Fit and Comfort

Seen above is the right channel of the Truthear Hexa placed into an artificial ear mold with the included smaller bore size M silicone ear tip installed. I have average-sized ears, and the ear mold above represents my own experiences well enough as a proxy. Size M silicone tips are my go-to for testing, since foam tips are not included by some brands. The relatively thick nozzle can be a deterrent to some, but was fine for me. I also appreciated the longer, angled nozzle that went into the ear canal enough to allow the shells to rest in the concha properly, without protruding out much since these are somewhat thick throughout. The shell curvature has several points of contact in the ear concha for added support, with the ergonomic shape working well. They also weigh less than average at ~6 g each, thus preventing physical fatigue. The pre-formed ear hooks can be hit-or-miss, and an angled housing for the 2-pin connectors would have come in handy as a fail-safe should you have to re-form them. The single vent and the good fit achieved here resulted in an excellent seal for me, which in turn means great passive noise cancellation too.

Audio Performance

Audio Hardware

Remember that 10 mm dynamic driver the Truthear ZERO used? It's re-used in the Hexa, all the way down to the same liquid crystalline polymer (LCP) composite diaphragm and polyurathane (PU) surround/suspension. With the ZERO, this driver worked exclusively as sub-woofer handling although here Truthear mentions the bass as a whole is catered to by this driver. There are then two sets of custom balanced armature drivers in the form of a dual BA for the mids and a single BA unit for the higher frequencies. These do not seem to be actual Knowles drivers but are based off equivalent versions anyway, especially given the Knowles-style BA dampers used in the nozzle. Going with a different driver source helps Truthear cut down on the materials used in the Hexa and, in turn, the product cost itself. Time will tell how well these fare in practice, but the bottom line is these come together to make for a pair of IEMs that are slightly more demanding in power compared to an average set of IEMs, owing to a combination of a 20 Ω rated impedance and a sensitivity of 120 dB/Vrms that corresponds to 103.1 dB/mW. This still means that the Truthear Hexa is easy enough to run off a decent dongle, let alone portable DAC/amps with more features and power output.

Frequency Measurement and Listening

I will mention that I have a general preference for a warm-neutral signature with a slightly elevated bass, smooth treble range, detailed mids, and good tonal separation. I also generally prefer instrumental music over vocals, with favored genres including jazz and classical music.


Our reproducible testing methodology begins with a calibrated IEC711 audio coupler/artificial ear that IEMs can feed into enough for decent isolation. The audio coupler feeds into a USB sound card, which in turn goes to a laptop that has ARTA and REW running and the earphones connected to the laptop through the sound card. I begin with an impulse measurement to test for signal fidelity, calibrate the sound card and channel output, account for floor noise, and finally test the frequency response of each channel separately. Octave smoothing is at the 1/12th setting, which nets a good balance of detail and noise not being identified as useful data. Also, the default tuning was used for testing, and no app-based settings were chosen unless specifically mentioned. Each sample of interest is tested thrice with separate mounts to account for any fit issues, and an average is taken of the three individual measurements for statistical accuracy. For IEMs, I am also using the appropriate ear mold fitted to the audio coupler for a separate test to compare how the IEMs fare when installed in a pinna geometry instead of just the audio coupler. The raw data is then exported from REW and plotted in OriginPro for easier comparison.


The IEC711 is such that you can't really compare these results with most other test setups, especially those using a head and torso simulator (HATS). The raw dB numbers are also quite contingent on the set volume, gain levels, and sensitivity of the system. What is more useful information is how the left and right channels work across the rated frequency response in the Truthear Hexa. The left channel was separately tested from the right one, and colored differently for contrast. I did my best to ensure an identical fit for both inside the IEC711 orifice, so note how the two channels are practically identical across the entire useful 20 Hz to 20 kHz range! The measured discrepancy from 5-8 kHz is a measurement artifact that comes out of matching the coupler resonance to 8 kHz, and in practice a proper deep fit had the resonance hit closer to 9 kHz on my coupler, at which point the two channels were spot on, meaning in your ears they will be identical too. This is a randomly picked retail unit sent from the SHENZHENAUDIO warehouse, so I am very happy with what I saw and heard here, even though I must point out that a few other review units did exhibit channel imbalance in the bass itself. Measurements taken after 25 hours of testing, which included these playing a mix of various songs as well as white or pink noise and sine sweeps, showed no difference. There was no perceived burn-in effect thus, and none was measurable, either. The response with the anthropomorphic pinna in place matched the ideal scenario in the coupler quite well too, especially if you consider that anything after the coupler resonance point is best taken with a grain of salt, which is an indicator of how good the seal was when installed in the artificial ear.


Here is the average frequency response for both channels of the Truthear Hexa plotted against my personal target taken from VSG.squig.link, which also gives you an idea of my personal preferences to better correlate any possible biases. The tuning of a set of headphones or earphones does not have to match my target as long as it is tuned with some direction, makes sense, and is executed well. After all, no one set will appeal to everyone, and having different options is what makes this hobby so interesting and hard to quantify. Truthear's goals with the Hexa include a more natural yet punchy bass presentation, clear highs (with the silicone tips), no phase distortion throughout the frequency range, and a generally smooth transition between the drivers while still catering to HRTF preferences.

There is no Truthear target at this point and it's obvious the Hexa is tuned differently from the ZERO. Indeed, while the latter was clearly aiming for the Harman 2019 v2 in-ear target, the Hexa goes for a more warm neutral presentation that I personally like more—should be obvious given the tonality matches my target well enough! It's weird to see this come about again after seeing so many similar sets an year ago, followed by almost everyone trying to go the Harman route. The Hexa has ~6.5 dB rise in the sub-bass relative to the lowest spot in the mids at ~700 Hz, and this can feel somewhat weak for those wanting a more pronounced bass response. Yet, it's good bass quality in also being plenty dynamic and allowing you to discern between notes playing at different volumes. The same driver relegated to the sub-bass in the Truthear ZERO does well also in the mid-bass here, allowing for decent impact of drums and bass guitar strums. The Hexa also takes fairly well to EQ, and really the presentation is appealing to me.

This continues with the mids too courtesy a fairly smooth crossover to the balanced armature drivers, although I immediately noticed the so-called BA timbre in play here. In particular, string instruments came off slightly plasticky to me and it was also not the easiest to distinguish bassoon notes in some of my favorite jazz tracks. I can only speculate whether it's the actual driver quality that's keeping the potential of the Hexa down, although vocals do play quite well here, being forward-facing. Combined with a decent seal, this makes the Truthear Hexa a comfortable daily driver—or not at all if you can't fit the thick nozzles in your ear canals! The rise into the upper mids starts from around 800 Hz, which follows the growing HRTF theories, although that slight hump past 1 kHz does make female vocals feel airy and not as weighty as I'd like. This is made worse by the pinna gain being slightly shifted to higher frequencies and is really the only misstep in tonality that I can fault Truthear for. It's not a particularly technical set in absolute senses though—imaging is fine and soundstage is about average for IEMs, not the most resolving set and sometimes trailing ends of tones clashed with the subsequent leading edges owing to a relatively slow playback. The treble region can be hit or miss depending on your preferences too, and once again I thought the Hexa was a case of good tonality let down slightly by the drivers. Piano keys and harps came off veiled and violins sounded muffled to where it's not a set I'd particularly use for classical music.

Comparisons

There is so much competition in the price range the Truthear Hexa operates in that I can't even cover everything in two graphs. As such, I chose to go with some of the leading/newer contenders along with those that merited discussion here. In round one, the Hexa takes on the MOONDROP Aria Snow Edition, the DUNU TITAN S, and the Tripowin x HBB Olina SE. The first two match up price-wise whereas the Olina SE does cost slightly more, and all three competitors are single-DD sets. The MOONDROP Aria Snow Edition on the other hand is not going to be my recommendation in multiple different ways, ranging from questionable build and cable all the way to mediocre detail retrieval. The original Aria still has build issues but I can certainly see people preferring it over the Hexa. The TITAN S is another flavor altogether going more neutral-bright and I do prefer its tonality, although I have to again give the edge to the Truthear Hexa for better quality bass and nicer vocals presentation. I'd actually recommend spending the extra $20 and pick the Olina SE here because it does bass even better while also having a more natural timbre for instruments. The Hexa does have more air although it felt weak on delivery so I'd not really use that as a point in favor of Truthear.


Round two goes planar with the hot new kids on the block in the form of the 7Hz x Crinacle Salnotes Dioko and the ridiculous MOONDROP STELLARIS. Both of these offer mediocre fit and comfort, with the STELLARIS one of the worst fitting IEMs on the market, but are both extremely resolving sets. If you don't mind the aesthetics and potential fit issues of the Dioko in addition to a somewhat overly-dampened presence in the higher frequencies, it is worth considering, even with the slightly higher cost compared to the Truthear Hexa. There is no way I would ever tell you to pay even higher a cost for the STELLARIS, and I'd skip it at half the cost anyway. The ThieAudio Legacy 2 is really only here because I felt bad about the Hexa being the only hybrid on this page. It's a 1 DD, 1 BA set that looks and fits nicely but otherwise doesn't do much to merit being in the discussion, offering decent bass but that's about it.