FLC Technology FLC 8S

I would've never imagined that my first ever post on this website would be a review of, the now old, FLC 8S, that I've had for years, and just when I'm thinking of buying a new set of different iems.

But I read that Forest Wei visits these forums, so I thought maybe I’d give my 20 cents (yes, not two), so that I have something to look forward to, the next time I plan to buy a new set.

So, let me talk about myself, the earphone and then about a design reconsideration that might help this design get even better.

"Water, water everywhere, not a drop to drink." - "The Rime of the Ancient Mariner" by Samuel Taylor Coleridge.

With 36 different (maybe not so distinct) combinations, it still leaves a standard consumer, "me", wanting more… bass, mids, treble… ok, maybe not mids

I did, before this (and still do), own a TF10. The only way I could even convince myself to buy them for the price, was that I had a few engagements that I had to honor, and I had changed cities and so, couldn't do the acoustics. Now, let me be honest... When I bought those, I didn't suddenly see the light at the end of the tunnel. I was expecting so much more… to be blown over, shocked, surprised… any emotion! But as I mixed my first track... god!!!... just perfect. That was when I realized the kind of gems they are. In time, I was hooked! Never touched an eq… ok maybe a little bass… ok, maybe just a little more…

I could never imagine going to any other; but as luck would have it... one day when changing the complys on them, the front part just popped out. $#@%!

I decided to try something new, and this time, I went through this forum, and bought FLC8S, because I could alter it to my taste.
Shocked, I realized, I couldn't... going through the 36 combinations, I found none that suit my preference.
(I'm not going to spend my time explaining the sound of all the filters (there are enough reviews for that), except tell you how did I get the most out of them)
And then, it happened... so far, I've always been someone who takes things out and puts back in... altering it, even when it's not meant to be altered. That explains blue led (instead of stock green) and custom mesh in front of the tweeters on my Yamaha MSP5A monitors, four three-way switches on my guitar, etc.

I like a fuller sound... very good bass (thumping with good impact) + good body (200-500Hz) that make the male voices sound deep and female voices powerful + corresponding intensity at 500-7K that so that there are enough dynamics, structure, and the sound doesn't feel muddy, and then a slow rise from 7K onwards so that there is a good amount of airiness in the sound... pronounced huskiness in the voice, crisper shimmering of high-hats, etc. Ok, may be a very shallow U.

The closest available combination for this was the red + black + gold filter.

But this still lacked some to the extent I liked... I needed more bass, more body, more shimmer.

So, the first to go, was the LF filter, then the MFHF filter, and then the red came in... or was there already.
Now, it was almost there...
Unfortunately, though this was the closest to what I liked, it brought in distortion… lots of it. The sound started to feel like I was pushing it beyond its limits.

Though the earphones weren't meant for this kind of configuration, I think a change in the design of the ULF (and maybe even the LF) filter could’ve helped in its use as such.

With removal of the LF and MFHF filters, we are letting the diaphragm vibrate freely, instead of giving it resistance to keep it in control, by keeping the two filters in.

This, coupled with the addition of the red filter that doesn't let any air pass through the ULF vent, I think, creates some kind of incorrect pressure chamber; free movement at one end and very strong restriction at the other.

OK, now, what allows the changes in the sub-bass response? The red, black and clear filters, right?
These work on the principle of stopping/resisting the airflow though the ULF chamber. This is not very efficient.

Now, please try this, use my config, pump up the bass a bit, and first try to recreate the issue I face.

Then take the red filters out and tape the hole instead. You'll see that the bass reduces just a little bit (still a lot higher than black filter) but clears up the muddiness a lot.

This happens because although you've closed the hole, you've added a little more breathing space for the diaphragm to move.

I know that the diaphragm was never thought of, to work under these conditions.

The question is, “why?”. Was is not expected that some people would like the bass a lot more. Even if you use red, black and gold filters, this happens if you pump up the entire bass region using an equalizer.

So, a better ULF filter design would've been, maybe a larger hole, and the filters in the form of a ring with a diaphragm made from a balloon-like material with varying tension depending on the bass response required. Higher tension for more bass and lower tension for less bass. This allows the diaphragm to have certain restriction in movement and aid the diaphragm in returning to its original position.



So, I’ve been using these without the LF and MFHF filters, and with a balloon cut-out taped at the hole of the ULF filter.



This brings the bass somewhere between the red and black filters but the distortion has reduced considerably. The distortion is lesser than with black filters and boosted bass. This also seems to reduce the harshness in the sound.

Removal of the LF filter completely has given a fantastic body to the sound, the vocals, lower keys on Pianos LFOs etc. Downside, the sound feels a little closer.



The removal of the MFLF filter has opened up the mids and highs in a way that has flattened the sound out. I miss the airiness of T2s though.



So, there you have it... a few more combinations, beyond the 36.
Should make the 8N more appealing, but you can't go wrong with this one either, especially if it's available for reduced prices.

~::I originally published this on THL. Now I wish to share it with my Head-Fi fellows::~

::Disclaimer::
MusicTeck provided the FLC8s free of charge for the purpose of my honest review, for good or ill.

www.MusicTeck.com
FLC8s on Amazon

MSRP: $355
Hybrid design
2x BA
1X Dynamic Low
Impedance: 11 Ohm
Sensitivity: 93 dB/mW
Frequency Response: 20Hz-20KHz

__________________________________________________________________________________________________________

That stalwart chap Andrew over at MusicTeck emailed me one day and asked if I was interested in reviewing FLC Technology’s flagship IEM, the FLC8s. Understand, this is a famous earphone. It took the community by storm a year or two ago. I did quite a lot of reading on it back then, and even had the briefest listen to a set in a café when I met up with a friend and fellow reviewer in my area.

Naturally, I told Andrew “Yes!”

I like almost everything about the FLC8s.

Beginning with size and shape. These are seriously comfortable IEMs. They are light-weight, and ergonomically righteous. You can insert deep, or shallow, if you have the right size tips. They do not fight you. Wherever your desires lie, the FLC8s will accommodate.

The cable is… okay. It’s light, which is good, but it’s also rather springy, and can get a little out of hand. I would like to see a tamer solution in their next release. This is really just about my only complaint about these earphones, and it’s a minor one, all things considered.

FLC Technology includes a high-endurance, anodized aluminum puck-shaped travel case. I’ve used a number of these over the years, and they work quite well. Very protective.


This IEM can be tuned using swappable parts at three points. Each point has three possible filters. This makes for a tuning variety of 36 distinct signatures. Some of these filters can be tricky to work with, due to their ridiculous small size. Always work on a flat surface, and be ever so careful. Losing one is all too possible.

Now… there’s no way I’m going to describe all 36 signatures. In fact, I have not listened to them all. After reading the manual, I installed Red, Black, Gold. Then, after speaking with a friend, switched to Red, Black, Gunmetal. I have not experimented further. That is the sound I like. It is the most bass-heavy and warmest, despite what the manual claims.

So as you read my sound description, remember, the other filters can give you significantly less bass and more treble, if that’s your thing.

Again, my impression of how the FLC8s sounds is based on the Red, Black, Gunmetal filter setup. For me, the Gold nozzle filter was still a little too bright in the treble, and a friend suggested I try Gunmetal. This sounds just about perfect to my ears, with the biggest bass, warmest mids, and least harsh treble.

The FLC8s is a fundamentally clear, detailed IEM, and with the right filters, counterbalanced for delicious warmth. Tonal richness mingles with transparent, highly articulate rendering. The weight of the notes is on the lighter side, but do not feel hollow. Instead you get a thinner, airier quality. Yet that dynamic bass is ever-present to keep things grounded and deep.

FLC has struck a curious balance between clarity and detail, and a relaxed presentation. It has all the vibrancy of a quick performer, but feels laid-back like a much warmer transducer. Whatever trick they’ve pulled, I approve. These are a very easy listen.

No matter what filter you use, the treble is on the brighter side, and sparkles freely. I find Gunmetal warms it up the most and is quite pleasant to my ears. Using Gold, it was a little fatiguing. Listening to Gunmetal, the highs are well-extended and smooth. There’s quite a lot of air, and light bathes the stage, revealing everything. Symbols and high-hats become prominent in the mix. Textures sharpen into relief. Details galore!

If you want laid-back treble, these are not the IEMs for you. Even with a dynamic driver dedicated to the low-end, the highs are really FLC’s main asset. You can feel the effects on every note, in the transparency and cleanness. The treble is not the finest I’ve ever heard. There is a slight glare, and it will bring out the sibilance if the recording contains any. Indeed, the FLC8s is a revealing monitor.

The mid-range is where that incredible balance shines the brightest. It’s so rich, yet so clear. Honest, beautiful warmth imbues the acoustic guitar, but never at the expense of precision. The intricacies and grain of a vocal piece are showcased in full, all while possessed of subtle lushness.

The romantic notions of the FLC8s are there, though tempered by high levels of technical proficiency. Voices sit large, center stage, with clean boundaries. The empty spaces around, and especially behind the vocals, are filled with a fairly black atmosphere, adding to one’s immersion in the music.

I hear the mids as quite linear and coherent. From male vocals to female, the characteristics are the same: Warm, clear, and extremely detailed. They are powerful and very present, but not shouty or unnatural.

Oh that sweet, sexy dynamic bass. Some people find hybrids a terrible mismatch of tone and quality, but I love them. I have a passion for Balanced Armature IEMs, but a Dynamic Driver delivers a low-end like nothing else in this form factor. Indeed, if you’re using the bassiest filters, the FLC8s is awfully satisfying. It’s not outright bass-heavy, but the lows are emphasized enough to create a thumping, driving force to the music, with great warmth. It’s likely more than some purists want, but as always, there are filters for that.

Sub-bass is raised a bit over mid-bass, and there’s a gradual decline through upper-bass into mid-range. This produces a visceral, rumbling low-end, but one that doesn’t suffer aggressive bloom, and doesn’t bleed into the vocals. It’s tight and controlled, yet mighty as ****. The resolution and texturing of these sub-registers is impressive. FLC generates such a large, deep bass line. Its timbre is fulsome and luscious. In short, I’m a big fan.

Soundstage is not great, but not depressingly tiny, either. In truth, it’s sufficient to capture your imagination and hold you in the illusion. And at the price point, I’m not sure there is better. Imaging is excellent left-to-right, and okay on the depth axis. The stage itself isn’t very deep, so what do you expect? FLC8s resolves at a high level for a mid-tier IEM. It does a fantastic job rendering all the elements in sharp detail. And those elements have better than decent separation. I’m going to say it: these IEMs are stellar examples of what $300+ can get you.

Oriveti’s New Primacy ($299, Review HERE) is another three driver hybrid, with the DD dedicated to bass. It is warmer and less clear than FLC. The bass is flabbier, with a notable mid-bass hump which does cloud the vocals quite a bit. NP’s treble rolls off earlier, making for a less airy stage and less note articulation. FLC8s is to my tastes a proper upgrade to an already excellent IEM in New Primacy. It separates better, renders at a high resolution, and produces a slightly larger soundstage. If you ask me, FLC’s normally higher price-tag is indeed worth it in this case. Between these two, I go with the 8s every time.

Now… the DUNU DK-3001 (currently $469, Review HERE) is an interesting comparison. Here we have a 4-driver hybrid, with a king-hell 13mm DD for bass. It’s a lot like the FLC8s, only smoother, gentler, and altogether more refined. It flows like a clear blue stream and is one of the most pleasant-sounded monitors I’ve ever heard. The bass is everything the 8s is, even tuned the same, only more organic and a goddamn force of nature. The vocals are just as clear and transparent as the 8s, only liquid, and with a less aggressive presentation of details. DUNU’s treble is much smoother and more linear in its rise. And it extends higher, giving even more air to the stage. In fact, the whole slope from bass to treble feels more coherent. Not that the 8s sounded chaotic, but when you switch over to the DK-3001, you hear the difference. Even soundstage is wider and deeper with DUNU. Separation and imaging is about the same, both being super good examples of quality. The only advantage the FLC8s may have over DUNU is in resolution. I feel the 8s is a touch sharper. Oh! There is one other thing FLC does better: Ergonomics. The DUNU DK-3001 has monstrous problems in this area, and FLC is a f**king champion. The difference is so significant it could mean a decisive win for the FLC8s.

My reference player is the Opus#2, and this happens to be a wonderful choice for FLC8s. With its neutral-warm tuning and strong dynamics, it adds an uncolored, bold flavor to these IEMs. Opus renders weighty notes, and a robust, yet refined production. This helps to put some meat on the bones of those thinner FLC mids. Last but not least, Opus’ truly expansive soundstage pushes the 8s to its full potential.

Cayin’s very, very, VERY soon to be released N5II is also neutral-warm, but with a little extra treble energy. It’s a whole hell of a of lot like the Opus#2, but just a small step down in quality, and much less expensive. It pushes the clarity and smoothness of the 8s. The treble seems to take on more air. The bass grows in liquidity, but loses a touch of that visceral impact. Vocals render a crystalline image that is not as natural to my ears. Still, this pairing is awesome and oh so enjoyable.

For the very best in budget range, the Shanling M3s is a delightful choice for the FLC8s. It has a killer low-end, vital, transparent mids, and superb treble presence. It renders at a higher resolution than any of the other budget DAPs I’ve tested, which helps to showcase the 8s’ special talents in that arena. Shanling’s relaxed presentation nudges the 8s a little further down that path, reducing the overall dynamics. It’s a player that performs beyond its price, and brings out the best in some of my more shockingly expensive IEMs. The FLC8s gets everything it needs, and then some.

Alright. There you have it. FLC Technology created a fiendishly good IEM with their FLC8s. Now I understand where all that hype came from. These perform well outside their expected range. The 8s is comfortable, light, easy to use (except some of those filters are a right pain to replace. Be careful!), and did I mention, sounds incredible? The fact is, at this price, I’ve never heard anything better. The FLC8s is an unequivocal recommendation.

-~::Pinky_Powers::~-

____________________________________________________





Background

A current university student on a limited budget here. Subsequently, I don't have nearly as many frame of references as others have (but I do check out the nearby audio store and try out the common open headphones!) I'm not a super enthusiast (yet?) about audio, but music means a lot to me. My files are either lossless/uncompressed from Bandcamp or wherever I can get the source version from. I get some of the basics of high fidelity audio such as sound signatures, presence range, etc. but I'm definitely not a sound engineer. Music is subjective - hence, don't expect a superlative impartiality of sound explanations from me!



From reading countless comparisons and reviews across the wide internet, I ended up with the choice of three in-ear monitors that I believe matches my sound preference: neutral (negotiable, the upcoming aspects are not) with the greatest emphasis on clarity and spaciousness. The three IEMs I had rounded down to after an extensive multi-language search were the Etymotic ER4SR ($349, single balanced armature, known to be the benchmark of IEMs for a good reason), the Audeze iSine 10 ($399, planar magnetic IEM) and the much, much lesser known FLC 8S ($350, 1 dynamic driver + 2 balanced armatures hybrid). Though I haven't tried all three (the perks of living in Oceania... this is not one of them), both the ER4SR and iSine 10 had quirks that became problems for me: the former for deep insertion and fit (I bike as a primary means of transport and the ER4SR would stick out against my goggles; anything but foam tips are not comfortable enough for me to listen for long periods of time) and the latter for having no isolation, supporting Apple devices only while having an off-tone, massive peak between the 1-2 kHz range (the cipher cable they later developed to address this does not match my needs for an IEM). Being a university student studying full-time, I did not have the opportunity or money to splash around to try all these excellent and critically acclaimed in-ear monitors. This was a - very - luxury purchase I have made for myself, and I had absolutely no room for regretting a purchase. Ultimately, after reading many reviews of the FLC 8S, all the goods and bads (one saying that the iSine 10 was so much better (ehh no) than the FLC 8S - in hindsight, that person probably didn't tune their FLC 8S very well) I decided on purchasing the FLC 8S knowing that it would be the least regrettable purchase decision out of the three considering its advertised flexibility of 36 different tuning configurations. And so I brought these on sale for ~US $300 from Lend Me Ur Ears (great customer service, by the way) and eagerly awaited and withheld myself from excitement to try them at the right time and place of mind.





Disclaimer?
I brought the FLC 8S with my own money and felt the need (without anyone's suggestion) to share my experiences with these high fidelity in-ear monitors.









Misleading first impressions


TD;LR
If you experience sibilance and/or hiss with the FLC 8S, throw away the stock silicone tips and use memory foam tips with a good seal in your ear.



So I prepared mentally and physically to listen for the first time. After hearing so many amazing reviews about this IEM, I was completely ready to be blown away. Putting on the smallest silicone tips (so I could get the deepest and clearest fit into my ear), I set down for the revelation of awesomeness.


I was blown away by how horrible the stock tips with Grey/Grey/Gold was and how sibilant they sounded.


Literally, I played a track with NO vocals and I heard hissing (which disappeared when I pause the track; not present in any other IEM I have, so I'm 100% sure it's not equipment) coming from the treble. Changed to another track. Still hissing. A vocal track. The vocals sounded like a ROBOT trying to mimic a snake rattle. They weren't even pronouncing 'S' sounds! Everything was hissing and sibilant so badly, I thought of returning the IEM for repair 10 minutes after I opened the box. They sounded worse than broken. But then I had a revelation of my own. I was going to change to foam tips anyway, but it struck me that the smallest stock silicone tips was the issue (I might miss the "best treble extension" stated by FLC... but with that sound. No. Not at all).

So I changed the tips to Comply TX400 (smallest size, the one with the waxguard filter). It was as if an entirely new experience of the FLC 8S opened up to me. And they did. They stopped sounding sibilant and broken. Literally, all the hissing disappeared from any of my tracks. No exaggeration, it was completely gone. And its not like any other variable could have caused it either, the hissing was so bad that I removed the stock tips after ~2 minutes of rapid-fire listening of many of my tracks. Suddenly, they sounded natural, incredible and normal (the incredible part is helped a lot by the TX400, great pairing to balance the sound of the FLC 8S) like what you would've expect from any non run-overed high-end IEM.

As such, I recommend that you take hold of all the stock silicone tips that came with the FLC 8S,
and throw them away.


(At least don't use them and look for alternatives, ESPECIALLY IF you are hearing unnatural tin robot sounds/sharp edges with them).



Second (unabridged) thoughts on the stock silicone tips

After seeing others praise the stock tips, I decided to give them another try. This time I used the medium size and made sure to get the best seal as I could (doesn't help that these do not adjust to the shape of your ear canal like the complys - felt like it could uncomfortably pop out of my ears at any moment). Tried with the track that I heard unlistenably terrible hissing and sibilance (Krys Talk - Fly Away <Mendum Remix>) and the awful hissing was mostly not there any more. Still, the treble stands out too much and reduces the amazing coherency and timbre of the FLC 8S. Sibilance ("WEU'LL SSHAYSSZEEEE") was still there. On other tracks, the brilliant no nozzle filters configuration started to sound shouty, unnatural and off-tone with the medium stock silicone tips. I did hear marginally more treble detail with the silicone tips, but I'm not sure if you'd really want to hear that with this IEM given that its midrange clarity is absolutely transcendental. I don't think the "most treble extension" silicone tips is a good combination if you want natural clarity from these IEMs. Also they diminish the FLC 8S's awesome detailed subbass and midbass (regardless of your filter configuration) by a lot. This is from someone who doesn't even like bass - it's as if the stock tips absorb the subbass impact or something. Compared to the complys, the stock tips made the sound somewhat tinny and far too bright - it lacks the fullness and wholeness that the comply gives with the IEM. Swapped back to the Comply TX400, and all became right with the world. The coherency, naturalness and clarity of the FLC 8S with the Comply TX400 is just incredible - a match made in audio heaven.


TD;LR stock tips changed from discard/10 to 3/10 listenable with proper fit and improving bass response through red thumbstack. Stock tips has poor bass response, making the IEM sound tinny. Small Comply TX400 (medium and large sizes causes recessed mids and muddies everything up) with good ear seal reveals the capability of the IEM's tremulous subbass while evening out the sound on top of making it feel like its not even on your ear - highly recommended. With it, I can not imagine a better pairing in terms of naturalness and effortless music. If you think that the FLC 8S is too bright or sibilant, then you owe it to yourself to try them with the small Comply TX400 - an incredibly even and harmonious tone awaits you with this pairing.








Quirks


The FLC 8S comes with an earguide hook that you can place on the cables. At first, I struggled for a good 10 minutes to even put the thing on until I realized that the ear hooks actually had "L" and "R" imprinted on them. Trying to put it on the first few times was rather discordant, but now that I know how to properly put them on it only takes me about ~5 seconds (make sure that the ear hooks cover the entire part of the cable; put the ear hook over your ear first, then guide the IEMs into your ear). The ear hooks were very soft and comfortable for me, most of the time I forget that it's (along with the super lightweight IEM) even hanging on my ear (if not for the incredible sound that these produce, that is).

The braided pure copper cable produces a lot of cable noise and should be replaced if you are intending to breathe and/or allow your heart to beat while listening to the FLC 8S. Well, its not actually that bad, but given that the IEM is designed to fit over-ear and yet still produces any microphonics at all (just from moving your head slightly, but the cable noise from this can be unnoticeable by increasing the volume), it definitely is a weakness to consider. I wear my IEMs with the cable over my back so that I never touch the cables and it stays more stable while moving (and also reduced microphonics to zero in my other cable-noisy IEM), but the FLC 8S cable still produced very little-but-still-there microphonics when I did this. For most people, the microphonics will be gone once you increase the volume, but if not, you should strongly consider setting aside the stock cable and seek an alternative, (non-cheap because the FLC 8S deserves great cables!) non-microphonic cable especially if you plan to move around a lot with this IEM. Newer FLC 8S comes with a revised pure copper cable (its more deep teal in color) with a proper non-cheap looking cinch and without the memory wire. I don't notice any stiffness and discomfort with this cable, I was able to sleep listening to the IEMs and the cable got out of the way without ricocheting and hitting me in the face like the other stiff cables I've tried, so I'd say the stock cable, sans microphonics, is actually quite nice.

They are also 1.2m long (for both the 7N pure copper stock cable and the 6N pure silver upgrade cable), which considering that includes the over-ear design may be too short for some. Understandably, these styles of cables are rather expensive (just look at how much Ultimate Ears sells their pure silver cable for... I'll let you guess. Over 60% the price of the FLC 8S... yikes) so I wouldn't consider it a flaw as you can use your own cables either way.

The socket is TF10 and is 0.74mm, so cables apart from FLC's own pure silver upgrade cable could potentially make the earpiece socket larger and slightly loose. They actually advise not changing cables often for the IEM's longevity, so these quirks should definitely be taken into an account if upgrading the cable is to be an attractive option for you.



I'm trying to blow holes at the FLC 8S's possible weaknesses at this point. Aside from the tiny thumbstack and cylinder filters making it potentially difficult to change on the go (I sort of got used to it and can change more often without the filters going and flying everywhere... I think. After getting used to the changing (grip the thumbstacks securely with your fingernails, push down from an angle opposite to the nozzle), it only takes me ~8 seconds assuming that I gripped the parts properly so that it doesn't fly off. Besides, considering how small these IEMs are it's really a given physical limitation) there really isn't much else you could criticise about the FLC 8S. Especially the sound. You can't make a tuneable IEM without being at least very good in all parts of the audio spectrum after all - and for that, they have done super well. I hadn't realised until now that 'You're Not Alone' by CMA actually had cymbals behind the empowering bass. It sits far behind it and is a bit subtle. With sibilance I probably would've just thought that the bass was distorted (its not, the artist's tracks are amazing and well-balanced) because I wouldn't have been able to distinguish between the overpowering bass and the subtle treble. I have no problems doing that with this IEM! The FLC 8S does a superb job of covering the general flaws of IEMs, and I think its very unlikely that its physical aspects would cause issues for anyone. I wouldn't even consider their custom shelled version because the universal one already fits so well for me. But that is an option if one finds the FLC 8S to not fit as well (not likely from what I can tell out of the countless impressions I've read, which is a very, very good thing for a universal IEM).










Impressions Update!




(The review of the FLC 8S continues down below!)













75 Ohm Impedance Adapter










Neutron - Crossfeed | Surround Sound



By now I have tried many things on my quest to bring out the best possible sound from the >magnificent< FLC 8S. I have used the 75 Ohm Impedance Adapter for a while now, and while it does reduce listening fatigue at higher volumes, the added length makes it cumbersome to use when you're out and about. So I have been moving levers around in Neutron's Crossfeed and Surround Sound DSP settings and found that, with the right configuration, these can have the effect of reducing listening fatigue overall while also increasing soundstage depth (for Crossfeed) or soundstage width (for Surround Sound) significantly. The sound improvements are far greater than even the praises I put out for the impedance adapter, I don't think I could accurately describe the experience in words. It's an entirely new dimension of sound (maybe literally with Surround Sound) that I have never experienced in any headphone or IEM - ever, and the FLC 8S's superb technicalities and tuning ability have allowed me to hear and discover this new galaxy of sound better than any other sound producing equipment I have tried.


Descriptions of the perception of where the sound comes from may vary based on your setup, the ear tips that you use, ear tip insert depth, and your configuration. Oh, and your own ears, too.



These are the greatest and most significant improvements in sound I have heard thus far.





Crossfeed




Music flows serenely in the background, allowing you to be focused and immersed in other tasks. Improves soundstage depth with the side-effect of lowering the volume and pushing the music back noticeably, making music very easy to listen to.








Surround Sound




Vocals span the space around your head, creating a large area of perception for audio. The sound is not perceived close to you or has the left speaker/right speaker obvious sound location pinpointing, which also makes it comfortable to listen to like crossfeed. Surround sound demands more of your attention naturally due to the expanded soundstage width.












The differences that crossfeed and surround sound makes are just too significant to put into words. If you are interested in improving soundstage depth (crossfeed, surround sound to a lesser extent) or soundstage width (surround sound), try them out. It just has to be heard to comprehend the massive differences that they make to the sound.











The Pure Silver (Single Crystal) Upgrade Cable



Let me preface by saying that the stock 7N pure copper cable (minus the microphonics) is already very good. Either the stock or the pure silver upgrade cable will offer great sound without issues (0.74 mm pins). The 99.9999% (this is expensive stuff) pure silver upgrade cable comes with memory wire which I can adjust to stop the cables from touching the back of my neck (compared to the ear hooks, which points the cable inwards slightly due to its shape). It also allows a more secure fit on your ear in case you're doing gymnastics or something with these IEMs. The cable is the same length, still with microphonics (though somewhat reduced maybe? but with more shape retention), so don't expect much of a difference in those areas. The upgrade cable does have 400D Kevlar at the core though, so it'd probably stop a bullet before failing out (the price would be mainly due to the single crystal silver they used - its not cheap). Any improvements in sound quality made beyond upgrading the actual IEM itself is not as large (unless your source files are really bad), hence divisive and subjective (we sure know that on this forum!), and depending on your setup and circumstances, the differences might be massive, it might be slight, or there might not be any perceivable difference at all. With that said, I'll try to describe the differences (and improvements) I hear when swapping from the stock pure copper cable to the pure silver upgrade cable deliberately and exactly. First, lets get some things out of the way first.


The difference between copper and silver is that silver transmit electrical signals ~5% better than copper. You can look it up and see why people even bother with expensive silver in high end equipment!


But would you really notice that 5% (real-world estimated, not likely to transfer exactly to listening experience) difference? Theoretically, it might improve sound performance (again, theoretically). But how would you be able to measure that? A cable shouldn't be changing the sound frequency (unless its very bad or is intentionally designed to do so) and an artificial model can only do so much to imitate the millions of different variables creating different overall experiences to the sound that makes audio fidelity perception inherently subjective. I can't speak for everyone, but since the audio-focused FLC released these cables (at a small sum of $100 dollars), I felt that these might actually make some differences (though I am not inclined to think so), or that they should if they bothered to make it given they said that they worked so hard on perfecting the 7N copper stock cable. So, now I got the pure silver upgrade cable (the FLC 8S really impressed me!), this is what I have noticed after listening with the stock pure copper cable then swapping immediately to the pure silver upgrade cable with my setup:















- In Phillip G. Anderson's 'Winter', the subbass of the orchestral drums are tighter and more refined. The bass not only has more impact like you would expect from boosting subbass and midbass - the impact is clearer, as in the specific repercussions could be felt (I also felt this with the stock cable but the pure silver upgrade cable does this rumble effect more cleanly and distinctively). The echoes of the drums seem to extend slightly longer, making everything sound more natural.


- In the soundtrack 'What Becomes Of Us' from Final Fantasy Type-0, the female and male choirs sounded somewhat fuller (not in terms of soundstage depth or anything, but rather the opposite of 'thin' sound), I could hear the background layers of vocals a bit better.


- Hammock's 'Ten Thousand Years Won't Save Your Life' sounds fuller and overall more whole. The violins are more intimate and impactful.


- The piano in DJ Okawari's 'Flower Dance' and 'Luv Letter' sounds like they have more presence (not thin or forwarded - the instruments sound more balanced and is comfortably in their respective places), sounding more natural and slightly more real compared to the stock cable.


- The wall of treble in Porter Robinson's 'Sea Of Voices' sounds somewhat more powerful with a higher sense of density.



The improvements isn't just better resolved bass, though that would be the first thing most would notice when not listening analytically. In all of my tracks (even in ones that doesn't boost the bass very much), the bass rumble sounds and feels more detailed - there is more of it when the music presents bass (though still completely silent when it doesn't). Secondary layers of vocals sound more pronounced compared to the stock cable, though I do not notice an increase in treble quantity (which is a good thing as the FLC 8S already has a lot of treble). This makes the FLC 8S feel more powerful, not in a typical bass boosted sort of way, but in terms of offering a more realistic presentation of music. I can definitely see and hear why they call it an 'upgrade cable' for the FLC 8S.






A year after - Impressions update
My initial impressions were too modest. The silver upgrade cable is AMAZING with the sound it enables for the FLC 8S! The newer cables don't seem to have any audible microphonics at all, the cinch is now the same as the stock copper cable (i.e. no longer a cheap looking plastic tube, instead something sturdy and easy to use). No more memory wire that's shown in the impedance adapter picture above, but I've never found the lack of to be an issue (even while cycling) if I wear the cables over my back with the cinch up to the back of my head. And the sound. Everything is somehow even more clear, including the subbass (20 - 40 Hz) and lowbass (40 - 80 Hz) precision and naturalness that I've mentioned previously. I can hear the vocalists' breaths at the beginning of every sentence more easily compared to the stock copper cable, yet it still does not sound fatiguing. The entire frequency spectrum is just rendered better. That ~5% difference in conductivity between copper and silver is absolutely being utilized here (not to mention the expensive 6N 99.9999% silver purity), and if you're familiar with how the FLC 8S braided single crystal copper and silver cable sounds, I would go as far as to say that the differences will present itself to you.


For example, I have several music files that primarily uses the 19 kHz region at certain parts of the track (which the spectrogram shows it being as loud as the bass region; it manifests as faint light note scribbling/wind sound), on the stock copper cable it was audible and kind of there, but with the pure silver cable it was - easily - noticeable and effortlessly presented. Upper frequencies 16k to 20 kHz reminds me somewhat of the Shure KSE1500 (that I've demoed twice, pretty much unparalleled detail in mids and treble but Balanced Armature-ish bass with little to no decay compared to the stunning natural subbass of the FLC 8S's dynamic driver) with the silver upgrade cable, it's just super glorious. Treble sounds more accurate, but not harsh, and the subbass - I can feel the gentle but powerful and clean rumble of the subbass and lowbass in my chest and even down to my stomach if I turn the volume up high in certain tracks (like Nero's 'Promises') with the red thumbstack! Listen to the beginning of Max Richter's 'November' and you can FEEL the precise and clean rumbles with the red thumbstack filter (but it doesn't affect the clarity of the mids at all! Hybrid IEMs huzzah!) I've just mentioned how incredible the FLC 8S's subbass is with the silver upgrade cable, red thumbstack and easy-to-get-a-complete-seal small comply TX400, right? Listening to the combination as I'm writing this, I felt the need to say it again. I've heard top-of-the-line headphones like the Stax SR-009S and the Sennheiser HD820 and they do not compete with the FLC 8S IEM in subbass quality and naturalness at all. If you're looking for an upgrade to the FLC 8S, buy the silver upgrade cable (or if you're uber rich, import the ~2k USD clockwork gear tuning 135 sound combinations FLC Celeste from Hong Kong). I'll resolutely assert that there is no better universal and tunable high fidelity sound than this at the now ~300 USD price range after trying the stock copper for a while then switching back to the silver upgrade cable!






But, of course, this is my subjective perceptions of the improvements I've noticed. While I can definitely pinpoint the more defined subbass and lowbass (Phillip G. Anderson's 'Winter' is a very good example of this, as well as Torsti Spoof's 'Faith'), someone else with different audio equipment, music tastes and several thousand other things may notice something else entirely or nothing different at all. It's all subjective approximation either way. Some people might not be able to distinguish a pair of Beats over the Sennheiser HE 1 in a blind test, and that's okay too. What experience that person perceives and prefers is what matters. For me, the pure silver upgrade cable offers a nice improvement to the sound of the FLC 8S, and with that I'd say it's worth using over more convenient custom cables. After all, I brought the FLC 8S for its incredible sound; if you listen to music through IEMs a lot like me and you enjoy the FLC 8S's tuning capabilities and sound, it might be worth getting if price is not a factor - the pure silver upgrade cable presents a sound that is slightly more real and more complete in all types of music.









Subjectivity to consider


Sound quality is influenced by an astronomical number of factors - the genre of music you like the most (which generally determines the sound signature/IEM you would prefer), the shape of your ear canal, the sources of your music (smartphone versus dedicated amplifier, file quality), the list goes on. All these things could have the potential to affect sound quality drastically (again, dependent on your circumstances) as I've demonstrated with the smallest stock silicone tips and small Comply TX400 in my first impressions of the IEM, so your experiences can and probably will vary to mine. I am from a perspective that clarity and spaciousness above all else matters for high-end headphones, and with that said I am rather aversive to bass and its tendency to make tracks feel like a nightclub party (have used a bass reducer equalizer ever since I've started to listen music more attentively, which I now longer do with the FLC 8S because it is no longer needed - the clarity and balance is incredible). Of course, treble standing out is not a good thing (usually destroys the timbre and harmony of the music) so its a very delicate balance for me in the sound that I prefer. The FLC 8S allows me to achieve this balance and change the sound based on what I feel like listening to (upbeat EDM for biking, Ambient for relaxing/studying) which to me makes it understatedly unique compared to every other IEM on the market. Of course there will be more technically proficient IEMs out there (the electrostatic Shure KSE1500 for example), but the FLC 8S's versatility and comfort to my ear makes it the best use-everyday high fidelity IEM I could imagine. Because everyone will invariably have different experiences and perceptions to audio, I would like to speak from my standpoint, particularly the configuration which have led me to praise the FLC 8S so much. You should get a chance to hear these configurations first before modifying your expectations (for better or worse) of this IEM.



Small size Comply TX400 memory foam with waxguard
Comfortable and removed all sense of sibilance I heard from my first impression of the FLC 8S. For those who believe that the FLC 8S is on the bright side for an IEM, these will very likely change that perception in offering a more balanced and customizable sound.



What have blown me away:



Grey | Grey | No Filter


Immensely coherent and harmonious sound with stunning resolution, forwardness and clarity of the midrange.





Red | Clear | No Filter


Detailed energetic bass response with great clarity. Midbass recessed, but potentially offers a wider space of sound.







________________________________________________







The Sound|s| of the FLC 8S


Filters - Thumbstack [Subbass] | Cylinder [Midbass] | Nozzle [Midrange and Treble]


Colors, most to least respectively:

Thumbstacks
Red
Black
Clear

Cylinders
Black
Grey
Clear

Nozzles
Green - Most treble
Black - Medium mids, second most treble
Gold - Most mids
Blue - Deletes treble and reduces midrange

(I will be calling the black thumbstack filter grey for coherency and color-coordination).


There is actually a lot more to know and discover about the FLC 8S beyond the claimed 36 configurations design. Changing one filter affects the rest of the frequency response and thus the sound. For example, using a clear clear black configuration will push the frequency peak of the black nozzle filters slightly from ~1.3 kHz to somewhere closer to 2 kHz (check out the graph measurements at innerfidelity for a comparison) compared to any other bass filters combination. This means that changing just one filter can have a larger than expected effect on the entire audio spectrum, particularly the midbass cylinder filters which determines how much airflow goes into the IEM. Basically, the FLC 8S can be VERY complex and advanced if you choose to go the advanced tinkering route (someone in this forum added an acoustic dampening cloth to their cylinder filter - the frequency response changes were rather interesting!). On a particular track that I found had too much treble coming from one side, I literally removed the cylinder filter with my hands from that side, WHILE listening to the IEM, and found that side suddenly becoming more coherent! It should be noted that the general issue of disjointed sound found in other hybrid IEMs is nonexistent with the FLC 8S. The combinations of drivers are exceedingly technically well-tuned that they overlap and blend in sound, creating a natural sounding hybrid IEM that doesn't sound off-balanced, being just as whole and pleasing as single-driver type style IEMs (maybe even moreso with the brilliantly clear, wide midrange of no nozzle filters i.e. what the IEM is wholly capable of in terms of 'soundfullness'). Now, I'm not advocating for mismatching the volume and frequency response of the IEM, but it shows the deep potential and customizability of the FLC 8S. I don't think I would be exaggerating in saying that these are perhaps the most customizable IEMs ever released (at least for the time being... new technology are so limited and expensive!)



Since I don't have frequency response graphs to show (the other reviews have already done an excellent job on this), I'll just (not word for word) quote FLC's founder Forrest Wei on precisely what the filters do.



"Without the ULF plug [Thumbstack], the earphone will be like an earbud; you could wear it to run.
Without the LF plug [Cylinder], the midbass is about 2 dB higher.
Without the nozzle, the mids will be higher around 2K Hz - vocal is more forward, the treble will lessen at around 4~5K Hz, sibilance will be less, but the treble would not be so solid and bright."



You could probably get it from his explanation on what the functions of the filters are. The purpose of the filters is to control how much specific sound frequencies are dissipated from the IEM before reaching the nozzle and into your ear. What this means is that there are actually even more (!!!) ways to tune the sound than the stated 36 configurations if you get creative with the no filter combinations.



No Thumbstack filter
This covers the area where the dynamic driver rests. It removes (maybe all) low-end subbass from the IEM and make it sound as if they sit outside your ear, even with a perfect seal. From what I've noticed, this makes energetic EDM tracks or anything reliant on bass sound bad as if the entire low-end frequencies are missing. This may be a good thing on some poorly mastered tracks or orchestral music, but for cohesiveness of sound, using at least the clear thumbstack filter for reduced bass (instead of removing bass entirely) would be recommended for most styles of music.



No Cylinder filter
This covers the area where the dynamic driver and two balanced armature drivers are situated. According to Forrest Wei, this option is the most bassy option of all, offering 2 dB more bass than the max bass filter (black cylinder). This is accurate in my experience, as the moment I remove this filter while listening I was greeted with bass energy that wasn't there before. Using no filters here provides more airflow for the dynamic driver, and in increasing midbass controls the presence of the higher end frequencies. Having no filter here at all noticeably reduced the clarity of orchestral tracks, particularly the piano where it became harder to discern the particular notes as you increase the midbass. To reiterate: removing the cylinder filter and using none will actually increase bass presence and energy. The clear filter here gives the dynamic driver the least amount of air (aside from taping over the port completely) for the bass, so you can tune subbass and midbass separately which makes the various interactions with the filters rather interesting - you could come up with some unexpected results by changing this filter in combination with the others!



No Nozzle filter
This is the final filter before the sound reaches your ear, and arguably its removal makes the FLC 8S shine. Using no nozzle filters as FLC founder Forrest Wei says will make vocals sound forward while simultaneously reducing the treble around 5 kHz (which according to the presence range definition you can find in the forums, would make instruments 'more distant and transparent'. I interpreted this as greater clarity and spaciousness on the FLC 8S). With no nozzle filters, the IEM becomes somewhat mid-centric, which would sound unusual if not for the FLC 8S's excellent technical capability. With no nozzle filters in place I was able to pick out minute details that was not present or less noticeable with the black, blue or even gold filters (the green filter was only partially equal with music that extensively utilise/mainly focused on the high ranges above 6 kHz). The sound could actually be characterised as an enhanced gold filter experience. Detail resolution expanded when I took off the gold filters and put the Comply TX400 on in its place. While the default configuration of Grey/Grey/Gold filters was great and supremely harmonious, using no nozzle filters made me felt moved - by the sound, and I found myself involuntarily moving to the rhythm with a smile on my face. No nozzle filters definitely deserves to be heard (can't say the same for no thumbstack filters). It makes the midrange sibilance-free and clear with impressive imaging and a great sense of expansiveness.



I can't say much about the thumbstack and cylinder bass filters as the preferable tuning of these are highly dependent on the music you listen to. Increasing any parts of the bass should eliminate any sibilance (with Comply foam tips plus waxguard) that you might hear on even the most awkwardly mastered tracks. I will say that the subbass of the FLC 8S (with red thumbstack filters) goes very deep. Compared to a V-shaped IEM with more midbass, in the track 'Winter' by Phillip Anderson, the drum parts were seismic (if you have a complete seal with foam tips) and I could feel the specific repercussions of the drum's echoes. With the more midbass V-shaped IEM using the same foam tips, I was not able to feel the same effect, it didn't really came close to reproducing the detailed and powerful subbass of the FLC 8S. With red thumbstack, its pretty strong in the subbass department for sure. Midbass is quality in terms of being detailed, though there isn't as much quantity as there is compared to the subbass (I might not be holistic with this, my last IEM essentially attacks you with midbass) so you might not feel the midbass of the FLC 8S as much as you would feel its subbass. As others have said, low mids are not affected by the tuning components as far as I could hear (i.e. it didn't increase with the configurations I've tried, I guess its an intentional tuning to make the IEM sound more detailed and spacious?) so instruments like violins might be detailed, but not feel as full compared to a midbass elevated IEM (this was with my equipment, I have heard that this aspect improves with dedicated amplifiers so try that out if you have it!). Though I regard the sounds of the no nozzle filters configuration to be the signature highlight of the FLC 8S, the nozzle filters give flavors of sound that could better suit and enhance the music you listen to. Your primary choice of nozzle filter would thus likely be dependent on the frequency ranges that your music tend to produce and emphasise.





Blue Nozzle
Matches | Dark, enclosed, bass-heavy


Listening casually, focusing on other things.


I tested these out with the stock medium silicone tips (offers the most treble extension according to FLC).

| Destroys treble response and reduces the midrange considerably, but offers more bass rumble and presence. Good for having music sit in the background. |


Coming directly from no nozzle filter with the TX400 tips, the blue nozzle sounded immensely muffled in comparison. It sounded so bad initially that I relegated the blue nozzle from the blue container to one of the plastic accessory bags (where I'll likely not touch it ever again). The blue nozzle mimicked the sound of my 5+ years old Apple EarPods quite well (enclosed, filtered, though with incomparably better detail retrieval obviously) so there's that going for it. That sounds way too harsh, because it is (don't actually compare the Apple earbuds to the FLC 8S - the differences exist in parallel dimensions separated by infinity) - its intended to show the MASSIVE difference between the audio clarity of no nozzle filter and the blue nozzle. And I would assume that you're looking at the FLC 8S for its stunning brillance and tendency to make you react passionately to the music. It probably wouldn't be found with the blue nozzle.


With that said, after listening to various tracks for an extended period of time and getting mentally used to the sound, I did notice that they offer more bass and thump. If you manage to get used to the sound of the blue nozzle, then it will still sound good regardless as the technical prowess and tuning of the FLC 8S is phenomenal. The blue nozzle could be regarded as offering a more lounging friendly sound - if you don't focus and listen attentively, they might be good for relaxed listening or just having music sitting in the background while you do something else (might not work if you have a good seal increasing the sense of bass/going for isolation in loud environments). Though after listening with no nozzle filters, I can't imagine why anyone would want to use the blue nozzles, they don't exactly play to the FLC 8S's strengths. Regardless, its a nice option to have if you want to just relax without feeling moved by the sound of the FLC 8S at the best parts of a song.


For listening closely and for intending to use these as the primary filter though - if your music selection consists of something along the line of 60% bass, 30% mids and 10% treble (in every song you listen to), then the blue nozzle might sound good in enhancing the bass feel at the expense of everything else. Whether that would be worth it to you, well, you'll just have to try it and find out.


Who knows, you might enjoy feeling the music more than you do listening to it. If that's the case, the blue nozzle might be of use to you.





Green Nozzle
Matches | Airy, not vocal-oriented, clarity necessitated


Listening to the nimbility and gracefulness of orchestra.


| Quick and precise treble imaging. High amounts of detail at the high ends, amazing for piano. May produce very noticeable sibilance in vocal tracks depending on the bass filter combination used. |


With my previous bass-heavy V-shaped IEM (Degauss Labs Noir), orchestral tracks or anything that emphasises the piano sounded... not good. The boomy midbass contoured and muffled everything, reducing the ability to distinguish the notes of the piano, so everything sounded very muddy and 'samey' as far as orchestral tracks go. Experiencing the green nozzles of the FLC 8S have opened a new door for me in music. A good benchmark for audio clarity of piano would be the track 'Blink' by James Maloney. The piano here is VERY quick and absolutely demands precision and clarity in the higher ranges or else the presentation would be very bad. With a V-shaped sound signature, the piano sounded like a mushed blur. Absolutely no detail could be distinguished because it was so blurry. With the FLC 8S's Clear/Clear/Green combination, I could distinguish every piano note and realized that the piano was actually linearly moving up and down in notes rapidly - and I could hear all of those notes without extensive focus. That is the clarity that these nozzles offer. When I changed the clear cylinder midbass filter to the grey one, it became more difficult to discern the individual notes. So if I were to use the green nozzle, I would definitely only stick to the clear cylinder filter to make sure that the treble isn't reduced from the more open port. Any subbass filter should be fine here for the most part - I didn't notice those directly affecting the clarity of the piano as much as the midbass filters.


A downside of these filters however is the added sibilance and unnaturalness added to vocal tracks. Vocals started to sound like they came out of a cymbals sound mixer instead of an actual human being. 'Chase' in the track Fly Away by Krys Talk/Mendum (the track where I noticed the horrendous sibilance in my inital impression) becomes 'shayse' with the green nozzle. And this was with the small Comply TX400 with waxguard, which is known to reduce and harmonise the treble. I can't imagine how bad the sibilance would be with any other tips (actually, I can - refer to my initial impressions with the unnatural silicone treble blaster-err I mean stock silicone tips).


I also noticed that everything had less sound decay in general, because the treble would just move from one note to another quickly without really letting it fade away naturally (like the sounds coming from the dynamic driver, which sounded more natural). As such, this nozzle is definitely not 'main-use'-able unless your music selection consists mostly of vocaless tracks. Would the green nozzle be worth keeping around for changing? Again, that is up to you and whether you like treble or not. The green nozzle filters does not destroy the spaciousness of the music like the blue filter does (actually it could be seen as enhancing it slightly), but it does destroy any sense of naturalness if your music is particularly vocal heavy. All in all, the green nozzle filter is a nice option for those looking to enhance their piano listening experience. It has the potential to make orchestral imaging astonishingly wonderful.





Gold Nozzle
Matches | Smooth, intimate, sibilant recordings


The fullness of vocals.


Referred by many as 'liquid vocals', the gold nozzle pushes the emphasis towards the ~2 kHz range while reducing treble noticeably around 8 kHz (resulting in it eliminating sibilance really well). It helps with the finish of the vocals, making them sound more 'complete' in a sense. The tradeoff is that there can be a lesser sense of space because the vocal is closer to you (though imaging and soundstage is excellent like the other non-blue nozzles), but it's definitely not as enclosed as the blue nozzle.


This nozzle can help with tonality and naturalness for some because it smoothens out the sound while bringing vocals to the center stage. It offers a slightly more natural decay of sound compared to the black nozzle for example at the expense of treble details. Treble is definitely pushed back with the gold nozzle, so that is something to take into consideration. You won't feel like being surrounded by clouds with this nozzle, but rather you'd feel like you're comfortably on the ground, at the front seat of a live performance. The gold nozzle sets out what it aims to do really well, and should work well with all styles of vocal music.

In sacrificing some airyness (treble) for a smooth tonality, I can definitely see a lot of people enjoying this nozzle filter.





Black Nozzle
Matches | Neutral, most music, forwarded instruments


No particular emphasis on anything. Easeful reference balancing.


This nozzle is quite neat (literally). According to innerfidelity measurements, they roughly emphasise the ~1.3 kHz and ~9 kHz ranges, so they could help with providing a fuller sound at higher ranges (for reference, the green nozzle filters also emphasise these ranges). Actually, comparing the black nozzle and green nozzle frequency response graphs, you could say that the black nozzle filter is the more balanced version of the green nozzle. It is the filter with the second most amount of treble (roughly ~4 dB higher than gold nozzle it looks like) and as such you might notice slight sibilance on a few tracks (increasing midbass helps alleviate this). It can work very well for those looking for a more linear extension and sound. I can't really say much else about this nozzle however, because nothing really stands out in my tracks to me using this. Is that a good or a bad thing? You decide.





Grey | Grey | None
Matches | Everything



Clarity and reference sound comes to life.




This, to me is the absolute highlight of the FLC 8S's coherent tuning and preeminent midrange. To reiterate on what no nozzle does: "without the nozzle, the mids will be higher around 2K Hz - vocal is more forward, the treble will lessen at around 4~5K Hz". From my listening, some definitions and playing around with a music editing tool and increasing/decreasing those specific ranges, I've found that this gives the most spacious, yet complete sound of all the nozzles. Listening to 'Times Like These' by The Eden Project, the vocals are paramount, spacious and effortlessly clear while the entire track emanated energy that made me feel the need to move along with it. I hadn't realised that the chorus had more than one vocal sound (there's another layer of vocals, who could've guessed with that clear singing!) before listening to it with the FLC 8S. Likewise, the awesome 'Wake Up' sung by the same person sounds incredibly passionate with this configuration - I could hear them breathing in lows and highs (I could differentiate how they breathed for each word they spoke with the no nozzle filter) without any sense of sibilance. It really, really is amazing how clear these are. With experiences like these on a constant basis across all of my music, I knew immediately from early listening that these were absolutely worth the price point (and I would say even more! The pure silver upgrade cable is an option...) - these sound coherent on every genre that I listen to, from classical/orchestral or ambient (which tends to sound blurry and congested when there is too much bass and little midrange - the FLC 8S is revelatory for me here!) to EDM (tune the FLC 8S to lift the bass and hear the pumping adrenaline beat!). These genres of music could not be further apart in terms of sound signature and emphasis - EDM needing midbass and midrange while Ambient needing midrange, treble and reduced bass. With the right sound tuning of the FLC 8S, such as this one (you might find others depending on your equipment!), both sounds amazing without the need for an equalizer or anything similar (unlike the other IEMs I've listened to. Equalizer can't make those excessively exaggerated peaks found in non-neutral, boosted IEMs sound good, believe me I've tried). Using lossless files, this IEM is incredible in evoking the more subtle details of well-mastered tracks. What is yet amazing is that you can still improve the already awe-inspiring sound with some advanced tinkering and better amplifier combos (+ impedance adapter) as well as using an equalizer (though absolutely not needed!). The FLC 8S sounds amazing at low volumes, and even better with a good impedance adapter and source at higher volumes! Still hearing some treble standing out? Remove the cylinder midbass filter from the right ear piece of the FLC 8S and feel the music even more!







"Clarity" and "legendary variety of sound"



I previously used the Degauss Labs Noir, a V-shaped hybrid (1 dynamic driver & 1 balanced armature) IEM with a midbass boost. I'll compare the Noir with the FLC 8S back and forth to describe what I mean by clarity and effortlessness, at least from the perspective of a non-super enthusiast. The Noir is by all means a good IEM, excellent for its goal of sounding energetic and impactful, but I do not even doubt for a second in saying that the FLC 8S offers (much) (but-I-wouldn't-say-that-the-Noirs-are-bad) greater clarity and detail retrieval - it's immensely obvious because the less pronounced details stand out and make an impression on you. For example, with the track Quasar by Michael FK you can hear subtle, multiple layers of airy voices throughout the entire track, effortlessly presented with the FLC 8S at medium volume while I have to increase the volume to loud to even hear the layered voices on the Noir. While this is partially due to the characteristic of the Noir in having a V-shaped sound signature with bass boost (the combination generally reduces the ability to pick up subtle details due to a recessed midrange), reducing the bass with an equaliser did not make hearing the details easier. You have to squint and listen closely to hear the details, and even at ear-destroying volumes the Noir does not resolve all the details that FLC 8S does so effortlessly. Swapping back and forth between the IEMs there are so many echoes and sounds that I have never heard before when quickly changing to the FLC 8S, such as the echoes of the speech found in Moonlight by Rameses B. Effortlessness also improves other aspects such as airyness - the airy treble in Porter Robinson's Sea Of Voices is so awesome, easy to listen to and clear! By 'detail' I mean the character of the sound, so for example while the Noir produces much more bass, the bass is just "bass" and sounds like what you'd typically expect. The FLC 8S is able to produce the same amount of bass at a greater level of detail, allowing you to discover new things each time you listen, which makes re-listening to your music fun and exciting. The nuances of tracks presents itself to me clearly and distinctively and does not need me to critically listen so that I may hear them.



Want to be mind-blown even further? Listen to

Red | Clear | None

and feel the clarity of sound!



It sounds absurd, but I actually feel moved listening to the FLC 8S even without the energetic tuning due to the sheer clarity and detail presented that I have never noticed before. Put simply, the music feels more 'alive' despite not presenting that exciting V-shaped sound that is highly popular among IEMs currently. It's an incredible hallmark of high fidelity audio that makes pursuing music truly rewarding, and the FLC 8S offers this astronomical leap more seen in $1000+ headphones at a $350 price point. It's astonishing what FLC have accomplished as a new company with the 8S - they didn't just make an amazing in-ear monitor that surpasses the typical downfalls and flaws, they made one that could potentially sound like 5 distinct IEMs (and potentially much more if you're crafty) for the price of one, with its own breathtakingly beautiful midrange character. The FLC 8S doesn't just stand out, it shines with the face of a thousand suns, and should be the premier headphone recommendation for those looking to take a flexible and unregrettable step into higher fidelity sound. For some, it could be their last pick for the foreseeable future of driver-based headphones, and in which case I can definitely see why. The FLC 8S is the most versatile headphone out there right now, and its clarity, resolution and uniqueness could be appreciated for decades to come.