TruthEar x Crinacle Zero Red

Review unit provided by Shenzhen Audio:

TruthEar x Crinacle Zero Red Review

The Zero Red is essentially a version of the Zero that’s tuned to Crin’s preference target rather than Harman IE 2019, which is what the original Zero was aiming for.

So this is a bit of a data dump for all of the measurements that I’ve taken on it so far. I may add more in the future.

NOTE - These come with two different types of silicone tips, one with a smaller opening and the other with a larger opening. For most of these measurements, the default tips that were used are the ones with a larger opening. To see a comparison between the two, check the images further below.

B&K 5128 - 10dB slope

GRAS (Official RA0402) - 10dB slope

Note the normalization here - it’s different from where it is on the 5128 just because I wanted to show on that one how close the Red gets for the balance of fine-grained stuff in the treble. I may match them both at 1khz in a future image, however the compensated data is already there, so that should suffice.

Harmonic distortion (110dB)

This is at 110dB, which is not a representation of reasonable listening volumes. Rather, this is just testing the behavior at excess volumes. Here it is closer to 100dB, which is still louder than you’ll want to be listening, but it’s already under control.

vs Harman IE 2019

Vs IEF 2023

Tip comparison

Consistently the wide opening tips measure with more mid treble and less upper treble compared to the narrow opening tips. Same with the foam tips. Also some subtle differences in seal it seems as shown by the bass, but this was a consistent result for many reseats.

Foam Tips

Red vs Zero

10 ohm impedance adapter (included with the Red)

What’s interesting about this is that based on the statistical model that predicts listener preference, the Red is less likely to be preferred than the Zero, however I personally prefer the Red significantly.

Take these with a grain of salt - this is just a model.

For anyone who has heard both, please weigh in on which you prefer.


Definitely the stock tuning without the impedance adapter, I’ve shared more thoughts here for those interested: Truthear x Crinacle ZERO:RED In-Ear Monitors Review - Hype Machine | TechPowerUp

Measurements are also up now on my Squig database for those wanting to see how it compares, as well as create an easy EQ profile to go from Truthear ZERO to ZERO:RED to get some approximation of how the newer set sounds.


Only listened to them briefly but even with a short listen, they are certainly worth picking up if you are even remotely interested in them.


The Truthear Zero: Red solves most of my quibbles with the original Zero. Like its predecessor, it is an unqualified recommendation at its asking price. However, the IEM market has continued to progress in the year since the original Zero was released, and the Zero: Red is less revolutionary now than it might have been if released earlier. I cannot help but wish we had received this version of the Zero in lieu of the original.

My full review is up on my blog:


I’m still in the midst of writing my RED review but I did a number of measurements today using my normal clone 711 coupler.

Here’s the standard measurement. Some very minor channel imbalance. As usual, above the ~8 kHz artifact it’s not accurate and I would say I don’t notice that apparent 13 - 14 kHz peak.

Here it is against the 10 Ω Bass+ Adapter. Adds a healthy amount of bass and lower mids.

This is the same graph as the above with the Bass+ Adapter but unaligned. The key message here is that at the same volume, the Bass+ Adapter attenuates the full-range 7.8 mm driver to increase the perceived bass response. You’ll have to increase the volume to reach the same listening level as without the Bass+ Adapter. Most people already know this but just wanted to point it out for those unfamiliar.

Here is the original Truthear ZERO vs RED.

And if anyone was wondering how the Bass+ Adapter works with the original ZERO.

Finally, let’s look at the comparison between tips.

Here is the narrow vs. wide bore tips. Note I am using the Small size tips to do this measurement because the Medium size will slide out of the coupler. We can see that there is some difference but given that it’s in the treble region, I’d take it with a grain of salt and defer to Resolve’s measurements. I’d have to sit down and really AB test these tips to see if I can hear a difference and honestly, I think it’s less important than picking the one that best fits you.

Here is the Narrow vs. Foam tips. We can see that they look quite similar to one another.

Finally, here’s all the tips compared.

This next graph is more of a “proof” that the size of the tips (small vs. medium) should measure pretty much identically as long as you properly match the seal and insertion depth. I think most people already know this but wanted to include it here in case anyone was going to comment about how my measurements for the Narrow vs. Wide bore tips is wrong because I used the small tips.

Finally, whenever there’s a dynamic driver IEM with venting ports, people invariably want to know what happens if you block them. So here it is.

Looks like any hopes that blocking the vent will turn it into ungodly bass cannons ala the Tin Audio T2 have been thus broken.
And compared to the original ZERO.

The way this response looks reminds me of the 64 Audio Trio and Fourte actually… that weird mids hump.


Hey Construct,

I have a clone 711 coupler as well and I have a question.

Are you using REW to take your measurements, and if so, how can I get the colored header labels “sub-bass, bass… presence, brilliance” to show up on my measurements?

Is there any convolution filters (WAV files) available?



Hey @Smirk, in REW go into Controls and select “Show Frequency Bands” and it should show up just like this. I didn’t do anything else other than click that checkmark.


We aren’t presently offering IRs for convolution based EQ, but it’s something we’ll be hopefully rolling out in the near future!

Ah, thank you! It’s simpler than I thought

Has anyone yet compared the red to the kz hbb pr2 ? Just curious which one has the higher technical performance for <$50.

Hey everyone, finished my review a while back. You can find it here: Truthear x Crinacle ZERO: RED: Dissecting the Hype –

I’m currently writing a dedicated comparison review of it against a number of other budget IEMs which is why it’s not present in the article.

Here’s the cliffnotes summary of the review:

  1. The RED is the best <$100 IEM I’ve heard to date. My reasoning is because it has outstanding bass quality (though you don’t always hear it because it’s so subbass focused) and a very tightly reigned treble response without being overly dampened. The mids are tonally neutral with nothing to point out. Having either outstanding bass or tightly controlled treble alone is already a rarity within the IEM space, let alone in the budget realm. Having both in the same IEM at $55 is excellent.

  2. I have not heard every <$100 IEM that exists, including the Truthear Hexa. But if the Hexa was to be better (and not a sidegrade) than the RED to me, it would need to outdo both its bass and treble. This is with me already assuming it’s already better in resolution and soundstage.

  3. The other way to see it is: I’ve heard a lot of budget IEMs and most of them are me-too products with trade-offs in tuning against its peers. The RED is not one of them. I don’t see it as a “second-to-market” alternative to some other IEM. I see it as an IEM that stands alone.

  4. All that said, I don’t love the RED. I appreciate it. Many people have mentioned that it sounds unremarkable. I can see where that is coming from. To use a horrible cliche, the RED to me is like listening to a pair of studio speakers. They don’t sound interesting. They don’t have some sort of WOW effect. They aren’t “sweet” or “euphoric” or whatever audiophile term you want to use. They just sound tonally correct with very very little to complain about.


The RED is better than its peers, but it’s not immensely better. Some people were expecting night-and-day differences. It is not. It’s marginally better. Enough to be the “best” but my philosophy is always that if you already own something you enjoy and are satisfied with, there’s no need to go out and buy another just to upgrade to the “latest and greatest”. Nor will the RED’s reference-style signature be to everyone’s taste. The RED is fundamentally one man’s opinion of the best IEM tuning. While it happens to be a very good tuning, it has no more data than Harman’s In-Ear target in terms of audience preference.

And that’s kinda the point of the RED. If you have the money and want to explore Crinacle’s ideal target vs. the Harman target and contribute to the community discussion, by all means. After all, trying out new gear yourself to deepen your understanding of audio and enjoyment of music is the whole point of this hobby. You’ll even get an excellent IEM on top. And hey, if you want to vehemently disagree with me or anyone about the RED, $55 is a fair price of admission.


Might be worth picking up during the upcoming AliExpress summer sale on 6/18

I wonder if it will go on sale given how well its selling. Crin mentioned that they didn’t have enough stock so they’re kinda like on back order at the moment.

That popular, huh? How well, good for Crinacle.

Has anyone compared crin project red vs hbb kz pr2 yet? Similar price point but wondering which is the more technical set.

I’ve listened to both, and I think both kinda suck from a technical perspective. If you are going for a 1st iem I’d probably go with the red as the PR2 has some weird treble peaks. But overall both are decent. Yet sound like budget iems, not 200 dollar iems. Like if you have more expensive iems that you like, you won’t find value with either. I much prefer the Hexa, and that will go on sale for 67ish soon.

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Do you have a link or the approximate date the Hexa will drop to that price point as I would bite on that.

Yeah, probably on the 12-18 of this month. Amazon and Shenzin should have the sale. Expect Amazon to have the same sale. Really solid iem for the price. Most stores and such are doing a big sale for the middle of the year.

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Great review! I have had extremely similar experiences with the Red. It doesn’t quite hang with something like the Hexa, Timeless or Wu Hayday for technical performance, but it’s better tuned than all of them and anything else I’ve heard in that $200ish price bracket.

Well done, Crinacle!