Hiby FC3 Review – Portability is Key

Sound –

Frequency Response –

Testing Methodology: RMAA via Startech External Sound Card

The FC3 offers a linear frequency response suggesting that it represents audio with great fidelity. Due to the quality of my sound card, I am unable to reliably test other measures such as distortion and crosstalk so they will be used as a personal reference only. Qualities here can also impact the sound as I will detail via subjective listening.

Output Impedance & Hiss –

Testing Methodology: SPL volume matched comparison through an inline splitter to THX789 + SMSL SU9 to Campfire Audio Ara

Hiby do not state the output impedance nor does ESS quote a figure on their website so I established a rough figure empirically. As always, best practice dictates that the output impedance should be 1/8^th of the impedance of the attached gear unless otherwise stated by the manufacturer. This is especially pertinent on multi-driver earphones where you can experience a significant change in the frequency response. To assess this, I used an in-line splitter between the FC3 and my THX 789 desktop amp (1-ohm) both connected to the CFA Ara which sports a mechanical crossover and super low 8.5-ohm impedance making source selection especially critical.

This earphone can also discern sub 1-ohm output impedance which appears to be the case here, as the Ara was slightly fuller and smoother from the FC3 even compared to the THX789 – a result consistent with my other sub 1-ohm sources. I did hear a very slight background hiss with the Ara. This was not present on less sensitive IEMs, but on especially sensitive models, some noise will be evident for low-volume listeners. Still, it is fairly innocuous once music is playing. Overall, this makes the FC3 a strong choice for low-impedance multi-driver IEMs. The slight hiss is something to consider if you’re a quiet listener though is unlikely to affect the vast majority, especially those with less sensitive IEMs.

Subjective –

New ESS sources tend to be characterised by a neutral and linear sound, though of course, some manufacturers intentionally add their own colouration which varies by implementation. This does not seem to be Hiby’s intentions, as the FC3 delivers a dead neutral tone and presentation that is well-balanced across the board. There is nothing that really stands out to the listener and, similarly, the note presentation is rather innocuous so the properties of the attached gear shines to the fore.

Bass has good extension, a little less sub-bass weight and slam than a more powerful source but a tight kick nonetheless. Mid-bass has a lick of emphasis that brings back some fullness, retaining a natural and balanced presentation overall. The tone is just a touch warm and the texture slightly smoother than neutral. My desktop source was more controlled, delivering a more composed and defined representation while the FC3 was balanced and tactile but skipped over some fine textures in complex tracks.

The midrange too is characterised by good linearity and an accurate timbre overall. It very much resembled my D70s + THX789 combo with great tonal transparency and accurate positioning. Vocal size was a smidge reduced on the FC3, contributing to a slightly less powerful sound. However, layers remains well-defined and delineated, similarly, instruments were flattered by the uptick of low-end fullness and accuracy through the midrange itself.

Treble tells a similar story showcasing minimal colouration here too. If anything, the FC3 sounds very slightly smooth in the foreground but with a hint of upper-harmonic lift granting a slightly crisp instrument representation. There remains a good amount of body and fine detail retrieval is strong. This isn’t an especially aggressive source as past generation ESS sources could be, so you get a natural, nicely refined and textured treble instrument portrayal. Extension as well is admirable, the background is clean and offers good contrast, there’s nice resolution of background details that adds some dimension to the presentation as well. Of course, the FC3 won’t touch a larger, higher-end source yet alone a good desktop stack, though it isn’t a sound that is overtly lacking in any regard either.

The soundstage presentation is likely most suggesting that this is a portable source, as it simply doesn’t expand like a higher-end or larger source. The FC3 has a relatively intimate presentation that extends just beyond the head in terms of width and is equally limited in depth. There are a few portable sources that provide noticeably wider presentations, though they do come in slightly more expensive. Imaging is sharp, however, aided as well by the linear signature. Though it isn’t especially multi-dimensional, the presentation has great separation and excellent layering that upholds good coherence and organisation.

Driving Power –

Lime Ears Pneuma: The Pneuma is an efficient multi-driver earphone that is almost source agnostic regarding impedance. The FC3 does a good job here, delivering a balanced sound similar to my desktop stack. Bass had good extension with some pressure and decent control. My desktop stack had noticeably more power and was more controlled through the mid-bass especially, with greater separation. Otherwise, the FC3 was faithful and well-detailed. The soundstage was narrower with less accurate coronal positioning but great separation and layering. The FC3 introduced zero background hiss. This kind of surely where the FC3 most feels in its element.

Final E5000 (93dB, 14ohm): The E5000 has an especially low sensitivity for an IEM making it more demanding of the source than most. My desktop stack had a more powerful sub-bass and also greater control, yet the FC3 offered impressive cleanliness in the bass nonetheless with its linear voicing and decent mid-bass speed. The midrange was also quite coherent and well-defined. The treble was natural with good headroom. I found the soundstage to be markedly narrower than the desktop stack though depth remained quite good, separation was also impressively close between the two despite the reduction in expansion. The FC3 introduced zero background hiss here too.

Audeze LCD-X (103dB, 22ohm): The LCD-X is a relatively easy to drive full-size planar headphone but scales very well with resolving sources. The FC3 did an admirable job in terms of volume and provided just enough current to retain a balanced sound signature. Bass was diminished relative to my desktop stack, especially sub-bass which had noticeable roll off. The midrange remains pretty even and coherent, so did the treble, though there was less sparkle than my desktop stack. The soundstage followed suit, being narrower but upholding defined layers and sharp imaging. I feel more output power would have benefit this pairing.

Suggested Pair-Ups

The FC3 has relatively high gain meaning that volume was almost always sufficient for my preferences, even on medium impedance full-size headphones such as the Focal Clear. Similarly, it had enough fine volume control for sensitive IEMs which enhances versatility. Of course, being USB powered, power output is inherently limited to around 70mW per channel which is about on par with most competitors in this category. In turn, the FC3 doesn’t provide a whole heap of sub-bass physicality, especially noticeable on less sensitive gear. Otherwise, the FC3 is a great choice for essentially all IEMs and portable headphones while sufficing for some full-size models in the double-digit impedance range especially.

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