FLC 8s

FLC 8s

I was loaned the FLC8s to audition before purchasing the b400 or LZ A4. I did not cover un-boxing or the accessory kit as I received the product without the box and with filters already mounted. I’d like to thank @Ngoshawk for graciously loaning me the FLC8s to try. I’ll admit, I really don’t want to return them but will have to buy my own soon.Build
The 8s by FLC is a smaller than average uniquely shaped iem designed for over ear wear. The housing is all plastic which may turn some people off, but seems well enough put together. At first glance, I thought they might be colored aluminum shells due to the fit and finish. The housing feel solid and seams fit well with no obvious gaps or mis-alignments. I saw no weak points in the shell that I would worry about coming apart over time. The fact that 3 different filters fit into these small housings means that any slight misalignment or wobble during production and everything fails to work correctly. Filters themselves are tiny and with these being on loan, I was very weary of potentially losing one. Once attached, they stay solidly in place so no worries during use of the 8s but when changing filters, it can be a challenge for aging eyes and clumsy fingers.


The best news for me was that the 8s arrived with the upgrade cable already in place so I avoided use of the stock cable except to do some sound comparisons as Ngoshawk requested my thoughts on the cables. The stock cable is overly stiff and combined with my glasses was an uncomfortable fit. Were I to purchase the 8s, I would have to buy the upgrade cable as the option to go without glasses or without music is simply not appealing as both seem rather necessary. The upgrade cable still has a bit of memory and isn’t the most pliable cable but does make a vast improvement in comfort for me. Although I am reluctant to attribute any auditory changes to a cable, the silver single crystal cable did seem to make a bit of improvement particularly in the low end. The cables use the 2 pin UE connector type making it a little more difficult to find replacement cables and those who prefer a more supple cable will certainly have to do some looking at aftermarket options.

Stock Cable

Upgrade Cable

Fit and Isolation
The shape of the 8s combined with its lightweight and smooth surfaces made it very comfortable to wear although the nozzles do not have a forward angle as some other earphones do and may cause some problems with fit for those with small ear canals. For me, they fit well and when paired with symbios tips the seal was good although a bit shallow. With the ports in the earphone itself and the shallow fit, I can only describe the isolation as mediocre. If I had to guess, I’d say somewhere around a -12dB reduction of outside noise.


This is the hardest part of this review by far. The fact is: the 8s sounds like whatever you want it to. The filters really do work, you can tune the 8s to be a bass cannon if that is your thing, or head the other direction and create an absolute treble knife. Most will probably tune the 8s somewhere between those extremes and with 36 possible combinations a lot of middle ground exists. I’ve tried to make notes about the driver characteristics that come through regardless of how you adjust as well as notes on specific filters where they have a noteworthy impact.

In order to understand the sound options, you have to understand the filters. The inner port on the shell tunes the sub-bass frequencies, the outer port tunes the bass frequencies, and the screw in nozzles control the mid and high frequency response. The filters come packaged in an aluminum tube with a key ring adapter. This is misleading as changing filters on the go is certainly not recommended as the parts are tiny and the operations are tedious. I recommend changing filters only on a large flat surface (preferably light colored where the filters don’t blend in) with good lighting and perhaps a razor blade and set of angled needle nose pliers as the provided tweezers are less than helpful. Using a scalpel blade to get under the edge of the filters and lift is much easier than trying to get enough surface area exposed to use the tweezers. The housing ports are all pressure fit, so pushing the filters in requires precise orientation and gentle pressure. The nozzle filters are larger, screw-in and much easier to work with.
outerfilter.JPG inner filter.JPG Nozzlefilter.JPG

The following were things that I noted regarding the 8s regardless of which set of filters were installed. First and foremost, for a hybrid BA/dynamic, the 8s has better coherency than most. Unlike some hybrids, I would be hard pressed to tell you which frequencies were being produced by which driver in the 8s. Extension is great at the top end and good at the bottom. These have no large roll-off at either end of the spectrum. It didn’t appear to me that the lower mids were changed at all by the tuning filters. The upper mids and high frequencies were quite obviously shaped by the nozzle filters but if the lower mids were moved at all it so slight as to be imperceptible to me. Lastly, the level of detail and micro-details were better than expected and would have made me guess this was a more expensive headphone had I not known the price going in. Overall, I would say the 8s retains a slightly bright signature regardless of which filter set you choose.

The low-end is shaped by both the sub-bass filter and the bass filter and I found that I enjoyed the red sub-bass filters but needed to back off the bass filter by one level as the bass got a bit boomy and lost a bit of control when wide open. Stepping back a notch to the black filter did lose a bit of quantity, but gained a lot of quality so it was a trade well made. Overall, the sub-bass extension was better than I thought possible out of a 6.4mm driver and the bass was well rendered unless the wide open (filter less) setting was used. I would have liked to see a bit more bass quantity but not at the expense of quality. If you are a bass-head, this is probably not the earphone for you as it trades quality for quantity when you try and increase the bass in a way that is not pleasing.

as noted the lower mids are not shaped by any of the filters so you have less options here. The good news is I didn’t hear a pronounced mid-bass hump and any bleed into the lower mids was very minimal. Instrument separation is good and male vocals are lifelike and ever so slightly forward. The upper mids are much more tunable with the filters and my favorite was a slightly bright filter that lifted female vocals a bit and brought a bit of extra air to the top end. I spent quite a bit of time trying the green and black bores, which are either medium mid and most high frequency or medium mid and high respectively. I came to the conclusion that depending on the track, I could continually swap these two filters and never resolve a single filter that I liked best so I settled on the black as a compromise.

having just said I settled for the medium high frequency filter, I really enjoyed the sparkle and air the green filter brought to the table and with all but the most sibilant of tracks the green filter really did bring more life to the sound signature. For some reason though, I found the green filter a big more fatiguing than the black which dialed it back a notch. I tried to go without a filter as some recommended but found that was extremely fatiguing unless I dialed back the 6kHz and 8kHz by about 6dB.

Truth be told, none of the mid/high filters were exactly the combination I would have liked and a little EQ combined with the green was my best fit. If using a player that didn’t have EQ, the black was the best compromise.


I found the 8s to have a very wide soundstage if not quite as deep as it was wide. Imaging was good with instrument placement easily visualized and movement of singers on stage in live performance well rendered. The 8s is easily one of the best in-ears I have had a chance to audition when considering imaging and I suspect this is one category where the 8s punches well above its weight as I have had the opportunity to audition several other IEMs in this price range and none come close.

The FLC8s is one of the best IEMs I have had the pleasure to audition in quite a while. Admittedly, I usually shy from auditioning things too far out of my price range, so I cannot make the direct comparisons to flagship IEMs that I am sure others will. I can say that without any tuning tricks, the 8s is one of the best IEMs I have heard for coherency and performs with a natural ease to its sound that I haven’t seen in this price range before. With the filters, the tuning options open doors to all kinds of signatures. While I would love to see them decouple the mid and high filters to give even more tuning options, I have to say I was not displeased at all with Red, black, Green or red, black, black. Both of those cater to my tastes with good sub-bass, controlled bass, no bleed over into the mids and nice forward upper mids and treble. This takes an already good voice and tailors it nicely to my personal tastes. Give the FLC 8s a try and I’m sure you can find at least one combination of filters that suits your style too. As for me, now I have to find my own pair so I can return these to their owner who is already regretting being without them for 2 weeks while I had them. Thanks again to @Ngoshawk for introducing me to such a great IEM.