if you don't have a measurement rig to ensure consistency of your work. As for bass... I’d probably say that those, who‘re satisfied with bass quality on their FD01, don’t have much reason to upgrade to the FDX1. But for those, who feel that bass sounds a little too loose on their FD01, the FDX1 might well be worth a try.
I’ve been thinking about buying and modding the FD01. Should I go for the FDX1 instead?
Are you kidding me? Why would anyone buy and mod the FD01 any more, if they can have the professionally damped FDX1 for less money instead? Thanks to
@shotgunshane,
@CEE TEE and the team, the FD01 filter mod should be pretty much obsolete by 9/5/2019!
