FLC Technology - New FLC 8N - Impressions Thread

[csglinux]

I agree with the comments of @EagleWings and @originalsnuffy as regards the 8D. It's a great headphone and probably deserves its own thread(?!). I actually managed to pick up an FLC8D for $200 some time ago, so maybe those sale prices are becoming more common? At that price, this is the bargain headphone of the century.

As for the comments about differences in the treble, mid-range, (bass?), etc., I think they're all potentially valid. The one slight issue I've found with the FLC range is that the tolerance isn't particularly tight. Here's my current FLC8S (with red/modded black/gunmetal filters and SpinFit Cp100 tips) and FLC8D (with gunmetal filters and SpinFit Cp100 tips), comparison of left and right channels:

These aren't too bad, but I've owned two pairs of FLC8N and neither had a channel balance this close. (I'm not going to publish those figures, but if you're interested in seeing some wild channel imbalance, send me a pm.)

I've spent a lot of time in the past worrying about tiny differences in FR (e.g., a modded black filter that attempted to split the difference between the gray and black low-frequency filters, and "borrowing" the dampers from the gold filters to double-filter my gunmetal filters in my FLC8N). My first pair of FLC8N had a much larger treble peak at 8.5 kHz than either of my previous pairs of FLC8S (see below). In my review of the FLC8N (search this thread for "FLC8S To FLC8N - Is It Worth Upgrading?": https://www.head-fi.org/showcase/flc-technology-flc-8n.23219/) I concluded that the FLC8N was more v-shaped than the FLC8S. That conclusion might have been skewed simply by the particular pair of FLC8N I had, because I recently obtained a second pair of FLC8N and this didn't have the same exaggerated peak at 8.5 kHz and its treble was much closer to that of my old FLC8S. The one thing I've seen consistently though in two pairs of FLC8N and my one pair of FLC8D is that the bass in the newer models is considerably more elevated than that in the FLC8S. This is the case even when using red/grey ULF/LF filters in the FLC8N and red/black ULF/LF filters in the FLC8S. I'm surprised that more people haven't noticed or mentioned that. But who knows - maybe this is also simply as a result of unit variance in the models I own??

There was an interesting comment recently on one of the InnerFidelity podcasts about how headphone samples sent to reviewers are typically made with tighter tolerances (and typically sound better) than the units that are eventually sold to the public. I know it's a tough job to maintain very tight tolerances and I don't want to bash FLC. But it's interesting to consider that folks could have different opinions on a headphone for reasons other than their own hearing and preferences. They might actually be listening to two very different-sounding headphones

With that being said, here are the averaged (L and R averaged over repeated measurements, all raw/uncompensated from a 711-compliant coupler using Cp100 SpinFit tips) of the FLC8S vs FLC8N vs FLC8D:

To clarify the legend here: FLC8S was measured with red/modded black/gunmetal filters; FLC8N was measured with red/gray/gunmetal filter and also red/gray/double-gunmetal filters; FLC8D was measured with the gunmetal filter. You can probably discount the cyan curve, because that large 8.5 kHz treble peak seemed to be an effect on my first pair of FLC8N which I did not see on my 2nd pair, nor do I see this effect on my FLC8D, which is just using the standard gunmetal filter in the measurements above.

Is there a difference in the mid-range from FLC8N to FLC8D? Maybe, but it's not as significant as variations from unit to unit. And it's nowhere near as significant as the low frequency differences going from FLC8S to either FLC8N or FLC8D.

I love the FLC8D's ergonomics (more so than that of the FLC8S) and their low frequency tuning is great - I really don't feel like I'm missing anything by not being allowed to tune down there. Not having those ULF and LF filters could be a blessing for another reason - there's less to go wrong. The reason I ended up with a second pair of FLC8N, was because the first pair developed a huge channel imbalance in the bass as a result of a small internal filter (the adhesive stick-on filter which is visible just below the opening for the LF filter) that came away. I hadn't done anything other than change the LF filter a coupler of times, but that internal adhesive stick-on bass-port filter came away and got lost inside the IEM and I wasn't able to fix it. (LMUE were good about replacing it, although they don't win any prizes for being quick to respond to email - it took a month to get them replaced.) The change in bass from that of the old FLC8S looks large, but I was a big fan of the Monster Turbine Coppers that had even more sub bass than the FLC8N/FLC8D. I do enjoy a pounding sub-bass, so I feel the FLC8D is a step-up in that regard.

I can't think of any other earphone in the $200 price range that can compete with headphones like the SE846, Xelento or KSE1500. Come to think of it, there's not much else I'm aware of in the <$1000 range that competes with these headphones.
FLC8D is a great headphone even at MSRP. At $200, it's a fantastic bargain

 

[nghiatran139]

I've been really enjoying the FLC 8D. Just for future references, do you guys think that the Andromeda or the U12t would be a big step up in SQ? I've heard raving reviews about those two and I am considering them as a potential upgrade.

Edit: Typo

 

[csglinux]

I've been really enjoying the FLC 8D. Just for future references, do you guys think that the Andromeda or the U12t would be a big step up in SQ? I've heard raving reviews about those two and I am considering them as a potential upgrade.

Edit: Typo

I haven't spent much time with the U12t, so I'll defer to others on that. (But IMHO, all 64 Audio products are priced way beyond their performance level.) As far as the Andromeda goes, its ergonomics and comfort are just horrible. Is it worth suffering the pain of that stupidly designed Andromeda shell? IMHO, no:

Andromeda is marginally flatter throughout the midrange, but its treble extension is no better than that of the FLC8D. The problem with the Andromeda's FR is the slightly heavy mid bass. The FLC8D rises all the way into the sub-bass (as it should), whereas the Andromeda rolls off there like a cheap pair of Beats by Dr. Dre headphones. I personally wouldn't choose the Andromeda over the FLC8D even if the Andromedas were free.

 

[WhatToChoose]

I haven't spent much time with the U12t, so I'll defer to others on that. (But IMHO, all 64 Audio products are priced way beyond their performance level.) As far as the Andromeda goes, its ergonomics and comfort are just horrible. Is it worth suffering the pain of that stupidly designed Andromeda shell? IMHO, no:



Andromeda is marginally flatter throughout the midrange, but its treble extension is no better than that of the FLC8D. The problem with the Andromeda's FR is the slightly heavy mid bass. The FLC8D rises all the way into the sub-bass (as it should), whereas the Andromeda rolls off there like a cheap pair of Beats by Dr. Dre headphones. I personally wouldn't choose the Andromeda over the FLC8D even if the Andromedas were free.

Could you please elaborate on your opinion of 64 Audio's poor price to performance ratio? I have been eyeing their IEMs as a potential future purchase, and I would like to hear your thoughts

I like reading thoughts of people who cut through the hype

 

[EagleWings]

I'll start off by saying Andromeda and U12t offer improvements in non-tonal aspects such as transparency, soundstage, instrument separation, layering and imaging precision. All these translate to an improved sense of refinement and realism. But as you move up the pricing ladder, the law of demising returns gets stronger, so only you can answer questions like, "is the improvement in finesse worth the price difference?".

(All comparisons with the 8D below are using the Gold filter)

Andromeda has a bit of a mainstream tuning that is difficult to hate. Good bass, linear midrange and an articulated treble. And to top it all off, it has a large sound stage. With the 8N you could almost mimic Andro's tuning, but with the 8D, the bass becomes fixed, so you can't. In terms of tuning, there are some aspects I prefer on the 8D and some aspects I prefer on the Andro. For example, in the bass, you really want your IEM to plateau below 100Hz, else the sub-bass will start dominating the bass. So I prefer the Andromeda's bass there. In the midrange, you really start to hear the refinement of the Andro, with the vocals and instruments having a sense of realism that the 8D can't quite reproduce. But Andro's upper mids are a bit lacking compared to the 8D as you can see in the above graph. In fact 8D's upper mids are already a toned down a touch. While the graph shows 8D's lower treble peak to be higher, Andro's will come across as sharper, as you'd tend to crank the volume up on the Andro slightly to hear the upper-mids. Despite being sharper in the treble, Andro's transition from upper-mids to the treble is more linear and effortless, which is one of the reasons for its success. Anything beyond 8kHz you see in the graph is shot in the dark, because it won't really represent what you hear. If you could make a coupler with same biological material as your ear and to the exact dimensions of your ear canal, then you would get close. So don't trust the graphs for reading the upper treble. Why I say this is, to my ears, Andro has a better treble extension than the 8D, although the above graph suggests otherwise. And the better treble extension of the Andro is what adds to the refinement. Andro also has a slightly larger stage than the 8D, but the difference is not huge as the 8D's stage is already large.

Verdict: If I owned an Andro, I'd pick it any day over the 8D, but I would EQ it to add some upper mids and tone down the treble. I'd also be careful about matching the right source with the Andro, as its tonality can shift based on the output impedance of the source. While many people prefer an output impedance of 2-3Ohms for the Andro as it opens up the treble more, I prefer a lower OI as it helps keep the treble in check. But what do not want to do is match it with sources that have 4Ohm or larger OI.

U12t also has a bit of a mainstream tuning, but its tuning is focussed on bass and upper treble. With the M20 Apex module, it would have a stronger bass than the 8D. With the M15 module, it would be more in line with the 8D and I prefer the M15. What you'll hear is a slightly more nuanced and layered bass compared to the 8D. Just like on the Andro, the mids will come across with more refinement. U12t would have a slightly thicker lower-mids which gives power to male vocals and certain instruments. 8D sounds more kenaf on the other hand and as a result, it gives equal weightage to all instruments. U12t also has a bit of a toned down upper-mids. In the treble, because the U12t uses a Tia driver, its treble sounds a little different from the treble of most IEMs. It sounds more open and more articulated. U12t also has a lower treble peak, but it will be smoother than the 8D. The biggest difference will be the upper treble (>10kHz). Tia drivers have this ability to have unmatched treble extension. This results in improvement in imaging precision and separation layering. But the upper-treble is a bit too boosted for its own good. Because, in the process of improving some of the non-tonal aspects, it kind of kills the timbre of instruments by sounding a little etchy. But it's not as bad as on the Tia Fourte. Also, the soundstage that the U12t presents is larger, more open and a bit holographic compared to 8D's stage.

Verdict: If I owned a U12t, I'd pick it any day over the 8D. While I don't have to worry about the impedance issue like the Andro, I'd still do some EQ. I would agree with csglinux that 64Audio has been too greedy with their pricing. If you can find a used unit for $1000, it would be great. But I think the more realistic price in the used market for the u12t is $1400-$1600.

Bottomline: 8D is a great IEM for its price and nothing more and nothing less. It can't compete with the big boys IEMs in terms of non-tonal aspects and refinement. But like I said, for $200 its an awesome product.

P.S: One more aspect that you would notice with the Andro and U12t is, the instruments that are placed far from you would sound more transparent and you'd be able to at least guess what instrument t might be. Where as on the 8D, even though it can place the instrument that far from you, it would just sound as a musical note, but it would be more difficult to discern what instrument it is.

 

[originalsnuffy]

Seems to me that there should be a thread specifically for the 8D. It really offers a level of price to performance that is hard to beat and I bet very few head fi readers have any awareness of how good this unit is. There is tremendous interest in the ibasso IT01s for example; which is the same effective price. Now I have the it01 and while its great at its price point I doubt the s version is $100 better compared with the 8D.

 

[WhatToChoose]

I'll start off by saying Andromeda and U12t offer improvements in non-tonal aspects such as transparency, soundstage, instrument separation, layering and imaging precision. All these translate to an improved sense of refinement and realism. But as you move up the pricing ladder, the law of demising returns gets stronger, so only you can answer questions like, "is the improvement in finesse worth the price difference?".

(All comparisons with the 8D below are using the Gold filter)

Andromeda has a bit of a mainstream tuning that is difficult to hate. Good bass, linear midrange and an articulated treble. And to top it all off, it has a large sound stage. With the 8N you could almost mimic Andro's tuning, but with the 8D, the bass becomes fixed, so you can't. In terms of tuning, there are some aspects I prefer on the 8D and some aspects I prefer on the Andro. For example, in the bass, you really want your IEM to plateau below 100Hz, else the sub-bass will start dominating the bass. So I prefer the Andromeda's bass there. In the midrange, you really start to hear the refinement of the Andro, with the vocals and instruments having a sense of realism that the 8D can't quite reproduce. But Andro's upper mids are a bit lacking compared to the 8D as you can see in the above graph. In fact 8D's upper mids are already a toned down a touch. While the graph shows 8D's lower treble peak to be higher, Andro's will come across as sharper, as you'd tend to crank the volume up on the Andro slightly to hear the upper-mids. Despite being sharper in the treble, Andro's transition from upper-mids to the treble is more linear and effortless, which is one of the reasons for its success. Anything beyond 8kHz you see in the graph is shot in the dark, because it won't really represent what you hear. If you could make a coupler with same biological material as your ear and to the exact dimensions of your ear canal, then you would get close. So don't trust the graphs for reading the upper treble. Why I say this is, to my ears, Andro has a better treble extension than the 8D, although the above graph suggests otherwise. And the better treble extension of the Andro is what adds to the refinement. Andro also has a slightly larger stage than the 8D, but the difference is not huge as the 8D's stage is already large.

Verdict: If I owned an Andro, I'd pick it any day over the 8D, but I would EQ it to add some upper mids and tone down the treble. I'd also be careful about matching the right source with the Andro, as its tonality can shift based on the output impedance of the source. While many people prefer an output impedance of 2-3Ohms for the Andro as it opens up the treble more, I prefer a lower OI as it helps keep the treble in check. But what do not want to do is match it with sources that have 4Ohm or larger OI.

U12t also has a bit of a mainstream tuning, but its tuning is focussed on bass and upper treble. With the M20 Apex module, it would have a stronger bass than the 8D. With the M15 module, it would be more in line with the 8D and I prefer the M15. What you'll hear is a slightly more nuanced and layered bass compared to the 8D. Just like on the Andro, the mids will come across with more refinement. U12t would have a slightly thicker lower-mids which gives power to male vocals and certain instruments. 8D sounds more kenaf on the other hand and as a result, it gives equal weightage to all instruments. U12t also has a bit of a toned down upper-mids. In the treble, because the U12t uses a Tia driver, its treble sounds a little different from the treble of most IEMs. It sounds more open and more articulated. U12t also has a lower treble peak, but it will be smoother than the 8D. The biggest difference will be the upper treble (>10kHz). Tia drivers have this ability to have unmatched treble extension. This results in improvement in imaging precision and separation layering. But the upper-treble is a bit too boosted for its own good. Because, in the process of improving some of the non-tonal aspects, it kind of kills the timbre of instruments by sounding a little etchy. But it's not as bad as on the Tia Fourte. Also, the soundstage that the U12t presents is larger, more open and a bit holographic compared to 8D's stage.

Verdict: If I owned a U12t, I'd pick it any day over the 8D. While I don't have to worry about the impedance issue like the Andro, I'd still do some EQ. I would agree with csglinux that 64Audio has been too greedy with their pricing. If you can find a used unit for $1000, it would be great. But I think the more realistic price in the used market for the u12t is $1400-$1600.

Bottomline: 8D is a great IEM for its price and nothing more and nothing less. It can't compete with the big boys IEMs in terms of non-tonal aspects and refinement. But like I said, for $200 its an awesome product.

P.S: One more aspect that you would notice with the Andro and U12t is, the instruments that are placed far from you would sound more transparent and you'd be able to at least guess what instrument t might be. Where as on the 8D, even though it can place the instrument that far from you, it would just sound as a musical note, but it would be more difficult to discern what instrument it is.

Awesome writeup man, extremely informative and helpful. Thanks

I guess if I ever get 64audio, B stock is the way to go at best

 

[silvahr]

I haven't spent much time with the U12t, so I'll defer to others on that. (But IMHO, all 64 Audio products are priced way beyond their performance level.) As far as the Andromeda goes, its ergonomics and comfort are just horrible. Is it worth suffering the pain of that stupidly designed Andromeda shell? IMHO, no:



Andromeda is marginally flatter throughout the midrange, but its treble extension is no better than that of the FLC8D. The problem with the Andromeda's FR is the slightly heavy mid bass. The FLC8D rises all the way into the sub-bass (as it should), whereas the Andromeda rolls off there like a cheap pair of Beats by Dr. Dre headphones. I personally wouldn't choose the Andromeda over the FLC8D even if the Andromedas were free.

Thank you for the information. It was very useful since I had the Andromeda for about 18 months and now I can compare.
I'm almost pulling the trigger based on what I read from you (don't want to turn you in an "opinion maker" but I really like the way you put the things and your integrity).
I wonder how the FCL8D compare to Etymotic ER4XR. Do you have some information about that?
Thank you in advance.

 

[csglinux]

Could you please elaborate on your opinion of 64 Audio's poor price to performance ratio? I have been eyeing their IEMs as a potential future purchase, and I would like to hear your thoughts

I like reading thoughts of people who cut through the hype

PM on its way to you shortly...

@EagleWings - good, comprehensive set of impressions there! Obviously our preferences are different (and you're using gold filters and I'm using gunmetal). I agree with you that the overall sound of the Andromeda is pretty good. I'd say disappointingly good. Disappointing in the sense that you have to suffer extreme torture from the stupidly-designed outer shell in order to listen to it. Unlike you, however, I do not prefer the overall sound of Andromeda to the FLC8D. (And I'm not shilling. If you've read my previous posts here and my review of the FLC8N you'll see I've not been shy of criticising FLC in the past.) There are loads of points to discuss here, but briefly (or as brief as I can be!):

1) I think the "treble extension" that people appear to perceive with the Andros is simply that they have an overall brighter sound signature by virtue of a rolled-off bass and slightly recessed mids (which you'll definitely see after applying a diffuse-field compensation). The perception of these couplers not being reliable beyond 10 kHz is I think largely due to the fact that the 711 standard only has specifications for the input and transfer impedance up to that point. But the mics are typically ruler flat all the way out to 20 kHz, and there's no indication that anything below 10 kHz really matches the average human ear anyway. It likely represents somebody's ear, but that might not be you or I. The newer (and badly-named) "hi-res" couplers do nothing but add a half-wave resonance damping to make THD measurements look better; there is zero evidence they offer any more physical realism than standard 711 couplers above 10 kHz. You can be fairly confident that the Andromedas do roll off just beyond 9 kHz. Campfire Audio's own measurements of the Andromeda show the exact same behavior, and I have plenty of other IEMs that don't roll off this early, so this isn't a limitation of the coupler or mic.

2) As for transparency, soundstage, layering, instrument separation, rhythm, refinement, realism and other such nebulous things... If you take a frequency sweep and capture amplitude and phase, you can reconstruct everything about the IEM, including phenomena like transient square wave or impulse response. I don't discount the possibility there's some aspect of the sound we aren't yet prioritizing in our analysis, but unless and until we discover that magical 5th dimension, I don't know what else there can be that differentiates these headphones. I never underestimate placebo effect - especially on my own limited brain. When reproducing sound recorded on stage mics for playback on stereo speakers, an expansive soundstage via any headphone can be, at best, a cheap illusion. Playback through something like a Smyth realizer is needed to correctly account for soundstage.

3) No worries if anybody else prefers a rolled-off bass. There's no right or wrong in terms of subjective preference. But in terms of equal loudness, I would argue FLC8D is right and the Andros are, well, too rolled-off:

https://en.wikipedia.org/wiki/Equal-loudness_contour

... and I shouldn't have to apply EQ to a $1000+ headphone

4) THD tends to measure very similarly for all these BA-based (or hybrid BA) IEMs.

P.S: One more aspect that you would notice with the Andro and U12t is, the instruments that are placed far from you would sound more transparent and you'd be able to at least guess what instrument t might be. Where as on the 8D, even though it can place the instrument that far from you, it would just sound as a musical note, but it would be more difficult to discern what instrument it is.

5) That's possible. A flatter mid-range at the eardrum would tend to better preserve the ratio of the relevant harmonics and so the timbre of individual instruments. But note the "at the eardrum" part. That's going to vary from individual to individual according to anatomy and the proportion of the ear canal occluded by the IEM. In my experience, the amount of mid-range (~3-4 kHz) bump preferred to give the correct timbre can have wild variations from person to person (see for example here: https://www.head-fi.org/threads/rha-cl2-tuning-preferences.894595/) so it's difficult to extrapolate this conclusion to others.

6) At least for me, the Andromedas are really, really uncomfortable to wear. But auditioning headphones yourself is the only way you'll ever really know for sure about the fit and the sound.

Seems to me that there should be a thread specifically for the 8D. It really offers a level of price to performance that is hard to beat and I bet very few head fi readers have any awareness of how good this unit is. There is tremendous interest in the ibasso IT01s for example; which is the same effective price. Now I have the it01 and while its great at its price point I doubt the s version is $100 better compared with the 8D.

I agree. It's a shame to bury it in another thread. Maybe @Flcforrestwei could change the title of this thread to include FLC8d?

 

[nghiatran139]

Thank you for the informative write-ups! I really appreciate it.

 

[csglinux]

Could you please elaborate on your opinion of 64 Audio's poor price to performance ratio? I have been eyeing their IEMs as a potential future purchase, and I would like to hear your thoughts

I like reading thoughts of people who cut through the hype

Ok, I was going to send you a pm, but I can't because of your privacy settings. Ok, so I'll try to tame this down a bit and cut through a bit less hype

Here's my take on 64 Audio.

The issue is primarily how one determines product pricing. You can figure out your R&D, manufacturing, distribution and marketing costs and add a reasonable profit margin. Or... you can simply charge the maximum price you think the market will tolerate. It doesn't take Einstein to figure out which of those two camps 64 Audio sit firmly in.

And 64 Audio products are really nothing extraordinary. They use standard off-the-shelf components that you can buy for pennies from sites like mouser.com or diyearphone.com. TIA (tubeless in-ear audio) is what many other manufacturers have been doing for ages. FLC, Campfire Audio, Beyerdynamic, Sennheiser, Shure, etc, don't make a song and dance about it or charge a 1000% mark-up for it. A couple of $0.50 balanced armatures without a driver tube doesn't justify a $3500 price tag.

And then there's the even sketchier side of their business. 64 Audio came to prominence during a collaboration with Stephen Ambrose. They licenced his 'ADEL' module (the Ambrose Diaphonic Ear Lens). The claim was that this device protected your hearing by limiting your exposure to 'pneumatic pressure'. In hindsight, this is almost comical. Anyway, here is the background...

The sound pressure level at your eardrum is just a function of the normal stress imparted by the motion of the air molecules against your eardrum (tympanic membrane). Those air molecules create a force, which - if different from the pressure on the other side of your eardrum - creates a net force causing the eardrum to move, in turn moving the fluid and cilia in the inner ear and registering sound in your brain. Ambrose made a big deal about a mechanism called the stapedius reflex, which causes the tympanic membrane to tighten and protect the cilia against loud sound - and even occlusion noise when you vocalize. This is a good evolutionary trait because current science knows no way to regenerate the cilia once you lose them.

When you insert an IEM (or put on an over-ear can), your eardrum should be maintained at equilibrium - in other words, in an ideal world nothing should happen just by putting on a pair of headphones that causes you to experience compression (pressure) or expansion (vacuum). With well-sealing tips on non-ported IEMs, it is possible to push the tip in far enough to create a seal, and then further still to raise the mean pressure on the eardrum, or conversely, create a seal and then have the IEM tug slightly due to the weight of the cable, creating what some call a vacuum seal. This might be slightly uncomfortable, but it's very unlikely to be harmful unless you're jamming or yanking your IEMs in and out of your ear canals extremely quickly. Inserting an IEM creates only a tiny fraction of the mean pressure difference you'd experience if you went on a plane or dived a few feet underwater. You can always equalize that pressure again by swallowing or yawning. It's often a good idea to open your jaw when inserting an IEM and then you'll never have this issue anyway.

What is going to adversely affect your hearing long term are large sustained oscillatory motions of the cilia. I'll agree with Ambrose that we all want to avoid that because we want to protect our hearing.

So far so good. Here's the problem with the ADEL marketing. They claim there's this terrible thing called "pneumatic pressure". This is garbage. There is simply no such thing. Pressure is pressure - the same normal force created by the same molecules. An increase in pressure simply means you've squeezed more air molecules into the same space at the same ambient temperature. Ambrose's video illustration of a garden hose being held with a thumb over the end shows a complete ignorance of fluid mechanics. Water flow in a garden hose is a fixed mass-flow rate of an essentially incompressible fluid. Air is compressible and there is no mechanism in dynamic, balanced armature, planar magnetic, electrostatic or any other acoustic driver to create a constant flow rate or a net (mean) pressure shift. That is simply not how headphones work. All headphones are zero net-mass-flow oscillators.

Now imagine the following. Imagine you have a driver in a tube which splits or forks into two identical tubes. At the end of one is your eardrum; at the end of the other is the ADEL membrane. Let's first imagine that the structural response of the ADEL membrane is identical to that of your eardrum. (And the pressures are already the same on the other side of both, since your eustachian tube will be at ambient pressure.) Now we'll move the driver with a sound source. We can express the driver motion as A.cos(B.t+C), where A is the amplitude, B is the frequency and C is a phase shift. Both eardrum and ADEL membrane move in sync because we have a perfectly symmetrical setup. Let's call this IEM 1:


Now consider IEM 2. In IEM 2, I have a setup which is exactly half of IEM 1. Let's say I couldn't afford an ADEL module, so I have just half a driver tube which runs to only one secondary tube that goes directly to my eardrum. So the first scenario (IEM 1) is completely symmetric with the driver tube splitting and running to two identically-responding eardrums/membranes. Again, I'm going to move the driver in IEM 2 with the exact same A.cos(B.t+C) motion. What do I hear differently from IEM 1? Absolutely nothing. Mathematically, the two scenarios create absolutely identical responses at the eardrum. The only difference is IEM 2 is moving a driver that has half the area of IEM 1, so it's simply moving half the amount of air and needing a lower power, i.e., a lower volume. That is absolutely the only difference.

Now let's consider what happens in IEM 1 if you use a nicely compliant membrane (one which is structurally less rigid and more flexible than the eardrum) to absorb all those nasty "pneumatic pressures". What happens now? Well, yes, to some degree, one could argue it will "protect your hearing", because if the membrane can flex more easily than your eardrum, it would somewhat lessen the SPL measured at the eardrum. But you would simply perceive this as a quieter sound - and most people would just turn up the volume to compensate. And there's a problem, because this membrane is now responding to the pressure forces at a different rate to that of your eardrum; the acoustic waves in the two tubes are no longer symmetric and you're going to get phase errors and comb-filtering interference effects between the two. Also, you're now peak-limiting the loudest sounds, which adds a second form of signal distortion - and depending on the membrane properties, you're more likely to be preferentially peak-limiting the lower frequencies, which will also skew the overall frequency response. (Peak-limiting is what sketchy mastering engineers do to win the loudness wars by adding compression and limiting the useful dynamic range for folks that need uniformly-loud pop music.) If you really want to peak limit, that can be done in software too, but using a mechanical or software device to peak limit are both terrible ideas. There's a much better way of saving your ears which won't degrade your audio signal with clipping, limiting or phase-errors and interference effects - just turn your volume down.

Best case scenario, the ADEL module has done nothing but empty your wallet. Unfortunately, the most likely scenario is that it's also been slightly degrading your sound quality while doing nothing to protect your hearing that you couldn't have achieved much more easily by simply listening at a safe volume.

At some point 64 Audio and Ambrose decided they wanted to part ways. There was a fair amount of skepticism in the community about ADEL (and rightly so), which might also have played a role. But 64 Audio didn't abandon this potential revenue stream - they just created some new nonsense of their own that would be even more profitable, as they wouldn't need to pay licensing fees for it. So these days you're also paying extra for an APEX module.

APEX and ADEL are both snake oil solutions to a problem that doesn't exist, and yet another potential source of error to the acoustic signal reaching the eardrum. I guarantee the 64 Audio folks are smart enough that they already know all this. So the fact that they continue to push it shows they're disingenuous. I would avoid 64 Audio like the plague. They are amongst the worst value-for-money audio products you can buy right now.

I wonder how the FCL8D compare to Etymotic ER4XR. Do you have some information about that?

I also own (and like) the ER4XR

Etys are the kings of isolation, but to get that isolation you really need to use something like Comply foam tips, which tend to roll off the treble. They're very different headphones from the FLC8D - they have a much heavier mid-range boost and a relatively anemic bass. The argument for the Ety mid-range bump is that they should look pretty much flat after a diffuse-field correction, but as I mentioned above, whether that works for you or not will depend on your own ear canal anatomy, and according to those equal loudness curves, flat is actually not what you want anyway. I use the Etys for their isolation in a noisy environment, but in every other situation I'd choose the FLC8D. Hope that helps!

 

[silvahr]

I also own (and like) the ER4XR



Etys are the kings of isolation, but to get that isolation you really need to use something like Comply foam tips, which tend to roll off the treble. They're very different headphones from the FLC8D - they have a much heavier mid-range boost and a relatively anemic bass. The argument for the Ety mid-range bump is that they should look pretty much flat after a diffuse-field correction, but as I mentioned above, whether that works for you or not will depend on your own ear canal anatomy, and according to those equal loudness curves, flat is actually not what you want anyway. I use the Etys for their isolation in a noisy environment, but in every other situation I'd choose the FLC8D. Hope that helps!

Thank you very much!
Order made! Should have them Friday!

 

[csglinux]

Thank you very much!
Order made! Should have them Friday!

I'm sure you'll love them!

 

[originalsnuffy]

In my early days of portable audio I did own some ETYs. I found then uncomfortable. You had to put them way up the ear canal.

The sound to me was kind of dry and uninspiring. But to each their own.

 

[silvahr]

I have the ER4XR and I really like them. I can't describe the sound but to me everything sounds in the right place using CH2 as source.
I had no problems in let Andromeda go and keep the ETYs.
I'm not saying ETYs are better than Andromeda but I can live very well with the ETYs and couldn't justify the price gap.
Regarding confort and from my own experience, I prefer the ETYs over Andromeda.
Sure there are other IEMS much more confortable (Earsonics ES5 for instance) but I tolerate the ETYs very well. First was a bit difficult but now I don't have any problem.
My aim in get FLC 8D it's have an IEM with merits, very different from ER4XR and with the bonus of being customizable for diffent moods. Probably will be more confortable then ETYs and Andromeda which is another bonus.
The posts of @csglinux made my mind.