Fit and Comfort

Seen above is the right channel of the Truthear x Crinacle ZERO 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. 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

There are plenty of IEMs which use a single dynamic driver all the way from a couple of dollars to over $1000, and many others which uses one or more dynamic drivers in a hybrid configuration as with the DUNU VULKAN we recently saw. But I can count on one hand the number of IEMs I am aware of that use two dynamic drivers per side, with some inexpensive KZ sets doing so recently before someone tested them (and others) and found only one driver contributing to the sound. Needless to say then that when Truthear announced itself as a new brand and the use of two dynamic drivers, people were skeptical. This is partly where the collaboration with Crinacle and marketing from SHENZHENAUDIO came in handy, and the more I looked into this the more I was happy to have agreed to do this review.

The Truthear x Crinacle ZERO uses two dynamic drivers of the same composition—a liquid crystalline polymer (LCP) composite diaphragm and polyurathane (PU) surround/suspension—of different sizes. The larger 10 mm driver acts exclusively as a subwoofer handling sound from ~180 Hz and below only, with the smaller 7.8 mm driver catering to the rest of the audible frequency range. The larger driver we saw was placed further away from the nozzle so that the longer acoustic tubing effectively helped act as a low-pass filter, and the aim here is to have a substantial sub-bass and lower bass presence akin to what Crinacle prefers. This also happens to in line with the Harman 2019 v2 in-ear target, and that happens to be the goal with the tonality of this set. There's a bit more known about the drivers, including the use of N52-grade magnets and two types of voice coils, but the bottom line is these come together to make for a pair of IEMs that are somewhat tough to run compared to average owing to a low rated impedance of 10 Ω and a low rated sensitivity of 117.5 dB/Vrms that corresponds to 97.5 dB/mW. This means that the Truthear x Crinacle ZERO asks for ~2/18 mW to hit transient spikes up to 100/110 dB respectively with more current required than power. Most decent dongles will still be fine although a portable DAC/amp might not be a bad idea if within your budget—especially if you want to go with a Bluetooth option or even a DAP for portable use. If not on the go, space is less of an issue, but the relatively short cable might still be a potential handicap if using a PC as the audio source.

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 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 x Crinacle ZERO. 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 10 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. Measurements taken after 20 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 even better, 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 x Crinacle ZERO 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. In addition, and knowing that this set was deliberately tuned to appeal to the Harman research crowd, I also have the average response plotted against the 2019 v2 Harman in-ear target.

A quick look at both plots above confirms a couple of things including that these IEMs were not just tuned with Crinacle's IEF neutral + bass boost as with pretty much all his other collaborations. I wanted to see something different from reviewer collabs that were becoming same-old in a world getting increasingly dominated by bass neutral tuned sets coming out of Asia, so just by that aspect I can appreciate this product coming to fruition. Second, the Truthear x Crinacle ZERO is very faithful to the Harman target and in that regard it's a job well done in meeting expectations set forth by marketing. If you are a fan of the Harman target then this should be right up your list. The popular MOONDROP Variations is another example of a set that follows the 2019 v2 Harman in-ear target, but happens to be priced out of most people's budgets. This set costs significantly less and can be a more obtainable manner to test it out.

Third, and now we get to my personal preferences and subjective analysis, it's not a set for everyone. Indeed, the tonality is somewhat aggressive on two separate fronts for me. Take that bass response, for example, where the neatly tucked in rise of ~9 dB from 200 Hz down might not seem like much but in fact punches above its weight owing to a punchy 10 mm driver dedicated to being a subwoofer. There were a couple of readers who asked me whether this set slams, and the answer would be yes thus. At the same time, there is a risk of the Truthear x Crinacle ZERO being noted more for the lower bass which isn't ideal for a lot of music genres. The small-but-noticeable dip from 50 Hz down wasn't an issue for me given there is still plenty of rumble for EDM and the like, however bass guitars lost their magic on the set and I suspect many fans of metal music might be left wanting more from the mid/upper-bass and lower mids. There is detail throughout, but nuances to notes are lost as I hear more the base fundamental tones foremost and then a slower decay than ideal.

The upper bass is cleaned up to isolate the mids, which is done in a manner that I am not a fan of but you can blame Harman Kardon for that. I will give that the mids are extremely clean though, and this helps with instrument separation while also keeping vocals forward and relevant. This can be fit dependent, so I will note again that I had an excellent seal in my ears. I can see this being a great everyday set for conversations and general media consumption too, ensuring it is not just a one-trick pony. It's also hard to make out the crossover although the set can appear slightly warm for male vocals if you are looking for it. Otherwise I am a fan of the performance in the mids, and will note that a more intimate soundstage here plays well owing to the slammy nature of the drivers. Imaging won't be high up on the strengths list though, with a fairly narrow cone upfront that worked well enough to be precise outside of right around the ears.

The rise up into the upper mids starts from ~800 Hz, which again follows most established HRTF practices led by research today. From this point on, there's a relatively massive 10-11 dB of pinna gain centered around ~2.5-3 kHz, and this can make female vocals/higher frequency fundamentals quite bright to even shouty for many. Given the mainstream audience's reception of bass over treble frequencies, I suspect this is going to be the primary source of discontent for potential customers and word-of-mouth going forward. There's also a small peak at 6 kHz in my ears which can be irksome with some string instruments and brass wind musical instruments such as trumpets, and it can accentuate sibilance already found in some tracks. Jazz music, and acoustic jazz in particular, can be irksome here. I also found the ear canal resonance to be closer to 8-8.5 kHz in my case, but it wasn't unpleasant and generally most of the treble behavior was more than acceptable. It's not a set I'd personally use for complex orchestral pieces where the smaller, longer range dynamic driver is trying to do a lot, but I'll give it fair dues for achieving natural timbre across the board when listening to single instrument classes, including piano and violin pieces.

Comparisons

At this point I might as well tell you that the Truthear x Crinacle ZERO costs all of $50, and maybe your perceptions might have changed for the better knowing this. I don't have a lot of experience dealing with IEMs that are in the $50 or under price range, with several reviewed units costing significantly less such as the FiiO x Jade Audio JD3, the MOONDROP Chu, the Tripowin Lea, and the KZ EDA all being easily bested by the Truthear x Crinacle ZERO as an overall package, adherence to target tonality, technical performance, and also extremely subjective aspects including aesthetics. Neither of those four are as detailed either, and this is clear step up even with the vastly different tuning. Then there's the $50 Tripowin TC-01, which is another single DD set as with the other mentioned contenders here, and it is a good example of V-shaped tuning done well on a budget. I'd still take the Truthear x Crinacle ZERO over the TC-01 for simply being better balanced and more articulated, and it arguable does bass and treble better too while easily besting everything else here in the mids. Overall this is a pretty comfortable win for Truthear.


As such, I wanted to see whether this can push the value-for-money boundaries further by expanding to the $100 price range. There are many entries here which are bested too, such as the BLON BL-A8 and the ThieAudio Legacy 2 in some respects even though personally I might still pick the Legacy 2 over this. But the real competition comes in the form of the MOONDROP Aria, the DUNU TITAN S, and the Tripowin x HBB Olina. There's a newer Aria SE being tested as we speak too, and note that every single set outside of the ThieAudio Legacy 2 (hybrid) and the Truthear x Crinacle ZERO use a single dynamic driver without any crossover to worry about. I'll give props to Truthear for going this route and getting people to talk about it accordingly, and it's executed well to where this is a genuine contender for those who simply want something different. Note how everything here is tuned very similar to each other, with even some planar sets going this route as we shall soon see. Then there's the V-shaped tuning here too, as with the FiiO FD3, leaving an open, untapped market for the Harman tuning crowd that now finally has a legitimate contender. The Truthear x Crinacle ZERO actually has more bass presence than the named three in the plot above despite the graphs showing otherwise, and this is down to that 10 mm driver along with the specific 200 Hz crossover implementation. It's not as detailed as either of the other three though, and I would personally pick the Aria or Titan S any day of the week, but there's a lot to like from the overall package and my talking about it in the $80-100 price range is already a win.