7Hz x Crinacle Zero:2 IEM Review

[MC_RME]

It's a pity @amirm doesn't do fun measurements like that - what is the maximum SPL or milliwatts that cause drastic rise in THD at 20 Hz. I don't have the equipment to do that. With normal headphones one can shove earplugs into the ear canal, then listen at lowered volume to the point where the drivers break up (old, but very efficient trick). With IEMs this obviously isn't possible.

Especially with the difference that I observed between Zero2 and Blue Zero 2 I would really like to see this verified as measurement.

 

[sikamikaniko]

Hi everyone,


I recently got the 7Hz Zero 2 and have noticed that vocals sound unusually recessed — almost pushed far behind the rest of the mix. For example, when listening to “Billie Jean,” I hear the shaker on the right channel very loud and clear, but not harsh or piercing; it just sounds very upfront compared to the vocals. Meanwhile, the bass and drums also seem much more forward than the voice.
I’m coming from AKG K-702 headphones, so I’m very used to their sound profile, especially their clear and upfront mids and vocals. While the Zero 2 are lightyears ahead in soundstage and separation, the vocal presentation feels quite different and somewhat recessed.
I’ve tried both the stock tuning and applying the AutoEQ Harman In-Ear 2019 preset via Wavelet on Android. The EQ helps somewhat, but the vocals still sound pushed back compared to other elements. Without any EQ, the issue is even more pronounced, with stronger bass presence and still recessed mids.
Is this kind of vocal presentation typical for the 7Hz Zero 2? Or could it be due to fit, seal, or some other factor?
I’d appreciate any insights from those familiar with these IEMs.

 

[stefanovesa]

In my case the bass is not strong at all, I think that the seal is not perfect for my ear channel

 

[Robin L]

Hi everyone,


I recently got the 7Hz Zero 2 and have noticed that vocals sound unusually recessed — almost pushed far behind the rest of the mix. For example, when listening to “Billie Jean,” I hear the shaker on the right channel very loud and clear, but not harsh or piercing; it just sounds very upfront compared to the vocals. Meanwhile, the bass and drums also seem much more forward than the voice.
I’m coming from AKG K-702 headphones, so I’m very used to their sound profile, especially their clear and upfront mids and vocals. While the Zero 2 are lightyears ahead in soundstage and separation, the vocal presentation feels quite different and somewhat recessed.
I’ve tried both the stock tuning and applying the AutoEQ Harman In-Ear 2019 preset via Wavelet on Android. The EQ helps somewhat, but the vocals still sound pushed back compared to other elements. Without any EQ, the issue is even more pronounced, with stronger bass presence and still recessed mids.
Is this kind of vocal presentation typical for the 7Hz Zero 2? Or could it be due to fit, seal, or some other factor?
I’d appreciate any insights from those familiar with these IEMs.

Here's a frequency graph for the 702s, overlaid on the Harman graph:

The 702 has a major "bump" centered on 2.5 kHz. That would make vocals stick out from the mix compared to the zero-2s (or any other transducer with comparatively neutral response in that region).

Meanwhile, I'm waiting for my second pair to arrive. I just got out of the shower, the inside of my right ear was wet and the sound on that side disappeared. Gradually, some of the sound re-appeared but not all. Lesson learned. Ordered another pair. Love the sound of these IEMs, best bass I've heard from IEMs/headphones so far. For $25 can't think of a better audio purchase.

 

[CedarX]

I recently got the 7Hz Zero 2 and have noticed that vocals sound unusually recessed — almost pushed far behind the rest of the mix.

I’m coming from AKG K-702 headphones,

I’ve tried both the stock tuning and applying the AutoEQ Harman In-Ear 2019 preset via Wavelet on Android. The EQ helps somewhat, but the vocals still sound pushed back compared to other elements. Without any EQ, the issue is even more pronounced, with stronger bass presence and still recessed mids.

As @Robin L said, the K702 has its own sound “profile”. The important point is that it works for you and you like it.

You’ve EQ’d the Zero2 to the Harman in-ear target: that’s a good starting point. What I would do then is EQ’ing further to mimic the K702 based on Oratory error histogram. See if you like it, and “explore around”: you may get something you like even more…

What’s great about Zero2: it’s inexpensive, FR is a good starting point to EQ further, distortion is low enough to EQ to pretty much whatever you like… As long as comfort & fit is ok for you, there is really no objective reason to give up and try another IEM…

 

[mc.god]

As @Robin L said, the K702 has its own sound “profile”. The important point is that it works for you and you like it.

You’ve EQ’d the Zero2 to the Harman in-ear target: that’s a good starting point. What I would do then is EQ’ing further to mimic the K702 based on Oratory error histogram. See if you like it, and “explore around”: you may get something you like even more…

What’s great about Zero2: it’s inexpensive, FR is a good starting point to EQ further, distortion is low enough to EQ to pretty much whatever you like… As long comfort & fit is ok for you, there is really no objective reason to give up and try another IEM…

Or he can get a super cheap TRN MT1

 

[phoenixsong]

Or he can get a super cheap TRN MT1

View attachment 461223

Ohh I've had that before, as well as the K712pro and Zero 2. The MT1 is actually "listenable" to me without EQ. TRN as a company has done questionable things in the past though, so I still would avoid recommending their products, affordable though they might be

 

[sikamikaniko]

The 702 has a major "bump" centered on 2.5 kHz. That would make vocals stick out from the mix compared to the zero-2s (or any other transducer with comparatively neutral response in that region).

It's not just a matter of different tuning between the K702 and the Zero 2. The Zero 2 actually has decent soundstage and noticeably better separation — but at the same time, it pushes vocals way too far into the background.
The K702 isn’t my only point of reference — it’s just the one I’m most used to. I’ve also used things like the Sony MDR-7506, various KZs, Xiaomis, and other cheap, low-quality gear… and none of them bury the vocals like the Zero 2 does.

You’ve EQ’d the Zero2 to the Harman in-ear target: that’s a good starting point. What I would do then is EQ’ing further to mimic the K702 based on Oratory error histogram. See if you like it, and “explore around”: you may get something you like even more…

I’ll try what you suggested and report back on how they sound to me.

I really like them compared to the AKGs (and pretty much anything else I’ve owned) in the sense that now, without even trying, I can clearly distinguish the kick drum from the bass. I’ve also discovered just how much saturation is used when recording or processing electric bass — and not just in rock music.
After all, for the €14 I paid, I can afford to run all the tests I want.


Thanks, everyone!

 

[staticV3]

No buried vocals on my Zero:2.

All that's missing to my ears is a bit of upper treble, but that's easily done thanks to the smooth treble response, see here:

7Hz x Crinacle Zero:2 IEM Review

A decent dongle is cheap, an excellent one not expensive either. No reason to use junk 3.5mm out of a laptop or cell phone IMO. Agree for laptops, but I use the smartphone 3.5 output, because I'm not concerned about max sound quality when on the move, generally on noisy bus using 5€ iems, and...

www.audiosciencereview.com

 

[roladyzator]

It may be be that your hearing expects more ar 2 kHz when using IEMs. Since there are people who say Harman Target has too much energy there - then I presume there will be folks who prefer even more.

I'd check if boosting 2 kHz with a wide filter would help with the vocals

 

[mc.god]

Ohh I've had that before, as well as the K712pro and Zero 2. The MT1 is actually "listenable" to me without EQ. TRN as a company has done questionable things in the past though, so I still would avoid recommending their products, affordable though they might be

I used them for a long time as daily beater for home\work commuting, always listened to them without EQ and yes, absolutely "listenable" if you are not particularly sensible in the pinna gain region.
For commuting they are now replaced by a more balanced and even cheaper KZ EDX Lite, but still own and use them for work calls when working from home

 

[sikamikaniko]

After several tests, both with EQ and different sources/players, what I’m noticing is that anything centered from around 800 Hz and up tends to fall into the background — vocals, snare attack, etc. If any of those elements (like background vocals, keys, etc.) are panned to the sides, they come through much more prominently, especially around the 5 kHz region.

Since this seems to only happen to me, I guess I must have wooden ears. I’ll need to do some mono/stereo tests to see what results I get.

Thanks everyone for the help! I’m going to keep them, because in fact, I do like them.

 

[Adornix_jitz]

After several tests, both with EQ and different sources/players, what I’m noticing is that anything centered from around 800 Hz and up tends to fall into the background — vocals, snare attack, etc. If any of those elements (like background vocals, keys, etc.) are panned to the sides, they come through much more prominently, especially around the 5 kHz region.

Since this seems to only happen to me, I guess I must have wooden ears. I’ll need to do some mono/stereo tests to see what results I get.

Thanks everyone for the help! I’m going to keep them, because in fact, I do like them.

on this page you can do a lot of tests to check your IEM (and - of course - your hearing): Audio Check

 

[ehabheikal]

on this page you can do a lot of tests to check your IEM (and - of course - your hearing): Audio Check

I see you have 4nc like me. Did you try wavlet with it if you have android. I have a file for wavelet that is great with it search for it here.

 

[rsqt]

Take the frequency response of your ear. Everybody should do this, otherwise it is difficult (or not possible) to differentiate whether it is your ear or the IE.
I did so and have a light dip in the 4khz area and eqing it makes a very big difference because many instruments overtones are there.

 

[Adornix_jitz]

I see you have 4nc like me. Did you try wavlet with it if you have android. I have a file for wavelet that is great with it search for it here.

thx for your tip! But for casual listening (like Podcasts or YT) I'm using the HearID + soundcore signature of the Soundcore App itself and for Music I'm totally convinced by the PEQ feature from UAPP App.

 

[JD1]

Here are some thoughts about the EQ.
Please report your findings, positive or negative!

Notes about the EQ design:

• The average L/R is used to calculate the score.
• The resolution is 12 points per octave interpolated from the raw data (provided by @amirm)
• A Genetic Algorithm is used to optimize the EQ.
• The EQ Score is designed to MAXIMIZE the Score WHILE fitting the Harman target curve (and other constrains) with a fixed complexity.
  This will avoid weird results if one only optimizes for the Score.
  It will probably flatten the Error regression doing so, the tonal balance should be therefore more neutral.
• The EQs are starting point and may require tuning (certainly at LF and maybe at HF).
• The range around and above 10kHz is usually not EQed unless smooth enough to do so.
• I am using PEQ (PK) as from my experience the definition is more consistent across different DSP/platform implementations than shelves.
• With some HP/amp combo, the boosts and preamp gain (loss of Dynamic range) need to be carefully considered to avoid issues with, amongst other things, too low a Max SPL or damaging your device. You have beed warned.
• Not all units of the same product are made equal. The EQ is based on the measurements of a single unit. YMMV with regards to the very unit you are trying this EQ on.
• I sometimes use variations of the Harman curve for some reasons. See rational here: https://www.audiosciencereview.com/...pro-review-headphone.28244/page-5#post-989169
• https://www.audiosciencereview.com/...pro-review-headphone.28244/page-6#post-992119
• NOTE: the score then calculated is not comparable to the scores derived from the default Harman target curve if not otherwise noted.
• Occluding IE devices generally must have very good fitting/seal in the user's ear canal for best performance.
  please spend a few minutes to pick up the best ear tip... Be sure to perform this step otherwise the FR/Score/EQ presented here are just worthless.
• 1. more bass = better seal
  2. More isolation from the outside world = better fit
  3. Comfort

Great L/R match.

I have generated one EQ, the APO config file is attached.

Score no EQ: 77.0%
Score Amirm: 82.9%
Score with EQ: 95.8%

View attachment 335128
Knowles Target, the scores are NOT comparable

View attachment 335129

THD with different plot

View attachment 335133

I like your harman curve eq however using power amp eq and listening to DnB I prefer it with 57% bass nob on.
Using fosi ds2 with s21 ultra.

Je sui criminal


However, these IEMs are really amazing.

 

[Boobisha Chodhankar]

So I got Zero 2 and Truthear Hexa and Zero didn't fare well in comparison. No miracle happened - $20 IEM sounded like what you'd expect from a $20 product. I guess that drop from 4K to 8K makes sound dull and muffled. Also the cheap build quality plays a big part in how the sound is perceived.

 

[staticV3]

So I got Zero 2 and Truthear Hexa and Zero didn't fare well in comparison. No miracle happened - $20 IEM sounded like what you'd expect from a $20 product. I guess that drop from 4K to 8K makes sound dull and muffled. Also the cheap build quality plays a big part in how the sound is perceived.

4-8K is identical on both, but the Hexa has 5dB less bass and slightly more treble extension (drops at 16k vs 14k):


Try a single PEQ filter at 20Hz, -4.6dB, Q 0.19 on the Zero2, that'll give it the same bass response as Hexa, removing the dull and muffled sound (I don't believe the treble difference is consequential).

Edit:
Personally, here's how I prefer EQing my Zero2: https://www.audiosciencereview.com/...-zero-2-iem-review.50534/page-59#post-2005646

 

[Boobisha Chodhankar]

4-8K is identical on both, but the Hexa has 5dB less bass and slightly more treble extension (drops at 16k vs 14k):
View attachment 465910

Try a single PEQ filter at 20Hz, -4.6dB, Q 0.19 on the Zero2, that'll give it the same bass response as Hexa, removing the dull and muffled sound (I don't believe the treble difference is consequential).

Edit:
Personally, here's how I prefer EQing my Zero2: https://www.audiosciencereview.com/...-zero-2-iem-review.50534/page-59#post-2005646

I've tried EQ presets for Zero 2 in PowerAmp but it still sounds cheap to me. Might be a psychological thing.