Truthear x Crinacle Zero:RED IEM Review

[abdo123]

Do you have a link for that eq post please? (or do you mean you would like him to do one?)

It's in the video, if you want the IE2019 tuning then you need this.

 

[Black98]

I am continuously following the testing and comments of BLUE ZERO, so I have collected some opinions (such as low-frequency distortion under louder pressure levels) and integrated them into the new RED ZERO. Thank you for your hard work @amirm, and all your opinions and comments.

 

[IAtaman]

I never got the Kiwi Ears Cadenza, but it is only $35 and damn close to the Red:

I have the Kiwi Ears Cadenza. It did not work for me at all. Those 8K and 12K peaks that one usually attributes to measurement artifacts, they are real with Cadenza. I am yet to hear Red of course, but I doubt it will be anything like the Kiwis. And to me this gives the impression that random measurement results with random rigs and no references do us no favours, might be quite the opposite even.

 

[abdo123]

Good for Crinacle to post an EQ to mimic the sound of Red on the Zero. The Red sound is tempting to me but I found myself consistently preferring the sound of the Zero. It's just a bit more exciting. Maybe my 50+ old ears like the little bit of treble boost.

Can't help but shake that the Blue is slightly harsh now compared to the RED tuning.

 

[Grooved]

Impressive distortion results!
Thanks @amirm for the review, ordered this Red version instantly. Already having the Blue ones, I will compare both but I'm pretty sure the Red will be my favorite.

@crinacle , I tested several EQ on the Blue ones since one week and tried to mix with them (even if setting correctly things like reverb for example remain hard for me with headphones or IEM compared to speakers), I ended up with mix that was almost correctly translated on speakers after using an EQ being based on the IEF Neutral 2023 that I manually tweaked to get the low end between Neutral and Harman and some other little things, and this EQ curve seems to be very close to what is measured on the Red ones, so fingers crossed, it may become my favorite set

 

[amirm]

But how can you determine that the measured group delay shows non minimum phase behavior without comparing it to the minimum phase group delay?

From experience. You are not trying to analyze an arbitrary system here. You have a specific situation where some characteristics are known such as reflections inside the cup. This is similar to modal response of the room where nulls appear. These are non-minimum phase regions where in theory you don't want to equalize. In practice, it may be worth trying since you want to smooth out the modal response if you can (assuming you have amplification power/dynamics in the speakers). Due to much smaller air volume inside headphone cups, these reflections/non-minimum phase region fall in high frequencies. And are easily seen by large peaks in Group Delay:

You can see my notation next to those sharp peaks in GD.

This example demonstrates that there is no virtually no behavior that is inexplicable by magnitude response, and the only way to know this for sure is by comparing the measured group delay to the minimum phase group delay to get the excess group delay (or by looking at the excess phase response).

While diagnostic value of GD is quite low, you do see things like the above example I post (internal reflections causing the messiness in the 1 to 5 kHz). Looking at the frequency response is not revealing:

In general, Group Delay is there for folks who ask for "timing information" in the review. You can use it or not. As for posting excess phase, Audio Precision software is not capable of computing that (or anything else outside of GD for that matter). I know REW has that but that is not what I use. So just learn the bit you need out of GD and leave it at that.

For any follows up, please use Master complaint thread. Review threads are not for general arguments like this.

 

[raif71]

I haven't been following the RED Project hype. If Crinacle has been trying out his RED tuning at audio shows, and then making adjustments, it does sound as if the RED concept started soon after release of the 'Blue'. Maybe simultaneously? I find it impossible to get my head around the speed and direction of budget IEM marketing.

 

[dustinyo]

Wow, we are really in a golden age of IEMs right now. This is impressive.

 

[crinacle]

I am continuously following the testing and comments of BLUE ZERO, so I have collected some opinions (such as low-frequency distortion under louder pressure levels) and integrated them into the new RED ZERO. Thank you for your hard work @amirm, and all your opinions and comments.

In case anyone needs context, this is the Chief Engineer for Truthear!

 

[jools]

But I JUST got the Blues...

 

[F1308]

Curious how people use wired 3.5mm IEM these days given almost everything has gone wireless. I have old Sandisk Sansa mp3 players I use on flights, but without noise cancelling, I don't see a good use for IEMs on flights.

I am tempted to buy these, but just don't see a use case.

Use case here...I love them.

Taikos are taikos, huge bells are huge bells, everything sounds as expected.

So many thanks to Crinacle, indeed.

And, let me ask, please, Crinacle: any chance to add wireless, lagless, high quality 24bit/48-kHz , stereo to your next IEM...?

Say yes !!!!

 

[Robbo99999]

That’s going to be my first test, once I get mine.

Are you gonna EQ them both to the same curve? I think that would be the most valid approach. And see if you can work out a way that you're listening at the same levels.

 

[Robbo99999]

View attachment 286990

Ha, yes, except neither are controversial and both very similar!

 

[F1308]

In practice the small differences in FR response between these and the originals look to be less than the differences you might experience by using foam tips vs silicones or a poor fit vs a good fit. I can't see any advantage of these over the original except the obviously better distortion measurements. But are these even audible? I mean at any normal level that is not so loud as to be damaging. I have the originals and even with bass heavy tracks played loud I don't notice any distortion. If I didn't own the originals I might prefer to buy the new version, maybe. But unless you listen at truly astonishing and deafening levels and have no access to EQ is there any advantage? I can't see it.

The obvious advantage is simply that by supporting developers with money we keep the door open for them to bring even better products in the future.

 

[F1308]

Sep 14, 2022 TRUTHEAR x Crinacle Zero
May 20, 2023 Truthear x Crinacle Zero:RED
It only takes 9 months for a new generation with notable improvement.

February 24 is around the corner !!!!!

 

[Trell]

The only problem I have with the Zeros (and with other IEM) is hearing my own breath and pulse far too loud.

I’ve the same issue as you with IEMs so I use them seldom. The Truthear Zero (blue) are nice but I find them a bit too bass-heavy for my taste.

 

[Chyżwar]

It might not be just about FR, although it is obviously a very important aspect. I have bought the Hola, after having bought the Truthear Zero a little while ago after @amirm review.
To me the difference between what I hear from the Zero and the Hola, is a lot more than the variation in FR response. I am eagerly waiting for @amirm review of the Hola, hoping it will shine some lights on why they are so different. My money is on level of distortion, but TBH, I am clueless.

I don't think there is any connection between THD and subjective perception of sound quality (at least until they are very large and start to be audible, which is not the case here).


Zero (Blue)

Hola

 

[Koeitje]

Medium. Larger than the FiiO FH's.

Alright, I don't know those FiiO's. Years ago I had Hifiman RE-400's and those were too big. Just went only headphones after that.

 

[Matias]

On a side note, I am glad to see Crinacle move to a sloped diffuse field reference for tuning. It makes a lot more sense, as I mentioned here. I always felt that the statistical "tune how you like it, take the average" approach of Harman OE/IEM was too simplistic...

Now we are finally getting to a dream of mine: move from speakers to headphones to IEMs and the tonality will remain the same. Of course soundstage will always be portrayed differently because of how it is influenced by room reflections etc. But I remember like 10 to 15 years ago (getting older...), listening to each category (speakers, headphones, IEMs) each had total crazy tunings among themselves and even more between them. How is a song supposed to sound good in all of them?? 100% circle of confusion.

Hopefully my sons and grandsons will laugh at this as a thing from the past.

 

[MayaTlab]

@amirm I have observed something for which I'd like to know what your opinion on it would be, and if you would be interested in doing a little experiment to clarify it if you don't mind.

First I'd like to single out the rather low sample variation among the samples @crinacle has measured so far, this seems to be quite excellent ! Congrats to Truthear and Crinacle for this.

What I noticed is that in the 1-6kHz region, ASR's measurements seem to deviate quite a bit from the rest of the measurements that have been published so far :

Now unless ASR stumbled on an outlier, I think that it can be presumed for now that sample variation isn't causing this.

A few precisions first on the measurement rigs (feel free to correct me if I'm wrong here) :

- Crinacle uses a clone coupler with metal canal extension, but has the means to compare it to an original GRAS coupler I believe, and can compare the metal canal extension with the pinna (KB500x, 43AG).
- Resolve uses a GRAS RA0402 high res coupler with the metal ear canal extension, but can also compare the results with a KB500x anthropometric pinna, mounted in a 43AG.
- Listener uses a clone coupler with the metal ear canal extension
- VSG uses a clone coupler with the metal ear canal extension, but can also compare the results with a clone KB0065 pinna.
- ASR uses a GRAS 45CA with high-res coupler and anthropometric KB501x pinnae. Interestingly, unless I'm mistaken, these are directly coupled to the coupler with a fairly simple screw-in thread that is different from how the KB500x couples to GRAS couplers when using the 43AG / KEMAR format.

Other precisions :
- "A" is the part of the spectrum I'm mostly interested in here.
- I would ignore the wiggles pointed by the arrows ("B"). They could possibly be caused by the IEMs not being stabilised well enough in the anthropometric pinna. This can usually be more or less successfully be solved by using putty to better couple IEMs to the pinna or metal canal extension.
- The differences seen at higher frequencies ("C") can arise from various factors such as insertion depth, use of a high-res original coupler vs regular original coupler or clone couplers (different damping), or the use of different tips. I would not over-analyse this region, this isn't what I'm concerned with here.

A few months ago I purchased a couple of the newer, softer clone pinnae that have recently appeared on Aliexpress. Unlike the previous, stiffer pinnae that aimed at cloning the KB0065 pinnae, these are a copy of the KB501x anthropometric pinnae (not the KB500x anthropometric pinnae !). Just like the original KB501x pinnae (don't hesitate to correct me if I'm wrong here !), they directly couple to the clone couplers via a simple screw in system :

Well I found myself quite puzzled by the results when comparing these clone KB501x pinnae with the metal canal extension, as they seemed to boost the response in the 1-6kHz region - sufficiently so that I have so far found them not useful for IEM measurements. Here is one of my clone couplers (not a good one, but that's not important for this post's subject), with one of my Moondrop Chu, comparing the response using the metal canal extension and the clone KB501x pinna :

Two observations :
- The use of the clone KB501x pinna dampens the resonance around 8kHz, compared to the metal ear canal extension.
- More relevant to the subject : it boosts the response in the 1-6kHz region in a way that trends strikingly similarly to ASR's measurements of the Zero Red vs other measurements.

It took me a while to start having an idea as to what could cause that, until I had an epiphany and introduced a ring of soft silicone deep into the metal ear canal extension :

This is the result, compared to the two traces above :

This isn't a 1:1 equivalent to the use of the pinna, but similar trends have emerged : a dampening of the resonance, and a boost around 1-6kHz (mainly 3-6kHz here).

I observed that when screwing the clone KB501x pinna into the clone coupler, it would create a choke point that is not too dissimilar from the choke point the silicone ring creates inside the metal canal extension. This is a photo of the clone KB501x pinna screwed into the external body of a disassembled clone coupler, seen from the coupler's point of view :

Now I'd be surprised that an original GRAS test rig would suffer from such an issue, and at first I simply put the issues I encountered with these clone couplers and pinnae to the most plausible hypothesis that "clones suck". I also am not certain that a similar discrepancy exists between all 45CA-10 measurements and measurements performed with metal canal extensions or 43AG/KB500x combos, so maybe this is just a coincidence. But some issues with pinna to ear simulator coupling have already been experienced with original GRAS equipment, so I don't think that it can be fully ruled out either.

Do you you confirm that the 45CA + KB501x system uses a similar, plain screw-in system to couple the pinna to the coupler ? Do you think that it would be interesting to check how the Red Zero would measure using only the coupler and metal canal extension, and compare the results with how they measure using the KB501x pinna ?