Preamble:


I am a grateful participant in the Fiio F9 Pro review tour. So thank you Fiio for providing this opportunity to us head-fiers. Your engagement with the community is outstanding! The review unit was not a “keeper” but had to be shipped on to the next reviewer. I am, however, eligible for a discount on my next Fiio purchase because I pledged to write a review. Fiio insists on honesty, and that’s what you and they will encounter with the below.


I hate to even have to say it, but sound impressions are subjective - and so this review will undoubtedly be subjective. Not only that, but sound can objectively change with things like insertion depth, tip choice, etc. Here’s my usual rant: high frequencies in a small space (and low frequencies in a larger space) will create standing waves. It’s physics and you can’t avoid it. These frequency dips and spikes will present differently based on the volume of air in your ear canal. For this reason, I’m a fan of foam tips as they help decrease these reflections. While the treble is decreased, it is usually more linear with foams. As with all IEMs, I have used genuine comply foam tips (large) for this review.


Also, I’ve exercised great restraint by not subjecting myself to other reviews of this particular model. I have read reviews of the original F9, but not the Pro. Once this is finalized and posted, I’ll have a look at what others thought.


Summary of the Soundscape:


The F9PRO is mildly V shaped: it has good sub bass, is hot in the bass, a tad light in the lower presence, good upper presence region, a tad hot in the sibilance region, with enough in the brilliance region to sound detailed. How’s that for a one line summary?


The pro is what I’d consider a safe sound - it strikes a good balance between consumer and audiophile. There’s enough impact to engage the listener, with enough finess and detail to satiate the audiophile. Detail is respectable and I’m hearing things that I’d not heard on my beloved Zero Audio carbo tenore. I think the BA upgrade has something to do with it. No, they can’t match my JH iems, but with a little more in the top octave, they’d put up a tough fight.


Imaging is excellent, being able to place instruments in the field with accuracy. I’m not getting the three blob separation that is common on many IEMs. The entire field from left to right is filled without gaps yet retains a clear and focused “phantom center”. Tracking instruments that pan from left to right is effortless. High marks for imaging!


I’m not the best judge on soundstage because I don’t really value this attribute in a set of headphones or ‘in ears’ as much as others. I think I’m outside the norm because I actually like the “in head” experience. With that said, there’s still enough width to sound spacious. Nothing jumped out as being out of line with other IEMs, nor was it overly congested. They didn’t sound blown out large/wide, and they didn’t sound one-dimensional in my head.


Setting Up for a Listen:


Unless otherwise noted, I used the AudioQuest Dragonfly Red, fed by an iPod Touch, playing Hifi tidal, and finished with comply foams when I took the notes on treble, mids, and bass. I listen to progressive rock and metal, so there is plenty of “busyness” and lot’s of instrumentation (mostly with vocals) to challenge this IEM.


Normally, I have to endure the torture of sibilance when I use silicone, but these took to the silicone better than other IEMs I’ve used. What I didn’t expect was how well these performed with spinfits and spiral dots. Spins sounded very much like the stock Fiio tips, and the dots sounded a bit more present. Still, I only used the silicone long enough to observe this, then promptly moved to my beloved foams for the fairest impressions (after all, it’s what I’m used to).


I also tend to obsess on treble, not that I’m a “treble head”, rather I’m sensitive to it and gravitate more toward realistic and smooth treble vs impressive or overly sparkly treble. This leads me to be somewhat overly critical of treble, so please keep this in mind as you read the rest of the review. And how fitting that we start with the….


Treble:


Treble is rather pleasant overall. There’s no obtrusive spike that detracts from the music or that focuses excessive attention to it - something I was expecting given the graph of the F9 original version. I do sense a rise nearing 10k however, then the energy falls off quickly afterward; at least it seems that way in comparison to the 10khz region, so some “air” is perceivably missing. Top octave is attenuated by a few db, so the extension is not great. If there was just a few more db between 10 and 15K the treble would be more lauding on my end.


Yet the timbre is rather good. Nothing sounded fake, metallic, or shrill. It was mildly sibilant with some vocals on a few tracks that presumably weren’t mastered well, showing clearly that the engineer opted not to use a de-esser or limiter. I was fearful that consonant S and T sounds would have a consistent “wince factor” to them, based on the original F9 reviews, but I’m not hearing that much at all on the pro version. Sibilance only creeped in once in a while. Keep in mind I’m very critical when it comes to treble (very sensitive to sibilance), and still, I find the treble pleasant.


The 5-7khz region is petty well behaved with only a few areas of heat. This heat gives cymbals more of a fundamental tone (the stick strike is emphasized) vs hearing their overtones shimmering. But it is only a minor lift in this region so it’s not an issue unless you’re listening to music with never ending cymbal crashes, which tend to sit above the mids a bit. At times, the cymbals sound more “cush” than “psst”. Sound that out, and you’ll know what I mean.


The decay here is good. Cymbals don’t ring out to infinity, but the decay is convincing.


Mids:


There is a perceived gap in the low mids - 500 to 1,000hz? Had this been raised, I don’t think there’d be the V shape I attributed to them in my summary. But this slight gap also provides a good deal of separation between the bass and mids, so there isn’t any bloat or intrusion into the very musical presence region.


The mids and high mids are voiced very nicely - but sit behind the bass and treble slightly. The tuning here is very good.


Bass:


Bass is surprisingly deep and only slightly emphasized at 90-180 hz, making for a nice impacting sound.


Bass hits hard. Really, I wasn’t expecting this quantity. Its impact had proper punch without being anywhere near obnoxious and the decay was better than good. Bass didn’t hang around and moved in an out of the scape like a proper dynamic should. It’s not dry and instantaneous like some BAs present so I wouldn’t call it fast bass - but still nimble and authoritative. Being used to BAs, it made me realize I was missing something - something visceral - and the fiio provided that.



Source Matching:


You can tell that Fiio intended this IEM to be paired with their DAPs. On the X5iii some of the low mids were put back in place, improving the coherence and balancing out the overall sound compared to the Dragonfly Red. The synergy with the X5iii is on point. Overall accuracy of timber jumped up a notch compared to the Dragonfly Red.


Moving to my main setup, arcam rhead with iFi micro iDAC2 (my most resolving setup) - The F9 Pro scaled well with better gear revealing a tad more detail and control over the bass. Not that it was flabby to begin with, but what was very slightly rounded bass, now seems a bit more linear. Sub bass and bass became more aligned. They took the juice here admirably - and needed a bit more out of the rhead than I was expecting. I didn’t do any volume matching but can safely say these are not “super easy” to drive and will be served best by a proper amp.


Items to Note:


All of the review notes above were done using large comply foam, with a medium to deep insertion - what I’d consider standard fit. I later found that by using large foam with a shallow insertion was best sound quality for me. Any sibilance was removed, and the top octave appeared to come out some more. Did the heat at 5-7K disappear? No, but it was attenuated in relation to other frequencies. However, for my ears, I just can’t keep them at a shallow depth and move about, lest they break seal. Your ears may be different and you may find the F9P to present as I just described with other tips and methods that work for you.


Phase alignment is good - bass and both BAs working nicely together.


The rigid case stood out as a nice bonus - heavy plastic that is just the right size and incredibly functional.


mmcx connectors are not easy to detach and don’t allow effortless swivel - a good thing! very secure.


Using none other than fiio’s own 2.5mm balanced to 3.5 mm SE adapter cable, my braided cable impressions are that it is better. It seemed to carry the signal with less graininess. This can’t be measured on a FR graph, but that’s what I’m hearing. Anyway, it’s less unruly, looks nicer, feels nicer, tangles less, doesn’t have the mic inline, so it gets my recommendation.


Comfort was outstanding. Although I’d want to see a shirt clip provided (if one isn’t already). None came with my review sample.


The metal housing should provide better than average, if not really good, durability.


Bottom Line


These weren’t the best IEMs I’ve heard. But OTOH, had no fatal flaws. Finally….. they are worth every dollar of their asking price, and then some. To prove it, PM me a few weeks after this post and I’ll show you my receipt, because I will be buying them to add to my small collection.


-Vince

While this is review is in pro-con form only, it is still a very detailed gathering of impressions. It's also necessary to read my preamble to understand why I'm nitpicking these IEMs. I hope my impressions will be helpful for those looking to get into the high end IEM game.

Listening Conditions

This is my first expensive IEM and I'm floored by its performance. I'm not a big fan of soundstage, but am beginning to appreciate it more, as I dive deeper into the music. I'm more concerned with imaging and instrument placement in the stage, not necessarily width. I also didn't appreciate how much a warm and present midrange could add to the emotion of music. Now, I do after having the Angie. I have primarily been hooked on sub bass extension as well as the top octave shimmer above 10K. While that tended to impress technically, the extension is only one aspect of the overall experience and grading of an IEM.

For me, tonality and timbre in the form of FR comes first, followed by attack/decay/imaging (PRaT if you will), then the expansiveness of the stage. Also, everyone's ears are different and while there are objective qualities to a set of IEMs, like PRaT and stage to some extent, some are purely subjective like FR as certain frequencies will be attenuated or amplified based on one's specific ear canal resonances. This is the mission of finding the perfect set of cans/IEMs and the reason why it never really ends! One can easily cycle through thousands of dollars of gear before they find what works best for them.

Realize that I have tip rolled these things to the point I'm concerned the nozzles might break. I've tried spinfits, spiral dots, various other silicones of various sizes placed at various depths (both on the nozzle and in my ear). I am straight up tired of playing with tips. I've also run the gamut of foams - true comply tips as well as some cheaper, but less porous aftermarkets, again, various sizes and depths both on nozzle fit and insertion depth. My goal in finding the right tips was to minimize the treble spikes and provide the most natural and smooth treble.

I finally settled on the less porous (smoother/shinier foam) medium size - placed about halfway onto the nozzle which allows for a deep insertion (see pic)- though I don't force them to couple with the bony part of my canal. The get just deep enough to take up the air volume in my canals without giving me a sensation of being violated. I'd say moderately deep.



I set the bass dial to 1:30 or 2:00 - have been keeping it at 2 recently. Any more and some bleed into the mids happens.

I listen to prog - prog metal and general progressive rock. Mostly all of the albums in my collection have very respectable, if not impeccable production quality.

I’ve been using the balanced cable on a fiio x5 3rd gen - I can’t hear any hiss or noise. Though using the 3.5 single ended cable, I can hear a very low hum - this isn’t the IEM, it’s the x5iii’s amp. I also have been using this with the single ended cable on my home system: Audirvana+ > schiit modi multibit > schiit asgard 2. Again, no hiss or hum here.

Evaluation

Having said all of that. The Angie comes with some tradeoffs, though it is the best I've heard so far. And the tradeoffs are a subjective thing. All the other aspects, make this an excellent IEM:

Pros

-Very emotional, warm vocal timbre and overall mids. Expect a nice warm emphasis on 800 to 1000 hz warmth - makes for a very “moving” experience, engulfing the listener deeper into the music. After I switch to any other IEM, I feel I’m lacking this experience and am left wanting more of the emotion and warmth of the vocal region. This tuning is very appealing to me.

-Excellent presence of vocals/guitars etc (1K to 4K). Electric guitars take the focus in a way that isn't shrieking, but very full and present. This is almost as impressive as the lower midrange warmth.

-Attack and decay is superb - bass strikes, then gets out of the way with no bloom. cymbals do the same, but continue to decay very gently, without being destroyed by other transients - a feature of the 4 armatures dedicated to the highs. Reverb tails here decay with such sweetness - think analogue.

-Natural treble - cymbals sound real and not overly shimmery/harsh - very sweet treble. imaging and instrument placement is impeccable. They cymbals don’t overwhelm the rest of the drum kit - which I really like. You can hear them clearly, but they don’t rob the rest of the music. A bell strike sounds like a bell strike. A splash, crash, ride, hat clap all sound very real and articulate.

-Stage is wider than I'm used to from IEMs - even better than some over-head cans (despite deep insertion) - this is very puzzling to me, but a feat I'm sure others will appreciate. I rather like the change to a wider stage since the imaging doesn't seem to suffer.

-Imaging is top notch - center image is closest I’ve come to sitting in front of studio monitors in a sound treated room where the primary reflection points are controlled. You’ll swear a third IEM is plugged into your forehead. This phantom speaker is a phenomenon only achieved by perfect imaging. I suspect this has something to do with the phase control from the steel waveguides.

-Detail retrieval is the best I've heard so far. I'm hearing transients and utterances that previously went unnoticed. Technically, this is a very impressive IEM. Again, the waveguides may have something to do with this, but the separate armatures themselves, when done right, can achieve the same.

-They are aesthetically gorgeous. It’s hard to beat the kevlar fiber weave under the shiny acrylic finish. The look as good as they sound and impress the lay person who sees them and doesn’t know what they are. The magic inside is ensconced by more magic on the outside.

Cons

-There is some extra heat at 1/3/5/7 Khz that could be smoothed out by a couple dB - especially at 5.3 and 6.9k, these are the two areas that sting a little for me. I have a controllable sine-wave sweeper in my chain that allows me to evaluate spikes/nulls. This extra energy, however, it what pushes detail toward you. When I EQ these to equal loudness, the overall experience becomes a tad more relaxed and easier to listen to, but I miss out on details and the IEM begins to sound like all my other stuff. Hence TRADEOFF.

-Vocal sibilance on poorly recorded/mastered material. This really is a nitpick because I am VERY sensitive to the sibilance region and I don't see others having nearly the same concern with it that I have. The heat at 5 and 7k align perfectly with the voice's "s" and "t" consonants which spike out my ears on occasion. This very rarely happens with instrumental only music, and only sometimes happens with vocals - leading me to believe it's more of a mixing/mastering issue. Combine that with my sensitivity here and I'm inclined to forgive the 5 and 7K peaks. Also, these peaks may just be unique to my ear anatomy and not present the same for others. Still, the peaks are certainly there and at least 6 db above other areas in the upper mids/lower treble. It gives you more detail, but tends to mask the upper octave air at the same time.

-The upper octave extension is there and it's linear to my ears (down sloping from the lower treble region with a slight peak at 12-13k), but sits behind the rest of the presentation, especially the mids/upper mids/lower treble. I can clearly hear up to my limit on these (approx 17k) but they do present gently. I would have preferred the tuning to have a bit more quantity in the top octave - say 3-4 db relative to the high mids and lower treble.

-Similarly, the bass extension is there, but gently rolls down from 50 to 20 hz. This can be changed by altering the bass pot on the inline cable, but when raising the bass on the dial, it also causes a bleed into the mid bass/mids and creates a muddy mess. This is a nitpick

-The cable could be 6 inches longer, allowing for more wearing/routing options. It barely makes it to my pocket where my player lives. This gets even worse if I use a shirt clip to keep it from pulling at my ears. Great cable otherwise!

-The aluminum case is rather small for such a large IEM. It’s hard to get the IEM with the cable into the case without bending the ear hooks or squeezing your foamies.

-Comfort is hit or miss, but we audiophiles like to suffer for our hobby. I was able to get used to them after a couple weeks and can listen for hours without issue now. Because the body of this IEM is so large, it will apply pressure to the various hard cartilage areas of my outer ear. This varies based on insertion depth.

-They are a bit unruly because of their size - the occasional adjustment is necessary for me, but only if I’m on the move. Forget sleeping with them if you lay on your side.

Conclusion

I hope this was helpful for you and your journey. I’m open to personal PMs if you want to know more, or you can post on the Angie impressions thread and I’m likely to respond, though the thread is old now and has seemed to die down.
-Vince

I had the Modi 2 Uber and the Multibit side by side for a couple days hooked up to my Asgard2 feeding Hifiman HE400i cans. I use a Mac running Audirvana+ in Integer Mode and stream 44.1 FLAC from Tidal. I don't upsample/oversample and I don't dither unless I use the software volume (which is like never).

After warming both of the DACs up for 24 hrs and comparing them, I could hear a sweetness to the treble (less splashy and "digital") in the Multibit, along with a fuller mid section and rounder bass. The difference between the two was more apparent than the difference between a good quality 320AAC and 44.1 FLAC file. To my ears, it was a very easily discernible sound depth change, and for the better!

The multibit made it sound as though the music went through some sort of DSP that created sonic layers adding more separation to each instrument, but it sounded more organic than DSP - like it was revealing the source better than the M2U. I'd venture to say anyone with an ear for music and a precursory understanding of frequency response and stereo imaging could hear the differences - provided they could hear up to 16-17Khz as I can. Dare I say it made the digital signal sound more vinyl-like? Yeah, I think I just did and I stand by it.

Now, keep in mind, this was a purely subjective test with no control. I couldn't volume match as the two have different output voltages at the RCA outs. Also, I couldn't do a true A or B = X test because I live alone and most people who know me would laugh hysterically if I asked them to administer such a test (though my neighbors are probably happy that I'm into phones now vs home theater surround, ha).

I've heard many people argue that old school tech R-2R "ladder" DACs aren't any better sounding than a good quality Delta/Sigma DAC and that it is all expectation bias. Maybe that's true of the best quality Delta/Sigma DACs, but I'm comparing these two pieces of Schiit. No perceived increase in sound quality could also be because they aren't feeding their DAC with the best signal possible from their computer. I found that integer mode will make a difference - so will allowing the resistors in a "ladder DAC" to do their thing to the native sample rate and that upsampling/oversampling only confuses the sound.

For me, it's a clear win at $100 more than the modi 2 uber. Even if all of the sound improvements are psychological, I can't say I give a darn, because I sleep better at night with no regrets floating about. That's worth $100 alone. So there.