In-Ear Fidelity

Drop + JVC HA-FDX1: “Unboxing”

Closer look at the nozzle's damping material
My favourite combo: blue filters


Now I could give you a long-winded rundown of the HA-FD01 and its significance, but Drop already did my job for me so give them a little traffic.

Basically, the FD01 was an IEM that SuperBestAudioFriends user james444 discovered had some untapped potential within it, with the proper damping and tuning performed. It was subsequently picked up by other prominent members, and now it seems that it’s good enough for Drop to convince JVC to mass produce at a commercial scale. What a jump.

Now, the FD01 I heard was actually noticeably peakier than the “stock” FDX1 (which is supposed to be the same as a regular FD01) so I’m not sure if my personal experiences translate 1-to-1 with everyone else’s. I thought the FD01 was extremely bright, extremely peaky, beyond sibilant and worst of all: had a metallic timbre that made nearly everything sound unnatural. Now at that point I already knew of james444’s efforts and success in modifying the FD01, but I was listening to a store demo unit anyways so I wasn’t at liberty to do any sort of tinkering.

With the FDX1 also comes my opportunity to test out what is one of SBAF’s most critically acclaimed transducer modifications. I’m certainly excited.

Product page:

MSRP: $280 ($250 for pre-sale)

Driver configuration: single DD


My unboxing posts are pretty much the only times I’ll ever talk about build quality, accessories and the like. I’m not really the person to ask about these things as I don’t really care about them that much.

Part of the reason why I quoted “unboxing” is because the FDX1 I received was flat-packed in a simple cardboard box with minimal accessories. I’m not sure if this is the final packaging, so take these with a grain of salt.

Accessories: spiral dot tips, cable, hard case & filters.

Cable: single-wire flat (oblong?) cable. Rubbery feel and picks up a lot of microphonics.

Connection: MMCX. Feels pretty secure, properly set.

Build: housing is almost all metal, including the filters. Looks like it can withstand a lot of abuse but only time with tell.

Fit: designed to be worn straight-down but has a lot of microphonics this way. Swapping the channels allows it to be worn over-the-ear style but it has very little points of contact for my ear size, so it doesn’t feel as secure as I’d like it to be.

Isolation: not very good. Will not use outdoors.

Initial impressions

  • Stock filter is very upper-midrange forward but nowhere near as intense as the FD01 that I listened to.
  • Personal favourite: blue filter. It’s also the closest to my neutral target curve.
  • Very clean and well-defined notes. No smearing or veil going on here.
  • Sharp attack along with a decay that sounds shorter than most DDs, though still more natural than the standard BA IEM.
  • Filters don’t seem to hamper technicalities and only serves to shape the FR to be more pleasant.
  • Bass response is very well-extended and doesn’t lack impact despite its relatively subdued decay down-low.
  • Treble carries a decent amount of energy (blue filters) and nowhere close to sibilance.
  • A pretty good “technical DD” that I haven’t seen since the MDR7550/EX800ST (and one other that I haven’t formally unboxed yet, but that’s for another time).


Due to the number of graphs available, I won’t be attaching them here. Visit the dedicated graph page instead:

Comparison courtesy of the Graph Comparison Tool

My usual thanks to all my supporters on Patreon. And of course shoutouts to my big money boys: “McMadface”, Denis, Nicholas, “caravan” and Justin. 

3 thoughts on “Drop + JVC HA-FDX1: “Unboxing””

  1. Hi Crinicle, recently I could listen to the Sony IER-Z1R, and IT sounded perfect to me… Sadly it is out of reach now 🙁 Does the HA-FDX1 sound similar to that? I have also read good things about the obravo cupid and the Flare Audio Pro HD2. Did you listen to these, how do they compare? Do you suggest the HA-FDX1 also for bass heavy progressive electronic music? Sorry for the massive amount of questions, but you made me interested in the HA-FDX1 with your impressions ☺️ thx a lot Lacas

  2. Curious on sound stage and if bass can be EQ’d up. I have the Z5 and love them except for that loose left mmcx. Given your comparison to ex800, I am curious how that relates in terms of stage and bass ability.

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