Fiio FD15 Impressions

I have a fiio FD-15 on order. I will give my impressions over time. I hope this information/thread will be helpful.


Had the FIIO FD15 for two days now, together with the cheap JA11 dongle.

I quite like the FD15, you get good accessories(except storage box), many tips, good modular cable and the build quality is nice.

Natural sounding DD, sort of smooth sound. Technicalities allright, nothing remarkable but nothing wrong either.

Bass is deep and have good texture, but lack some in quantity. But ofc this also make the IEM be more neutral.

Very well done midrange that is never shouty or sibilant, would say it’s mid forward.

Highs have decent sparkle and air, not dark and not bright.


I received my FD15 set a few hours ago. I have been listening off and on and using other IEMs as ear/hearing “washes”. Initial impressions are quite positive. I am using the eartips that are on the IEMs in the box. I love the cable. Very comfy.

Fit is nice. The earpieces weigh a bit. I have no issues. Others may need to note there is heft present. the nozzle angle is flawless for my ears.

I am running the FD15 in SE into the L&P W1 from iPhone 15 Pro with Apple Music. I seem to be getting some burn-in effect as transients are improving. They were somewhat blunted in the upper mids and lower treble originally.

There seems to be quite varying opinions/reviews on the iNtERneT regarding the FD15. I am not getting @Timmy-Gizaudio’s claim of “honkiness” in any way, shape, or form. Maybe that may arise with burn-in? I also don’t see it as a “warm-neutral” set as some others claim. I don’t hear it as a technical set as one reviewer mentions elsewhere. Again, maybe burn-in will change the DD over time. I DO see this as a set with mid and sub-bass being present but mid-bass is the clear favorite. Bass guitar and acoustic kick drums, rejoice! Really good stuff. This is a mid-bass head’s IEM. Sub-bass heads, well, look elsewhere. The mids have good weight without being too bloated. There is less mid snap than is my ideal (Kato). Mids are competent. But, I prefer Moondrop’s VDSF usually. So, take my impression with that in mind. I can’t hear past 10 kHz, so I cannot comment on treble extension. Treble is competent.

Soundstage has decent width. Not as expansive as the Hana 2021 or as tight as the Kato. Instrument separation seems to strike a nice balance between contrast and irritation. I would say it is too early to judge dynamics. From other headphone and IEM sets (including comparing some well-settled sets with new sets in direct A/B comparisons over days) and my experience with scores of guitar and bass cabinets, for most drivers, dynamics do not truly settle for a while. The outlier Hana 2021 took 30 minutes max to settle.

My impressions may change over time as I explore other ranges of my library and the driver matures and I tip roll and attempt balanced mode and different dongles. As it stands right now, FiiO has a very competitive set in the price range.

add: Birdland by Weather Report is rendered quite well by the FD15


Tried it yesterday. It was pretty fun. Whatever they are doing to increase the bass reverb is affecting the upper frequencies as well. It may be a good thing though as all transients have strong attack but soft peak and slightly longer decay then what Im used to on the FD7. Reminds me of a analog verson of the super slow roll off filter. Makes it easy to listen to even at high volumes.

Other than that one nitpik its a really nice sound. Makes vocals sound mesmerizing and romantic. Pretty fun sound. Particularly with female vocals from Kokia and kalafina. It has has this good haze such that you dont feel it in your throat but eveything is still well defined.

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I had an hour or so to listen again. I did find a female vocalist that sounded boxy: Sheena Ringo in Utada Hikaru’s Nijikan Dake No Vacance. Most female vocalists do not have any boxiness, to my ears. Examples:

Born to Die by Lana DelRay
The Barrel by Aldous Harding
Online Love by Uchu Nekeko
The Thrill is Gone by BB King and Tracy Chapman
Ikiterudakede Eraiyo by ReoNa
My Pal Foot Foot by The Shaggs
Suzume by Radwimps featuring Toaka
Addiction by Hitsujibungaku
Aino Shirushi by PUFFY

I still wish for a little more at 3 kHz. I want my VDSF for female vocals. lol

Not to start a stream war, but I noticed that the FD15 sounds much better on Apple Music than Spotify for the same exact song. I found more than a few tunes where the boxiness popped its head on Spotify but not on the Apple Music version:

Tenderness by General Public
My Ever Changing Moods by The Style Council
Cocaine by Eric Clapton
Train in Vain by The Clash

@lysender, I am not picking up the bass reverb you mention. Can you give me some example tracks to listen to? Though I am not a full fan of metal, I think the FD15 can handle the bass/drums in This Fire by Killswitch Engage and the Devil in I by Slipknot with proper decay. I am using the silver tube and the semi-transparent tips on the FD15.

Highlight band for the FD15: The Smiths.

Your impression is kind of in line with Timmy’s. How’s the Ja11 though? I ordered one because of the parametric EQ support feature.

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@HTT No worries if you cant detect the extended decay, its just a minnor nitpick when directly comparing to the FD7/ibasso 3t-154.

Kokia-the Cell
Mostly its how her vocals get slightly blended that makes for alot of the minnor nuances like the curls between breaths being lost.

Massive new krew-into the sea of stars
The timing really trew me off there. Everything has this reverby texture to to it. Everything in the song is quite tight and there are quite abit of triangle wave sustains.

Will be back later.

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It will take me a couple days to listen and respond. Busy time at work and home.

JA11 is decent, not at the level of the best dongles ofc. But more than worth it price, the one I recommend forward for people who need something small on the go.

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Starting my review today on FD15, I think the decay you are talking about is how the transients are a little smoother on every note.
This softens the music and make it more organic, but in return you loose some cleanliness and the sound is less resolving.

As for decay itself it’s neither slow or fast.

Of course I can be wrong and you hear something totally different.

Hi Leonard,
Possibility of comparing it with FD5?

Sorry don’t own that one, only had 2 FIIO Iems prior to this. And they are old stuff

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Yes that is what I am refering to. Thank you for putting it so susinctly.

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I had a chance to listen. Yes, I do hear what you are saying about the resonances (decay/reverb tail) . But I notice it most in the mids. I did an A/B against the Kato. The Kato did not have the issues you pointed out about the FD15 with the two songs you suggested.

OTOH, with the following song, the Kato seems to have issues in the mids with resonances but the FD15 is much tamer. I was using Apple Music Hi-Res Spatial Audio via iPhone 15 Pro>L&P W1>Kato using Azla Xelastec/vs FD15 using black nozzle and “balanced” fiiO tips both sets in balanced mode at a mean SPL of 78 dB.

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I notice small burn-in effects, after about 20 hours of total use of the FD15 with breaks and listening to other equipment as a break. I notice a slight increase in bass elasticity and a slight decrease in some harmonic distortion. Notable, but not some change in frequency response or the IEM is a “whole 'nother level” with the burn-in.

Also, I find that I need to push the volume a slight bit higher than the Kato and Hana 2021 to find the minimum SPL for the “sweet spot”. I normally listen at a mean level of about 72 dB with the Kato and Hana 2021. I need to push the FD15 to 74 dB. The FD15 sounds rather drab and lacks some dynamics when listening below the “sweet spot”.

Yeah pretty decent for the price. Great for on the go.

Was listening again and I think it reminds me alot of horn speakers but with the advantage of being able to play fast passages