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
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